23 Nov
2014
23 Nov
'14
12:53 p.m.
From: Holm Tiffe
I think the US should have modernized the entire
System long before
now..
Two words for you: 'installed base'. :-)
Sort of like QWERTY keyboards... :-)
Noel
23 Nov
23 Nov
1:15 p.m.
Noel Chiappa wrote:
At least my Keyboard ist QWERTZ :-)
The two words make sense, but only now. It is to late to change anything,
but in the past it was possible. We have taken the chance, the US not.
...
but sine you already have 240V outlets, it should be possible to change the
distribution slowly to 3 phase power.. it's a matter of time and the only
needed thing for compatibility are the transformers with modified
secondaries.
I don't think that this would ever happen since the US is the biggest US of
the world and other people are just dumb aliens, aren't they? :-)
But with that stone age power system you are stumbling over your own feet
all the time..
Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
From: Holm
Tiffe
I think the US should have modernized the entire
System long before
now..
Two words for you: 'installed base'. :-)
Sort of like QWERTY keyboards... :-)
Noel 
2:12 p.m.
On 2014-Nov-23, at 1:15 PM, Holm Tiffe wrote:
Noel Chiappa wrote:
>> From: Holm Tiffe
>
>> I think the US should have modernized the entire System long before
>> now..
>
> Two words for you: 'installed base'. :-)
...
The two words make sense, but only now. It is to late
to change anything,
but in the past it was possible. We have taken the chance, the US not.
...
but sine you already have 240V outlets, it should be possible to change the
distribution slowly to 3 phase power.. it's a matter of time and the only
needed thing for compatibility are the transformers with modified
secondaries.
I don't think that this would ever happen since the US is the biggest US of
the world and other people are just dumb aliens, aren't they? :-)
All these systems have their varying benefits and detriments.
Between fire safety, shock safety, simplicity, ease of wiring, power efficiency, copper
efficiency, they all present a varying mix of trade-offs.
In Germany you readily have 3-phase in your house, but 3-phase wiring is not as simple as
split-phase.
The ring system in Britain with fuses in the plugs provides a safety factor of
appropriately limited current at the wall.
On the other hand, in NA the vast majority of in-wall house wiring is done with #14
wire(15A circuits), which is a lot easier to work than whichever gauge Britain uses for
25A or 32A circuits.
The benefit of the North American split-phase system vs EU/Britain is you have the energy
& copper-efficiency of 240V available for heavy appliances, but you have the safety
factor throughout the house of never having more than 120V between you and earth.
Yes, it makes me a little nervous having 15A available in the simple lamp socket at the
end of #18 wire, but it would make me more nervous if it was 240V at 3A.
But with that stone age power system you are stumbling
over your own feet
all the time..
NA has gone through various evolutions: getting rid of 25Hz, getting rid of DC mains,
requiring grounded outlets as standard, in my jurisdiction (for example) distribution
('pole-top') has evolved from 12KV to 25KV, etc.
The split-phase system may be the oldest but for residential use it's quite elegant
and efficient. 3-phase is there for where it's needed, commercial or multi-unit
residential buildings, it's done for smallish pump-houses within residential
neighbourhoods. In the big picture I haven't seen anything to suggest an overall
benefit to changing to some other system.
One could well suggest the reverse, that EU move away from that "highly
dangerous" 240V system.
2:27 p.m.
Brent Hilpert wrote:
[..]
NA has gone through various evolutions: getting rid of 25Hz, getting rid of DC mains,
requiring grounded outlets as standard, in my jurisdiction (for example) distribution
('pole-top') has evolved from 12KV to 25KV, etc.
The split-phase system may be the oldest but for residential use it's quite elegant
and efficient. 3-phase is there for where it's needed, commercial or multi-unit
residential buildings, it's done for smallish pump-houses within residential
neighbourhoods. In the big picture I haven't seen anything to suggest an overall
benefit to changing to some other system.
One could well suggest the reverse, that EU move away from that "highly
dangerous" 240V system.
Oh yes? as far as I know that is the Voltage most countries in the world
use... and the americans in their split phase system too. :-)
I don't wanted to kick you to convert this now ... :-)
going to sleep now, it's 11:27PM here..
good night,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
3:05 p.m.
On 2014-Nov-23, at 2:27 PM, Holm Tiffe wrote:
Brent Hilpert wrote:
[..]
Yes, one of the lasting legacies of empire.
NA has gone through various evolutions: getting rid of 25Hz, getting rid of DC mains,
requiring grounded outlets as standard, in my jurisdiction (for example) distribution
('pole-top') has evolved from 12KV to 25KV, etc.
The split-phase system may be the oldest but for residential use it's quite elegant
and efficient. 3-phase is there for where it's needed, commercial or multi-unit
residential buildings, it's done for smallish pump-houses within residential
neighbourhoods. In the big picture I haven't seen anything to suggest an overall
benefit to changing to some other system.
One could well suggest the reverse, that EU move away from that "highly
dangerous" 240V system.
Oh yes? as far as I know that is the Voltage most countries in the world
use ... and the americans in their split phase system too.
:-)
As I said, with the split phase-system you have 240V available but not more than 120V
between you and earth.
There's a big difference there compared to 240V to earth.
(The neutral/common is bonded to earth in the EU, isn't it?)
I don't wanted to kick you to convert this now ...
:-)
going to sleep now, it's 11:27PM here..
good night,
5:46 p.m.
On 23/11/2014 22:12, Brent Hilpert wrote:
The benefit of the North American split-phase system
vs EU/Britain is
you have the energy & copper-efficiency of 240V available for heavy
appliances, but you have the safety factor throughout the house of
never having more than 120V between you and earth.
That's not as much of a safety factor as many people think, indeed
possibly not at all. It's true that 230V will give you more of a jolt
than 120V, and more so because human body resistance drops slightly at
higher voltages. Nevertheless, there's a strong argument that a 230V
jolt is more likely to throw you off the conductor whereas 120V may be
more likely to make you latch onto it. It depends how you touch it,
obviously, but evidence suggests that (EHT excepted) the region around
100V-130V is about the most dangerous. I recall reading a discussion of
that as part of the European harmonisation of voltages, in connection
with 110V for site equipment. Evidently that was in part why the idea
of one live and one neutral with a single simple MCB or RCD was rejected
in favour of the split 55-0-55 system (proposed by the UK).
--
Pete
Pete Turnbull
24 Nov
24 Nov
12:52 a.m.
On 2014-Nov-23, at 5:46 PM, Pete Turnbull wrote:
On 23/11/2014 22:12, Brent Hilpert wrote:
Well, I'm willing to entertain counter-intuitive notions but I'm really not
convinced.
Some reading suggests going beyond the current level at which one loses intentional muscle
control, while it will or can result in involuntary muscle contractions, those
contractions may be more likely to result in hanging on rather than getting kicked off,
and you're more likely to exceed that current level with the higher voltage.
Getting 'thrown off' also has it's own set of associated risks.
But isn't there an internal logic problem in there to begin with? I thought the point
of the step-down/isolation transformer for portable tools was to reduce the 240V to a
safer level (or is just to make it easier for manufacturers, to only have to manufacture
110/120V tools worldwide?, in which case one would think the onus would be on NA to
change). Those transformers aren't required in NA because we're only operating at
120V.
Once you require the transformers to get down from 240V, you might as well go to the
center-tapped 55-0-55 technique at a small increase in complexity over 0-110 for a further
safety improvement.
The benefit of the North American split-phase
system vs EU/Britain is
you have the energy & copper-efficiency of 240V available for heavy
appliances, but you have the safety factor throughout the house of
never having more than 120V between you and earth.
That's not as much of a safety factor as many people think, indeed possibly not at
all. It's true that 230V will give you more of a jolt than 120V, and more so because
human body resistance drops slightly at higher voltages. Nevertheless, there's a
strong argument that a 230V jolt is more likely to throw you off the conductor whereas
120V may be more likely to make you latch onto it. It depends how you touch it,
obviously, but evidence suggests that (EHT excepted) the region around 100V-130V is about
the most dangerous. I recall reading a discussion of that as part of the European
harmonisation of voltages, in connection with 110V for site equipment. Evidently that was
in part why the idea of one live and one neutral with a single simple MCB or RCD was
rejected in favour of the split 55-0-55 system (proposed by the UK).
