15 Jun
2009
15 Jun
'09
10:48 p.m.
So in my hunt to find more information on switches I want to
clean/replace(that was mentioned in another thread), I took this Brian
Instruments Brikon 723 floppy drive analyzer apart.
I've taken my share of equipment apart, but I can't believe the size of
the components inside. Can someone help me make sense of this design?
I find no fewer than 4 HUGE transformers:
(2) Pacific 0288 DP100-16
(1) Pacific 0288 DP100-28
(1) Pacific 0388 DP30-36
There appear to be (7) terminals on each transformer. Maybe +,-,GND on
the primary AC side, and then (4) terminals on the secondary DC side?? I
guess all (4) terminals would be the same voltage?
I've emailed Pacific for the datasheets --- I doubt they are current
products.
Then, there are these huge capacitors, (8) Frako 3300uf ones.
There are about 20 leds and 20 switches on the front panel, which are
not easily accessible from the back side. The front panel has a half
dozen 7-segment LEDs.
One of the more prominent socketed chips is a Burr-Brown DAC80-CBI-V.
(http://www.datasheetcatalog.org/datasheet/BurrBrown/mXrvxzt.pdf)
There are a few daughter cards with a bunch of 74LS logic chips. There
are other ICs that I can't get to without going deeper into the teardown.
There's a decent size fan on the back of the unit for cooling.
I guess I'm at a loss for the transformers. Why 4? So that you have
separate stable sources of DC power so that the pull from one doesn't
affect the others? Can I replace the power circuits with something
smaller and newer?
The transformers and caps make up easily 1/2 the total size inside the
chassis and easily 75% of the weight.
Thanks
Keith
16 Jun
16 Jun
1:12 p.m.
Keith Monahan wrote:
So in my hunt to find more information on switches I want to
clean/replace(that was mentioned in another thread), I took this Brian
Instruments Brikon 723 floppy drive analyzer apart.
I've taken my share of equipment apart, but I can't believe the size of
the components inside. Can someone help me make sense of this design?
I find no fewer than 4 HUGE transformers:
(2) Pacific 0288 DP100-16
(1) Pacific 0288 DP100-28
(1) Pacific 0388 DP30-36
There appear to be (7) terminals on each transformer. Maybe +,-,GND on
the primary AC side, and then (4) terminals on the secondary DC side?? I
guess all (4) terminals would be the same voltage?
I've emailed Pacific for the datasheets --- I doubt they are current
products.
Then, there are these huge capacitors, (8) Frako 3300uf ones.
There are about 20 leds and 20 switches on the front panel, which are
not easily accessible from the back side. The front panel has a half
dozen 7-segment LEDs.
One of the more prominent socketed chips is a Burr-Brown DAC80-CBI-V.
(http://www.datasheetcatalog.org/datasheet/BurrBrown/mXrvxzt.pdf)
There are a few daughter cards with a bunch of 74LS logic chips. There
are other ICs that I can't get to without going deeper into the teardown.
There's a decent size fan on the back of the unit for cooling.
I guess I'm at a loss for the transformers. Why 4? So that you have
separate stable sources of DC power so that the pull from one doesn't
affect the others? Can I replace the power circuits with something
smaller and newer?
The transformers and caps make up easily 1/2 the total size inside the
chassis and easily 75% of the weight.
(Pictures are always nice for making such assessments. ("HUGE" may
be quite relative to one's experience.))
The number of transformers may have been simply a manufacturing economics
issue. A floppy drive analyser is going to be produced in relatively small
numbers, and they may have chosen to use 4 off-the-shelf types rather than
having one special transformer specced and manufactured. Maximum physical
dimensions might even have been an issue. If it's an early analyser
targetting 8-inch drives as well as 5-inch, one of the transformers is
probably to supply the 24V that some 8-inch drives required.
The -16