9:29 a.m.
Brent Hilpert wrote:
[..]
Once you require the transformers to get down from
240V, you might as well go to the center-tapped 55-0-55 technique at a small increase in
complexity over 0-110 for a further safety improvement.
If you would ask me if I would change the usual german installations
against the "higher security" of the NA system you would hear an
No thanks" for sure...
I know of no other country in the world where Plugs are so secure that they
disconnect them selves from the outlet by simply falling out...
Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
9:44 a.m.
----- Original Message -----
From: "Holm Tiffe" <holm at freibergnet.de>
To: <cctalk at classiccmp.org>
Sent: Monday, November 24, 2014 12:29 PM
Subject: Re: Who's rewired their house for this hobby?
If you would ask me if I would change the usual german
installations
against the "higher security" of the NA system you would hear an
No thanks" for sure...
I know of no other country in the world where Plugs are so secure that
they
disconnect them selves from the outlet by simply falling out...
-----------------
You mean yours remain connected when they fall out?
;-)
9:57 a.m.
I know of no
other country in the world where Plugs are so secure that
they disconnect them selves from the outlet by simply falling out...
----------------- You mean yours remain connected when they fall out?
;-)
Wouldn't that require a lower frequency and/or higher voltage?
Besides, it's a "feature"
If you're doing something unsafe, such as using power tools with an
extension cord, it periodically forces you to recheck all of the
connections.
I'm having some fun tree pruning with 12V Nextec and Ridgid, and 40V
Ryobi.
1:48 p.m.
On 2014-Nov-24, at 9:29 AM, Holm Tiffe wrote:
Brent Hilpert wrote:
[..]
Funny, I've never had a plug fall out of it's own accord.
There is a certain benefit, when somebody trips over a tool cord or the vacuum cleaner is
pulled to the cord limit, to having the plug release, than to having the plug dutifully
stay in the receptacle and strain the cord or rip it off the appliance or the plug
instead.
I will point out my initial entry in this discussion was "all these systems have
varying benefits and detriments", and "present varying tradeoffs". You can
poke holes in any of them or say it would be better done this way or that way.
Once you require the transformers to get down
from 240V, you might as well go to the center-tapped 55-0-55 technique at a small increase
in complexity over 0-110 for a further safety improvement.
If you would ask me if I would change the usual german installations
against the "higher security" of the NA system you would hear an
No thanks" for sure...
I know of no other country in the world where Plugs are so secure that they
disconnect them selves from the outlet by simply falling out... From over here, the 240V, 3-phase into the house,
plethora of different plugs (I take it that situation has been improving over the years),
transformers required for common power tools, ring circuits, etc, etc. of the EU, etc. can
seem arcane and bizarre, but then it's very much what one is familiar with.
Don't worry, I have my own gripes about the NA system, like the stupid little wall
outlet and switch boxes, with an incompetently-designed mounting methodology, that
you're supposed to stuff all the wires and connections and devices into.
2:06 p.m.
On 2014-Nov-24, at 1:48 PM, Brent Hilpert wrote:
On 2014-Nov-24, at 9:29 AM, Holm Tiffe wrote:
Talk about annoying mail program behaviour (Mac Mail), anytime one begins a sentence with
the word "From" the mail program takes it as part of the message being replied
to and quotes it. The above paragraph was from me and should not have been quoted.
Brent Hilpert wrote:
[..]
Funny, I've never had a plug fall out of it's own accord.
There is a certain benefit, when somebody trips over a tool cord or the vacuum cleaner is
pulled to the cord limit, to having the plug release, than to having the plug dutifully
stay in the receptacle and strain the cord or rip it off the appliance or the plug
instead.
I will point out my initial entry in this discussion was "all these systems have
varying benefits and detriments", and "present varying tradeoffs". You can
poke holes in any of them or say it would be better done this way or that way.
> From over here, the 240V, 3-phase into the house, plethora of different plugs (I take
it that situation has been improving over the years), transformers required for common
power tools, ring circuits, etc, etc. of the EU, etc. can seem arcane and bizarre, but
then it's very much what one is familiar with. Once you require the transformers to get down
from 240V, you might as well go to the center-tapped 55-0-55 technique at a small increase
in complexity over 0-110 for a further safety improvement.
If you would ask me if I would change the usual german installations
against the "higher security" of the NA system you would hear an
No thanks" for sure...
I know of no other country in the world where Plugs are so secure that they
disconnect them selves from the outlet by simply falling out... Don't worry, I have my own gripes about the NA
system, like the stupid little wall outlet and switch boxes, with an
incompetently-designed mounting methodology, that you're supposed to stuff all the
wires and connections and devices into.
26 Nov
26 Nov
11:11 p.m.
On Mon, 24 Nov 2014, Brent Hilpert wrote:
On 2014-Nov-24, at 9:29 AM, Holm Tiffe wrote:
I've noticed a lot of AC sockets in airports are so worn that sometimes
you need tape to keep plugs plugged in.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
Brent Hilpert wrote:
[..]
Funny, I've never had a plug fall out of it's own accord. Once you require the transformers to get down
from 240V, you might as well go to the center-tapped 55-0-55 technique at a small increase
in complexity over 0-110 for a further safety improvement.
If you would ask me if I would change the usual german installations
against the "higher security" of the NA system you would hear an
No thanks" for sure...
I know of no other country in the world where Plugs are so secure that they
disconnect them selves from the outlet by simply falling out...
24 Nov
24 Nov
6:03 p.m.
On 24/11/2014 08:52, Brent Hilpert wrote:
Well, I'm willing to entertain counter-intuitive
notions but I'm
really not convinced. Some reading suggests going beyond the current
level at which one loses intentional muscle control, while it will or
can result in involuntary muscle contractions, those contractions may
be more likely to result in hanging on rather than getting kicked
off, and you're more likely to exceed that current level with the
higher voltage. Getting 'thrown off' also has it's own set of
associated risks.
I was just reporting what I read, which came from one of the members of
the committee that made the decisions - after much "discussion",
apparently. To be honest, I doubt there's much difference, and
certainly any voltage in those regions can be fatal. In fact, much
lower voltages can be fatal, if applied to broken skin such that current
passes across (actually, through) your chest. That's why there's such a
category as SELV. Yet I remember once getting a very painful shock from
a 9V PP3 battery when a couple of terminals went through my skin, but
fortunately only across one hand.
But isn't there an internal logic problem in there
to begin with? I
thought the point of the step-down/isolation transformer for portable
tools was to reduce the 240V to a safer level (or is just to make it
easier for manufacturers, to only have to manufacture 110/120V tools
worldwide?
Not really, the point is to reduce the maximum to *50V* above ground,
which is below the 90V (?) "safe" threshold.
in which case one would think the onus would be on NA to
change). Those transformers aren't required in NA
because we're only
operating at 120V. Once you require the transformers to get down from
240V, you might as well go to the center-tapped 55-0-55 technique at
a small increase in complexity over 0-110 for a further safety
improvement.
As the EU requires.
--
Pete
6:21 p.m.
Getting 'thrown off' also has it's own set
of associated risks.
"Getting thrown off" is pretty much where a most injuries occur.
Common injuries are falling off ladders, dropping or jabbing a held
tool, or slamming a limb into something sharp in reaction to the
shock. Or, in some case, throwing a tool or fist and hitting someone
else.
It is really pretty difficult to kill yourself with 120 V AC. It is
actually pretty difficult to even get mildly injured with 120 V AC. If
you anticipate the shock, 120 V AC does not even really hurt much -
just an intense sensation. More than a few electricians will test a
household wire simply by feeling it.
Obviously, here are cases where 120 V AC can be fatal - wet body, poor
heart, and so on - but those cases are in a tiny minority.
--
Will
25 Nov
25 Nov
12:56 p.m.
"Getting thrown off" is pretty much where a
most injuries occur.
Common injuries are falling off ladders, dropping or jabbing a held
tool, or slamming a limb into something sharp in reaction to the
shock. Or, in some case, throwing a tool or fist and hitting someone
else.
IMHO this is also the main hazard from the stored charge in CRTs.
Although the voltage is high, there is not enough charge/energy to
kill you (if you have a heart problem, that's another matter, of course).
But the shock from said charge is enough to make you jerk, and maybe
either break the glass of the CRT (by hitting it with the tool you are
holding, say) or drop the CRT.
-tony
24 Nov
24 Nov
5:39 a.m.
On Sun, Nov 23, 2014 at 02:12:15PM -0800, Brent Hilpert wrote:
[...]
The ring system in Britain with fuses in the plugs
provides a safety factor
of appropriately limited current at the wall. On the other hand, in NA the
vast majority of in-wall house wiring is done with #14 wire(15A circuits),
which is a lot easier to work than whichever gauge Britain uses for 25A or
32A circuits.
Actually, we use the same gauge, except it's in metric :) Or to give actual
figures, 32A ring circuits typically use 2.5mm^2 cable, whereas #14 is
approximately 2.1mm^2. It's stiffer than 13A mains flex, but easy enough to
work with.
The ring circuit provides two paths back to the fuse box, so the whole circuit
can in theory carry twice the current. In practice, of course, the paths don't
have equal resistance so the current will not be shared equally. This
especially applies when one path has infinite resistance due to some muppet
cocking up the installation, as a quick continuity test won't detect it.
The benefit of the North American split-phase system
vs EU/Britain
Point of order: The UK is part of the EU; and 230V is not pecular to the EU but
standard across the world with the notable exceptions of North America and
Japan. Japan is also very much the poster child of how not to design an
electricity distribution network.
is you have the energy & copper-efficiency of 240V
available for heavy
appliances, but you have the safety factor throughout the house of never
having more than 120V between you and earth.
We have the safety factor of not using those lethal NEMA plugs that expose the
user to 120V in the first place.
1:48 p.m.
On 2014-Nov-24, at 5:39 AM, Peter Corlett wrote:
Yes, tepidly it sometimes seems from watching from a distance, (and except for the Euro).
They were just getting discussed with some distinctions in the course of the thread.
On Sun, Nov 23, 2014 at 02:12:15PM -0800, Brent
Hilpert wrote:
[...]
Right, I was forgetting about the ring part and just looking at the current part (a 32A
circuit in NA would require at least #10 wire (5.26 mm^2)), although it's interesting
that size gauge is allowed even in light of the ring.
But then you have to form the ring which is it's own expense, so in terms of my
original point of varying tradeoffs it's just a different tradeoff.)
The ring system in Britain with fuses in the
plugs provides a safety factor
of appropriately limited current at the wall. On the other hand, in NA the
vast majority of in-wall house wiring is done with #14 wire(15A circuits),
which is a lot easier to work than whichever gauge Britain uses for 25A or
32A circuits.
Actually, we use the same gauge, except it's in metric :) Or to give actual
figures, 32A ring circuits typically use 2.5mm^2 cable, whereas #14 is
approximately 2.1mm^2. It's stiffer than 13A mains flex, but easy enough to
work with.
The ring circuit provides two paths back to the fuse box, so the whole circuit
can in theory carry twice the current. In practice, of course, the paths don't
have equal resistance so the current will not be shared equally. This
especially applies when one path has infinite resistance due to some muppet
cocking up the installation, as a quick continuity test won't detect it. The benefit of
the North American split-phase system vs EU/Britain
Point of order: The UK is part of the EU; 
23 Nov
23 Nov
2:44 p.m.
On 11/23/2014 01:15 PM, Holm Tiffe wrote:
.
but sine you already have 240V outlets, it should be
possible to change the
distribution slowly to 3 phase power.. it's a matter of time and the only
needed thing for compatibility are the transformers with modified
secondaries.
"Low hanging fruit".
Most commercial office and retail buildings already have 3-phase
supplies because of installed HVAC electrical needs. I wouldn't mind
that--the heat pump on my house has to have the compressor and fan motor
capacitors checked annually because they do degrade with time. I just
replaced the 135 uF 330VAC start capacitor on the compressor--it has two
capacitors; a 135-160 uF start and a 40 uF run as well as a starting
relay--modern Chinese capacitors do not deliver the life that old
PCB-containing oil ones did. If the compressor instead used a 3-phase
motor, none of that would be necessary. The last starting cap simply
blew its top, even though it's a vented unit and only 3 years old.
But if you'd ask any utilities manager why not move to 3-phase
residential distribution, you'd get the response that residential
distribution was, in fact, 3 phase--one phase per household.
To answer Tony's question about power tools, almost all hand/portable
power tools are rated for 15A or less. My router (Bosch, if it
matters), claims a rating of 3 hp and maximum current of 15A at 120V.
Yes, I know that 3 hp is about 2200W and therefore almost 19A at 120V.
Such is the nonsense that goes for nameplate ratings in the US. Vacuum
cleaners are rated at the motor's "locked rotor" current draw, as
another example.
Large power tools, such as a floor sander or table saw are often 240V
units, meaning special wiring and outlets.
Wasn't the UK slow to standardize on receptacles and plugs? I seem to
recall a mention that some appliances long ago were supplied without
plugs altogether; the customer was supposed to install whatever was
suitable.
--Chuck
3:12 p.m.
But if you'd ask any utilities manager why not
move to 3-phase
residential distribution, you'd get the response that residential
distribution was, in fact, 3 phase--one phase per household.
Over here that is often the case. The distribution cable is 3 phase and
different houses along the road get one of the phases brought in. For
some reason (read : because they can get away with it), having all 3
phases brought into one house is difficult to get and expensive.
To answer Tony's question about power tools,
almost all hand/portable
power tools are rated for 15A or less. My router (Bosch, if it
matters), claims a rating of 3 hp and maximum current of 15A at 120V.
Over here, a motor rating in W refers to the electical input power, one in hp
to the mechanical output power. At least from reputable companies.
Yes, I know that 3 hp is about 2200W and therefore
almost 19A at 120V.
Such is the nonsense that goes for nameplate ratings in the US. Vacuum
cleaners are rated at the motor's "locked rotor" current draw, as
another example.
I guess the ratings of audio power amplifiers is another. I am still wondering
why the world has an energy problem given I can get a 360W PC speaker system
that runs off a 12V 1A PSU.
Wasn't the UK slow to standardize on receptacles
and plugs? I seem to
Strictly it still hasn't. While you are very likely to find the BS1363 13A socket
outlet just about everywhere, the BS546 round pin sockets are still allowed
even on new wiring (AFAIK, they certainly were a few years ago). And there
are other permitted sockets too.
recall a mention that some appliances long ago were
supplied without
plugs altogether; the customer was supposed to install whatever was
suitable.
Yes. Now it is a legal requirement that portable equiment is supplied with a
fitted BS1363 plug. I am sure there are exceptions, e.g. for 110V power tools,
etc. In many ways I wish things still came with no plug. It would mean I wouldn't
have to cut off the possibly dangerous moulded plug first...
In the 1950s/1960s all sorts of plugs were common over here. Repair workshops for
radios, etc, often had an array of different mains sockets at each bench. Of course there
were also 'suicide leads' (mains plug to croc clips) which you hid from the safety
inspector.
Field service engineers (for domestic TVs, kichen appliances, etc) would have a problem
plugging in their soldering iron, etc. There were a variety of universal plugs made, some
safer than others.
I bought a second-hand slide projector over here and it came with about 10 mains leads
ending in assorted main plugs 2 and 3 pin, even a bayonet lampholder plug. The old owner
had
used it for illustrating his lectures and he never knew what socket he would find in the
lecture hall...
-tony
--Chuck
3:49 p.m.
On 11/23/2014 03:12 PM, tony duell wrote:
I bought a second-hand slide projector over here and
it came with about 10 mains leads
ending in assorted main plugs 2 and 3 pin, even a bayonet lampholder plug. The old owner
had
used it for illustrating his lectures and he never knew what socket he would find in the
lecture hall...
Many in the construction trades use portable tools with Hubbell
"twist-lock" (NEMA "L") plugs. I don't know why those never made
it
into the consumer market. A leaf blower with the standard 2-blade plug
will pull out of the socket on an extension cord in a heartbeat.
I believe the two-blade NEMA 1-15 plug originated with Hubbell,
strangely enough.
--Chuck
24 Nov
24 Nov
10:12 a.m.
On 11/23/2014 03:15 PM, Holm Tiffe wrote:
but sine you already have 240V outlets, it should be
possible to change the distribution slowly to 3 phase
power.. it's a matter of time and the only needed thing
for compatibility are the transformers with modified
secondaries. I don't think that this would ever happen
since the US is the biggest US of the world and other
people are just dumb aliens, aren't they? :-) But with
that stone age power system you are stumbling over your
own feet all the time.. Regards, Holm
Well, we only have single phase 7200 V
running down our
street. This 7200 V run goes a LONG way,
so an entire region that may be about a mile square is
running off a single phase HV line, that
branches over and over again into the neighborhood. Many of
these feeds that go back
into subdivisions are buried, and have pad-mount
transformers placed every few homes.
Our house has a pole-mount 50 KVA transformer that supplies
just our one house, although
that is kind of an accident of the layout. We are on the
corner lot, and otherwise probably
would have shared that transformer with a neighbor. Our LV
drop is buried.
So, what I'm saying here is there is a lot of high-cost
infrastructure that would have to be
ripped up (literally out of the ground) to go to 3 phase
into the homes. Not to mention
all the meters, service entry gear and breaker panels.
I have a small machine shop in my basement, and some years
ago it seemed like 3-phase
would be real nice for that. Now that VFDs can run 3-phase
motors so nicely off single
phase power, it is no longer of much interest.
Unless you desire to run a Cray 1 in your home (yeah, keep
dreaming) there really isn't
that much need for 3-phase power. Most machines that
"require" 3-phase can actually
be rewired internally to run off single-phase. One I can
think of that won't is the
KL-10B, which had a totally insane power system starting
with a 3-phase transformer
and rectifier. A mid-scale 370 like the 145 had a
motor-generator set, which could be
run off a large VFD. Or, replace the stupid MG and 415 Hz
power supplies with
off-the-shelf large power supplies running off single-phase
240 V.
Jon
12:28 p.m.
On 2014-11-24 10:12, Jon Elson wrote:
On 11/23/2014 03:15 PM, Holm Tiffe wrote:
Stuff I know need 3-phase:
VAX 86x0 machines. They have 3-phase motors for the fans. (Don't wire
things up backwards, or your airflow will run backwards, which is not good.)
RP06 disk drives. They use 2 phases for their motors.
I wasn't aware that the KL needs 3-phase, but it might just be that the
power supplies are large enough, and complicated enough, that you can't
just rewire them.
Johnny
but sine you already have 240V outlets, it should
be possible to
change the distribution slowly to 3 phase power.. it's a matter of
time and the only needed thing for compatibility are the transformers
with modified secondaries. I don't think that this would ever happen
since the US is the biggest US of the world and other people are just
dumb aliens, aren't they? :-) But with that stone age power system you
are stumbling over your own feet all the time.. Regards, Holm
Well, we only have
single phase 7200 V running down our street. This
7200 V run goes a LONG way,
so an entire region that may be about a mile square is running off a
single phase HV line, that
branches over and over again into the neighborhood. Many of these feeds
that go back
into subdivisions are buried, and have pad-mount transformers placed
every few homes.
Our house has a pole-mount 50 KVA transformer that supplies just our one
house, although
that is kind of an accident of the layout. We are on the corner lot,
and otherwise probably
would have shared that transformer with a neighbor. Our LV drop is buried.
So, what I'm saying here is there is a lot of high-cost infrastructure
that would have to be
ripped up (literally out of the ground) to go to 3 phase into the
homes. Not to mention
all the meters, service entry gear and breaker panels.
I have a small machine shop in my basement, and some years ago it seemed
like 3-phase
would be real nice for that. Now that VFDs can run 3-phase motors so
nicely off single
phase power, it is no longer of much interest.
Unless you desire to run a Cray 1 in your home (yeah, keep dreaming)
there really isn't
that much need for 3-phase power. Most machines that "require" 3-phase
can actually
be rewired internally to run off single-phase. One I can think of that
won't is the
KL-10B, which had a totally insane power system starting with a 3-phase
transformer
and rectifier. A mid-scale 370 like the 145 had a motor-generator set,
which could be
run off a large VFD. Or, replace the stupid MG and 415 Hz power
supplies with
off-the-shelf large power supplies running off single-phase 240 V.
1:11 p.m.
Just to feed the flames, here are some interesting statistics (2011)
concerning electrical safety:
UK:
Total number of households: 26.4 million
Total number of household fires due to electric issues: 20400
US:
Total number of households: 115 million
Total number of household fires due to electric issues: 47700
WTF, UK?
(watch for wrap!)
Refs:
http://www.electricalsafetyfirst.org.uk/news-and-campaigns/policies-and-res…
http://www.nfpa.org/research/reports-and-statistics/fire-causes/electrical
http://www.ons.gov.uk/ons/rel/census/2011-census/population-estimates-by-fi…
http://quickfacts.census.gov/qfd/states/00000.html
--
Will
1:13 p.m.
isn?t the UK also known for the Highest amount of violent crimes as well?
On Nov 24, 2014, at 4:11 PM, William Donzelli <wdonzelli at gmail.com> wrote:
Just to feed the flames, here are some interesting
statistics (2011)
concerning electrical safety:
UK:
Total number of households: 26.4 million
Total number of household fires due to electric issues: 20400
US:
Total number of households: 115 million
Total number of household fires due to electric issues: 47700
WTF, UK?
(watch for wrap!)
Refs:
http://www.electricalsafetyfirst.org.uk/news-and-campaigns/policies-and-res…
http://www.nfpa.org/research/reports-and-statistics/fire-causes/electrical
http://www.ons.gov.uk/ons/rel/census/2011-census/population-estimates-by-fi…
http://quickfacts.census.gov/qfd/states/00000.html
--
Will
1:17 p.m.
Just a guess, but the UK by and large is much colder than the US but generally not
severely cold anywhere. That might result in a) higher use of heating, and b) higher use
of electrical heating when heating is present.
Jim
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of William Donzelli
Sent: November-24-14 3:12 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Who's rewired their house for this hobby?
Just to feed the flames, here are some interesting statistics (2011) concerning electrical
safety:
UK:
Total number of households: 26.4 million Total number of household fires due to electric
issues: 20400
US:
Total number of households: 115 million
Total number of household fires due to electric issues: 47700
WTF, UK?
6:55 p.m.
On Mon, Nov 24, 2014 at 04:11:45PM -0500, William Donzelli wrote:
Just to feed the flames, here are some interesting
statistics (2011)
concerning electrical safety:
UK:
Total number of households: 26.4 million
Total number of household fires due to electric issues: 20400
US:
Total number of households: 115 million
Total number of household fires due to electric issues: 47700
WTF, UK?
(watch for wrap!)
Refs:
http://www.electricalsafetyfirst.org.uk/news-and-campaigns/policies-and-res…
http://www.nfpa.org/research/reports-and-statistics/fire-causes/electrical
An amusing comparison, but the reports are clearly not measuring the same
thing.
The UK fires count fires that involved electrical appliances, which does not
necessarily mean it was down to an electrical fault. Most of the 20,403 fires
are "misuse" (10,735 fires) of "cooking appliances" (11,954 fires). I
suspect
these are mainly of the "forgot the grill was on" kind, and would continue to
occur even if the properties didn't have electricity at all! The odds of dying
if one has such a fire is 0.22% which are pretty good odds. The injury rate is
12% but it's not defined what an injury is.
I suspect this mainly comes from emergency services figures: the fire brigade
being called out to wake up a drunkard whose kitchen is full of smoke counts as
a "fire", and a subsequent trip to A&E for a check-up for smoke inhalation
and
to bandage minor burns counts as an "injury".
There were "21,300 reported U.S. non-confined home structure fires involving
electrical distribution or lighting equipment resulted in 295 civilian deaths"
i.e. a 14% risk of death from the fire. These are clearly more major
incidents, directly caused by dodgy wiring or other dangerous electrical work.
For the UK, the page contradicts itself in claiming eight deaths due to
"Installations" but ten due to "Electricity supply - Wiring, cabling,
plugs".
That is some four or five times less lethal per capita than the USA.
Fires and electrocutions are caused by *current*, and the voltage is very much
a red herring. America should be treating its 110V supplies with the same
respect the rest of the world gives to 220V, and not just half-jobbing it due
to myths about the lower voltage being inherently safer.
7:18 p.m.
Fires and electrocutions are caused by *current*, and
the voltage is very much
a red herring. America should be treating its 110V supplies with the same
respect the rest of the world gives to 220V, and not just half-jobbing it due
to myths about the lower voltage being inherently safer.
Or that myth about "lethal" plugs here in the US. Yes, tens of
thousands of people die every year to those damn things.
One thing - why do UK people get so butthurt when it comes to US vs.
UK electric systems? Generally, US electricians just do not care about
how things are done in the UK. Both of the damn things work if you
follow the rules, and they mostly work even when you do not.
Right now, I am installing a light and a couple of outlet, and I
suppose I moved another, larger box - and guess what? It is going to
work just fine. No fires will be set. And I might just touch the wires
on purpose. Stay tuned for the obituary.
--
Will
7:54 p.m.
On 2014-Nov-24, at 6:55 PM, Peter Corlett wrote:
On Mon, Nov 24, 2014 at 04:11:45PM -0500, William
Donzelli wrote:
...
> Refs:
>
http://www.electricalsafetyfirst.org.uk/news-and-campaigns/policies-and-res…
> http://www.nfpa.org/research/reports-and-statistics/fire-causes/electrical
...
For the UK, the page contradicts itself in claiming
eight deaths due to
"Installations" but ten due to "Electricity supply - Wiring, cabling,
plugs".
That is some four or five times less lethal per capita than the USA.
I earlier tried looking up some empirical stats but (as expected) concluded that
wasn't likely to be helpful, there are too many variables, including social and legal
issues, to easily conclude a relation to voltage. For example, in my jurisdiction one is
still allowed to wire one's own house, regardless of ability, which could skew
accident stats negatively compared to a jurisdiction where only 'professionals'
are allowed to touch any part of the installed electrical (I don't know what the rules
are in the EU).
Fires and electrocutions are caused by *current*, and
the voltage is very much
a red herring. America should be treating its 110V supplies with the same
respect the rest of the world gives to 220V, and not just half-jobbing it due
to myths about the lower voltage being inherently safer.
Fires are caused by power not current; but you're right, there's plenty of power
at the end of both
a typical 120V circuit and 240V circuit to start a fire. As such, electrical fire risk is
treated seriously on both sides of the pond.
But I would quite suggest that the electrocution/shock-injury risk relation - based on
the known physics & biology - between 12V, 120V, 240V, and 600V is an increasing and
non-linear one. Trying to deny or toss off the difference in the 120-240V region as
inconsequential just looks like an attempt at rationalisation.
25 Nov
25 Nov
4:55 a.m.
William Donzelli wrote:
Just to feed the flames, here are some interesting
statistics (2011)
concerning electrical safety:
UK:
Total number of households: 26.4 million
Total number of household fires due to electric issues: 20400
US:
Total number of households: 115 million
Total number of household fires due to electric issues: 47700
WTF, UK?
[..]
--
Will
Will... a german saying is "not all things that limp are an comparsion"
don't know it this is tranlateable at all..
Does it really matter how many people get killed trough electricity?
If it matters how many people are getting killed, why the USA have that
sick wepon laws at all? Why are the lawers there still allowed to kill
people? How about policeman and their self-defence rights? (Ferguson).
You shouldn't really think about the lethality for 230 Volts at the first
place...
BTW please show german numbers.. The UK != EU and Germany != EU and
US != 1/EU or so..
Kind Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
6:49 a.m.
Does it really matter how many people get killed
trough electricity?
If it matters how many people are getting killed, why the USA have that
sick wepon laws at all? Why are the lawers there still allowed to kill
people? How about policeman and their self-defence rights? (Ferguson).
Yeah...I am not going to touch this can of worms. Move on.
BTW please show german numbers..
I did not have them handy, and did not want to put to much effort into
such simple analysis.
--
Will
9:28 a.m.
William Donzelli wrote:
:-) Don't tought that anyway..
keep smiling,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
Does it really
matter how many people get killed trough electricity?
If it matters how many people are getting killed, why the USA have that
sick wepon laws at all? Why are the lawers there still allowed to kill
people? How about policeman and their self-defence rights? (Ferguson).
Yeah...I am not going to touch this can of worms. Move on. BTW please show german numbers..
I did not have them handy, and did not want to put to much effort into
such simple analysis.
--
Will 
24 Nov
24 Nov
1:20 p.m.
On Nov 24, 2014, at 12:28 PM, Johnny Billquist <bqt
at update.uu.se> wrote:
Stuff I know need 3-phase:
VAX 86x0 machines. They have 3-phase motors for the fans. (Don't wire things up
backwards, or your airflow will run backwards, which is not good.)
RP06 disk drives. They use 2 phases for their motors.
I wasn't aware that the KL needs 3-phase, but it might just be that the power
supplies are large enough, and complicated enough, that you can't just rewire them.
The main DC supply for the KL CPU requires 3-phase. It uses a ferro-resonant transformer
and that requires 3-phase. There are also a number of 3-phase fans.
Since I don't have 3-phase at my shop, I'm planning on re-doing my KL's power
supplies to be modern switchers run off of 240v (to keep the current draw lower). That
and replacing the 3-phase fans should allow me to run my KL from 240v.
7:46 p.m.
On 11/24/2014 02:28 PM, Johnny Billquist wrote:
I wasn't aware that the KL needs 3-phase, but it might
just be that the power supplies are large enough, and
complicated enough, that you can't just rewire them.
The KL10B had an immense 3-phase transformer, star rectifier
and capacitor
bank, which produced about 12 V DC. This was fed to a
massive linear regulator
on a huge round heat sink. Compuserve ran a LOT of KL10B's,
and designed their
own switching power supplies to save power and air
conditioning costs. They never
got DEC to pick up on that, so had to retrofit all the
machines as they came in.
Jon
9:13 p.m.
On 2014-11-24 19:46, Jon Elson wrote:
On 11/24/2014 02:28 PM, Johnny Billquist wrote:
That it is huge and linear I know. I have actually replaced that
fricking thing in a KL10. It was no fun. It is seriously heavy, for
obvious reasons. (Although it's only the power for the memory system
that is this heavy linear thing, unless I remember wrong.)
What I wasn't aware of was that the power supply system actually
depended on/needed 3-phase power, as opposed to just, say, grabbing the
power between two phases (ie. getting 400V for Europe), or just use each
phase separately, but use all of them to reduce the load on individual
supplies.
Johnny
I wasn't aware that the KL needs 3-phase, but it might just be that
the power supplies are large enough, and complicated enough, that you
can't just rewire them.
The KL10B had an immense 3-phase transformer, star rectifier and capacitor
bank, which produced about 12 V DC. This was fed to a massive linear
regulator
on a huge round heat sink. Compuserve ran a LOT of KL10B's, and
designed their
own switching power supplies to save power and air conditioning costs.
They never
got DEC to pick up on that, so had to retrofit all the machines as they
came in. 
25 Nov
25 Nov
12:18 p.m.
On Mon, Nov 24, 2014 at 8:46 PM, Jon Elson <elson at pico-systems.com> wrote:
The KL10B had an immense 3-phase transformer, star
rectifier and capacitor
bank,
About 3.9F worth of capacitors, which was a heck of a lot back in the mid 1970s.
which produced about 12 V DC. This was fed to a
massive linear
regulator on a huge round heat sink.
Actually to 13 massive linear regulators on multiple large heat sinks.
Compuserve ran a LOT of KL10B's, and designed
their own switching power supplies to save power and air conditioning costs. They
never got DEC to pick up on that, so had to retrofit all the machines as they came
in.
When the KL10 was designed, DEC was already using switching power
supplies in some machines (e.g., PDP-11/40, /45, /55, /70). However,
the load regulation, ripple, and noise specs weren't great, and ECL is
sensitive to the ripple and noise. By the time Compuserve designed
their replacement, switching power supply technology had improved
somewhat.
12:25 p.m.
However,
the load regulation, ripple, and noise specs weren't great, and ECL is
sensitive to the ripple and noise.
On the other hand, ECL does not suffer from the spikes, burps and
farts TTL tends to make.
Late model Cybers tend to have very little in the way of filtering,
simply because the ECL load is "nice".
--
Will
12:58 p.m.
On 11/25/2014 12:25 PM, William Donzelli wrote:
400Hz 3-phase power also helps. That gives a ripple frequency of 2400Hz
in a fullwave "star" configuration, with only 13% ripple, no? The same
holds for early model Cybers (even before they were called "Cyber")
which used a different variety of logic.
--Chuck
However,
the load regulation, ripple, and noise specs weren't great, and ECL is
sensitive to the ripple and noise.
On the other hand, ECL does not suffer from the spikes, burps and
farts TTL tends to make.
Late model Cybers tend to have very little in the way of filtering,
simply because the ECL load is "nice".
1:02 p.m.
400Hz 3-phase power also helps. That gives a ripple
frequency of 2400Hz in
a fullwave "star" configuration, with only 13% ripple, no? The same holds
for early model Cybers (even before they were called "Cyber") which used a
different variety of logic.
Well, yes, of course. Which leads to the question why DEC did not go
that route. I guess the KL10 power supply people were drunk (again).
--
Will
1:17 p.m.
On Tue, Nov 25, 2014 at 2:02 PM, William Donzelli <wdonzelli at gmail.com> wrote:
Well, yes, of course. Which leads to the question why
DEC did not go
that route. I guess the KL10 power supply people were drunk (again).
Last year I went to lunch with a friend, and he introduced me to one of his
friends, who had worked for DEC for a long time. We got to talking about
various DEC machines, and I mentioned that I was surprised about an
aspect of the KL10 design. To my astonishment, he replied, "The reason
I made that decision was..."
He probably wasn't involved in the ECL power supply design, but next time
I see him I'll ask.
I have heard from multiple sources that DEC made it a point never to design
machines that actually needed a "machine room". Even the KL10-based
systems and the VAX 9000 were intended to be usable in an ordinary office,
though that was rarely done in practice. Perhaps the use of 400 Hz power was
considered to make that significantly less practical.
6:58 p.m.
On 11/25/2014 03:17 PM, Eric Smith wrote:
On Tue, Nov 25, 2014 at 2:02 PM, William Donzelli
<wdonzelli at gmail.com> wrote:
I'd love to know the story, if he does know it!
Well, yes, of course. Which leads to the question
why DEC did not go
that route. I guess the KL10 power supply people were drunk (again).
Last year I
went to lunch with a friend, and he introduced me to one of his
friends, who had worked for DEC for a long time. We got to talking about
various DEC machines, and I mentioned that I was surprised about an
aspect of the KL10 design. To my astonishment, he replied, "The reason
I made that decision was..."
He probably wasn't involved in the ECL power supply design, but next time
I see him I'll ask.
I have heard from multiple sources that DEC made it a point never to design
machines that actually needed a "machine room". Even the KL10-based
systems and the VAX 9000 were intended to be usable in an ordinary office,
though that was rarely done in practice. Perhaps the use of 400 Hz power was
considered to make that significantly less practical.
Well, many machines by many makers didn't actually NEED a
"machine room". On the other hand,
the power dissipation and fan noise of the KL10B was QUITE
considerable! And, the noise and
massive jets of air from the back of a VAX 11/780 were also
not quite consistent with an
office environment. I know (the hard way) that a VAX will
run in 90 degree F air for a very
long time. I think we got our up to 130 F once when the AC
crapped out on a weekend.
The VAX was in the home of the former KL10B with a
trouble-prone Liebert cooler.
We had a thermostat wired into the emergency power off
button on the wall and set it to
dump the power at 90 F. Often we'd run in, notice the AC
was down, shove the thermostat
as high as it would go and try to restart the AC system, and
then do an orderly shutdown
if the AC couldn't be brought back online.
This machine room was kept quite clean by the AC, which was
good for the disk drives.
Oh, many of the larger machines, such as KL10's and
early/big VAXen needed the raised
flooring for the cables, which would become a HUGE mess
without. The VAX 780 was
nice as all the "main box" cabling was internal, but if you
had massbus drives, you
ended up with big snakes running all over.
Jon
26 Nov
26 Nov
12:05 a.m.
On 11/25/2014 6:58 PM, Jon Elson wrote:
Well, many machines by many makers didn't actually
NEED a "machine
room". On the other hand,
the power dissipation and fan noise of the KL10B was QUITE considerable!
A company
I consulted for bought a technology for full automation and
remote management of data centers, which was developed in Japan.
they wanted to reduce power, and took a pretty radical approach. The
system we got had full weather sensing for rain, heat, humidity wind,
etc., and would actually shut down machine room AC as possible and open
the room to outdoor circulation. Also integrated access control and
intrusion alarms.
They also had a very nice remote serial console package and a lot of
patents, and that was why the precursor company we had bought the rights
in the US. I think the environmental stuff was split off to another
company, but we had the remote console control. We could see the serial
from any server, and do some resets, etc., to control
any server.
But they saved quite a lot by studying where to put these centers where
they could use a lot less power.
The product is still available if anyone is interested, and is handy to
use for my systems.
oh, unfortunately it won't be free, sorry.
thanks
jim
25 Nov
25 Nov
6:49 p.m.
On 11/25/2014 03:02 PM, William Donzelli wrote:
IBM 360's used 2500 Hz single-phase power produced
internally by a
converter-inverter unit. it made the individual power
supply modules QUITE
small. The problem is they had totally minimal energy
storage in the DC
link of the converter-inverter unit, so the machines were
extremely sensitive to
the slightest power bobble on the incoming 208 V 3-phase 60
Hz power. The
SLIGHTEST flicker seen on a fluorescent light meant the 360
crashed.
The 370's went to 415 Hz provided by an internally-mounted
motor-generator
set, this made the machines able to ride through significant
power dropouts.
At least, the KL10B power supply DID work reliably. Our
university didn't
care about the power waste, but obviously it was a big
problem for
Compuserve.
Jon
400Hz 3-phase
power also helps. That gives a ripple frequency of 2400Hz in
a fullwave "star" configuration, with only 13% ripple, no? The same holds
for early model Cybers (even before they were called "Cyber") which used a
different variety of logic.
Well, yes, of course. Which leads to the question why
DEC did not go
that route. I guess the KL10 power supply people were drunk (again).
11:51 p.m.
On Tue, Nov 25, 2014 at 7:49 PM, Jon Elson <elson at pico-systems.com> wrote:
At least, the KL10B power supply DID work reliably.
Our university didn't
care about the power waste, but obviously it was a big problem for
Compuserve.
The KL10 power supply could ride through at least two dropped AC line
cycles, thanks to the 3.9F capacitor box. The nominal DC voltage was
about 11.2V IIRC, and the regulators needed about 2V of headroom, so
the machine could operate until the capacitors sagged by about 4V. Of
course, the linear power supplies effectively became more efficient as
the capacitors sagged.
6:42 p.m.
On 11/25/2014 02:18 PM, Eric Smith wrote:
Well, the KL10 was not an early CPU design. There are ways
to make good switching
supplies, DEC should have done the engineering. I'm sure
even **I** could have built
a workable switching supply.
Jon
On Mon, Nov 24, 2014 at 8:46 PM, Jon Elson <elson
at pico-systems.com> wrote:
There may have been several versions. The KL10B in a
Decsystem 2020 we had had
one big regulator that was a ring of "christmas tree"
segments with a fan about 10"
in diameter. This was all 30 years ago, so my memory may
have faded just a
little, but I'm pretty sure that was how it was done. Quite
insane. DEC started
using switching regulators in all large DC supplies in the
late 60's, and if ever
there was a machine that cried out for a switching regulator
it sure was the
KL10! So, the decision to use a linear regulator with a
huge voltage drop
must have been some misguided belief that ECL was too noise
sensitive
for a switching regulator. I have built smaller systems
with ECL, and found
it to be quite noise-tolerant.
The KL10B had an immense 3-phase transformer,
star rectifier and capacitor
bank,
About 3.9F worth of capacitors, which was a heck of a lot back in the mid
1970s.
which produced about 12 V DC. This was fed to a
massive linear
regulator on a huge round heat sink.
Actually to 13 massive linear regulators on
multiple large heat sinks. Compuserve ran
a LOT of KL10B's, and designed
their own switching power supplies to save power and air conditioning costs. They
never got DEC to pick up on that, so had to retrofit all the machines as they came
in.
When the KL10 was designed, DEC was already using switching power
supplies in some machines (e.g., PDP-11/40, /45, /55, /70). However,
the load regulation, ripple, and noise specs weren't great, and ECL is
sensitive to the ripple and noise. By the time Compuserve designed
their replacement, switching power supply technology had improved
somewhat.
11:47 p.m.
On Tue, Nov 25, 2014 at 7:42 PM, Jon Elson <elson at pico-systems.com> wrote:
On 11/25/2014 02:18 PM, Eric Smith wrote:
A DECSYSTEM-2020 uses a KS10, which has no ECL, and uses a big
switching power supply made by third parties. The KL10B was used in
the DECsystem-1090, but not in any DECSYSTEM-20 models. The KL10BC
was used in the DECsystem-1090T, which was ran TOPS-20 but was not
marked as a DECSYSTEM-20. The other DECSYSTEM-20 models (2040, 2050,
2060, 2065) all use the KL10-C, KL10-E, or KL10-E/R processors.
Actually to 13 massive linear regulators on
multiple large heat sinks.
There may have been several versions. The KL10B in a
Decsystem 2020 we had had one big regulator that was a ring of
"christmas tree" segments with a fan
about 10" in diameter.
They wouldn't have used one big regulator because the remote sensing
wouldn't have been able to get a sufficiently uniform voltage on all
backplane segments, and that definitely *will* cause problems for ECL.
Also it has to be at least two regulators because the backplanes need
regulated -5.2V and -2.0V. And one big regulator for 315A of -5.2V
wouldn't have significantly less expensive then nine 35A regulators,
because it would have needed just as many pass transistors and just as
much heat sinking.
According to the maintenance docs, even the earliest production KL10s
used The H761 Regulator Assembly which had five heat sink
subassemblies for the pass transistors for nine -5.2V 35A regulators,
with room for a tenth, and four -2.0V 35A regulators. Each heat sink
assembly was a rectangular affair with a squarish profile with a
blower at one end, and is designed for pass transistors for up to four
regulators. HSA1 and HSA2 each have the pass transistors for two -2.0V
regulators, HA3 and HA4 for four -5.2V regulators each, and HSA5 for
two -5.2V regulators, one of which was not used in any normal KL10
configuration. All five HSAs and the control circuitry are attached
to a single rack mounting panel, which normally has a cover in place.
The HSA mounts are hinged for service access.
See for example assembly drawing E-UA-H761-0-0 for the complete
assembly, dated November 1974, and E-AD-7009404-0-0 and
E-AD-7009405-0-0 assembly drawings for the individual HSAs. These are
in the FMPS for the KL10A:
http://www.textfiles.com/bitsavers/pdf/dec/pdp10/KL10/MP-KL10-A1_KL10_vol1_…
I don't see a print set for the KL10B online, but I'm confident that
the H761 Regulator Assembly was the same.
26 Nov
26 Nov
10:35 a.m.
On 11/26/2014 01:47 AM, Eric Smith wrote:
On Tue, Nov 25, 2014 at 7:42 PM, Jon Elson <elson
at pico-systems.com> wrote:
Not true! The CPU was,
absolutely, a KL10B. It was in a
big orange cabinet that was
fairly similar in size and shape to a VAX 11/780. It had a
PDP 11/40 (I think) in the
next bay over as the I/O processor. I am not so clear about
the exact "DECSystem"
designation, but it VERY much was a DECSystem 20<something>.
During a major
upgrade, the FE had the print set out, plus all the boards
that were being
replaced with upgraded boards. I got a VERY good look at
the print set and the
boards. Very typical MECL 10K logic, a million terminating
and pull-down
resistors all over the place. I was most interested in the
clock alignment system.
They had zig-zag traces with a piece of wire-wrap wire that
were hand-soldered
to tap onto the zig-zag at the right point to set the clock
delay. The label on
the front of the cabinet said "DECSystem-20" without
specifically giving the
model number.
On 11/25/2014 02:18 PM, Eric Smith wrote:
A DECSYSTEM-2020 uses a KS10, which has no ECL, and uses a
big
switching power supply made by third parties. The KL10B was used in
the DECsystem-1090, but not in any DECSYSTEM-20 models. Actually to 13 massive linear regulators on
multiple large heat sinks.
There may have been several versions. The KL10B in a
Decsystem 2020 we had The KL10BC
was used in the DECsystem-1090T, which was ran TOPS-20 but was not
marked as a DECSYSTEM-20. The other DECSYSTEM-20 models (2040, 2050,
2060, 2065) all use the KL10-C, KL10-E, or KL10-E/R processors.
OK, the
thing was all on one huge fan, but there were dozens
of power transistors on
individual heat sink segments, all arranged in a circle
around the fan. So, yes,
there were several regulators, electrically, but the main
pass transistors were all
mounted in a single unit.
Yes, if you don't go the
Seymour Cray route and run EVERY DAMN SIGNAL differential
had one big regulator that was a ring of
"christmas tree" segments with a fan
about 10" in diameter.
They wouldn't have used one big regulator because
the remote sensing
wouldn't have been able to get a sufficiently uniform voltage on all
backplane segments, and that definitely *will* cause problems for ECL. from one board to the
next, then you do have to
be careful that the power supplies
are fairly well matched.
I don't see a print set for the KL10B online, but I'm confident that
the H761 Regulator Assembly was the same.
No, I think there was an "early" version and a "late"
version. The system was not
greatly different, but they reduced the number of separate
regulators and I think
cut one whole regulator board out of the system that way.
This late model might have
been the KL10-BC you mention, although I'm PRETTY sure the
print set did not carry
that ending C, at least on the front page. And, maybe the
system was a 2040.
This is all from almost 25 years ago, and I was not a user
on that machine, we took
over the machine room after the 20xx was moved to another
building.
Jon
12:28 p.m.
On Wed, Nov 26, 2014 at 11:35 AM, Jon Elson <elson at pico-systems.com> wrote:
Both the KL10-A (earliest version) and the KL10-E/R (lastest version)
used exactly the same H861 regulator assembly.
On 11/26/2014 01:47 AM, Eric Smith wrote:
As I said, it's not a 2020, and if it's any other model of DEC 20,
it's a KL10-C,
KL10-E, or LK10-ER.
You might be confusing the "Model B" designation (multiple section,
vs. "Model A" which is single section) with the KL10 suffix, but
they're not the same thing. A 2040 or 2050 can be either Model A or
model B, but are the KL10-C, KL10-E, or KL10-E/R hardware models.
The "Model A" means that the logic assembly inside the KL10 is a
KL10-PA, while "Model B" may be KL10-PV or KL10-PW:
Marketing software Full KL10 KL10 CPU
Designation "model" P/N logic assy
--------------------------- ------------ ------------ -------------
DECsystem-1080 Model A KL10-A KL10-PA
DECsystem-1090 Model A KL10-B KL10-PA
*or* Model B KL10-D KL10-PV
DECsystem-1090T Model A KL10-BC KL10-PA
DECsystem-1091 Model B KL10-E/R KL10-PV
DECsystem-1095 Model B KL10-E/R KL10-PW
DECSYSTEM-2040 Model A KL10-C KL10-PA
*or* Model B KL10-E KL10-PV
DECSYSTEM-2050 Model A KL10-C KL10-PA
*or* Model B KL10-E/R KL10-PV
DECSYSTEM-2060 Model B KL10-E/R KL10-PV
DECSYSTEM-2065 Model B KL10-E/R KL10-PW
The KL10-R was the FCC-compliant version of the KL10-E.
On Tue, Nov 25, 2014 at 7:42 PM, Jon Elson <elson at pico-systems.com> wrote:
Not true! The CPU was, absolutely, a KL10B. It was in a big orange cabinet
that was
fairly similar in size and shape to a VAX 11/780. It had a PDP 11/40 (I
think) in the
next bay over as the I/O processor. I am not so clear about the exact
"DECSystem"
designation, but it VERY much was a DECSystem 20<something>.
On 11/25/2014 02:18 PM, Eric Smith wrote:
A DECSYSTEM-2020 uses a KS10, which has no ECL, and uses a big
switching power supply made by third parties. The KL10B was used in
the DECsystem-1090, but not in any DECSYSTEM-20 models.
Actually to 13 massive linear regulators on multiple large heat sinks.
There may have been several versions. The KL10B in a Decsystem 2020 we
had OK, the thing was all on one huge fan, but there were
dozens of power
transistors on
individual heat sink segments, all arranged in a circle around the fan. So,
yes,
there were several regulators, electrically, but the main pass transistors
were all
mounted in a single unit.
Totally contrary to every KL10 I've ever seen, and all the published
maintenance documentation. There's an individual fan on each heat
sink, and they are arranged in a rectangular fashion. I really don't
believe that DEC built a special version just for you.
Yes, if you don't go the
Seymour Cray route and run EVERY DAMN SIGNAL differential from one board to
the
next, then you do have to be careful that the power supplies are fairly well
matched.
It's not a matter of timing, though that was a concern too. If they
used a single big regulator, the voltage to each part of the backplane
would be different, and ECL has very low noise margins relative to the
supply voltage, so it won't work reliably. They have separate
regulators each with independent remote sense, and special provision
for handling a failure of remote sensing to prevent the ECL from being
damaged.
I don't
see a print set for the KL10B online, but I'm confident that
the H761 Regulator Assembly was the same.
No, I think there was an
"early" version and a "late" version. The system was not greatly different, but they reduced the number
of separate regulators and I
think cut one whole regulator board out of the system that way.
They never eliminated any ECL regulator board. All KL10s have nine
5.2V regulators and four 2.0V regulators. The only thing eliminated
was the tenth 5.2V regulator, which was never used in any KL10 model.
I've owned a KL10-B, which had been upgraded to a KL10-D, and a
KL10-R. I'd take pictures of the regulator assemblies of both, but
I'm about 1500 miles away from them.
I also hung out with the field service guy for the Colorado School of
Mines KL10-A in my misspent youth.
6:05 p.m.
On 11/26/2014 02:28 PM, Eric Smith wrote:
Totally contrary to every KL10 I've ever seen, and
all the
published maintenance documentation. There's an individual
fan on each heat sink, and they are arranged in a
rectangular fashion. I really don't believe that DEC built
a special version just for you. Both the KL10-A (earliest
version) and the KL10-E/R (lastest version) used exactly
the same H861 regulator assembly.
Well, that's what 35 years will do to your memory! I guess
I'd better stick to
11/45, 11/780 and uVAX II, which I worked so much with that
I won't get much
wrong.
Jon
was not greatly different, but they reduced the
number of separate regulators and I
think cut one whole regulator board out of the system that way.
They never
eliminated any ECL regulator board. All KL10s have nine
5.2V regulators and four 2.0V regulators. The only thing eliminated
was the tenth 5.2V regulator, which was never used in any KL10 model.
24 Nov
24 Nov
1:40 p.m.
Jon Elson wrote:
On 11/23/2014 03:15 PM, Holm Tiffe wrote:
but sine you already have 240V outlets, it should
be
possible to change the distribution slowly to 3 phase
power.. it's a matter of time and the only needed thing
for compatibility are the transformers with modified
secondaries. I don't think that this would ever happen
since the US is the biggest US of the world and other
people are just dumb aliens, aren't they? :-) But with
that stone age power system you are stumbling over your
own feet all the time.. Regards, Holm
Well, we only have single phase 7200 V running down our
street. This 7200 V run goes a LONG way,
so an entire region that may be about a mile square is
running off a single phase HV line, that
branches over and over again into the neighborhood. Many of
these feeds that go back
into subdivisions are buried, and have pad-mount
transformers placed every few homes.
Our house has a pole-mount 50 KVA transformer that supplies
just our one house, although
that is kind of an accident of the layout. We are on the
corner lot, and otherwise probably
would have shared that transformer with a neighbor. Our LV
drop is buried. So, what I'm saying here is there is a lot of
high-cost
infrastructure that would have to be
ripped up (literally out of the ground) to go to 3 phase
into the homes. Not to mention
all the meters, service entry gear and breaker panels.
I understand that it will be very expensive to change such a "naturally
grown" infrastructure and this is that cause that I wrote that the US
should have changed this long before nowi, where it is really to late to do
that.
Here in germany 1 phase power lines simply don't exist. The entire
infrastructure is build with 3 phases and the phase balancing is made on
every distribution paneel in every house. This is why it isn't a big
problem to get a 3 phase outlet installed somewhere you need it.
Most cables are in the ground, but on the other end of my village here
(1km distance to the next city) there are some overhead lines with at least
two transformers on masts that distribute 3x400V to groups of houses.
I have a small machine shop in my basement, and some years
ago it seemed like 3-phase
would be real nice for that. Now that VFDs can run 3-phase
motors so nicely off single
phase power, it is no longer of much interest.
Vacuum Flourescence Displays? :-)
No, I know what you mean, and I have a unused small one (1500 Watts
I think) that accepts single Phase 230V and puts out 3phase.
I've put an FU (Frequenzumrichter, Frequency Inverter) on my old lathe from
tne beginig of the fifties, ABB 2,2KW.
BTW: Is it normal that american made asynchronous 3phase motors don't have
a "clamp board" like this:
http://www.elektrikforen.de/attachments/motoren-sch-tze-und-schaltungen/334…
..and use 6 flying wires and a bag full washers,screws and nuts
instead? My lathe has an US made Motor (..unusual voltages if I remember
correctly, but one circuit fits well, forgot if star or triangle)
Got this motor from a friend and saw the first time one without that clamp
board (clamp board may not be correct, in german thats called Klemmbrett).
Unless you desire to run a Cray 1 in your home (yeah, keep
dreaming) there really isn't
that much need for 3-phase power. Most machines that
"require" 3-phase can actually
be rewired internally to run off single-phase. One I can
think of that won't is the
KL-10B, which had a totally insane power system starting
with a 3-phase transformer
and rectifier. A mid-scale 370 like the 145 had a
motor-generator set, which could be
run off a large VFD. Or, replace the stupid MG and 415 Hz
power supplies with
off-the-shelf large power supplies running off single-phase
240 V.
Jon
Again, I can accept that you are able to solve problems resulting from that
single phase problem, but I know what would be the better way to do it.
Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
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49 comments
18 participants
participants (18)
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abuse＠cabal.org.uk -
ard＠p850ug1.demon.co.uk -
bqt＠update.uu.se -
cclist＠sydex.com -
charles＠uniwho.com -
cisin＠xenosoft.com -
dgriffi＠cs.csubak.edu -
elson＠pico-systems.com -
ggs＠shiresoft.com -
hilpert＠cs.ubc.ca -
holm＠freibergnet.de -
jim＠photojim.ca -
jnc＠mercury.lcs.mit.edu -
jws＠jwsss.com -
mhs.stein＠gmail.com -
pete＠dunnington.plus.com -
spacewar＠gmail.com -
wdonzelli＠gmail.com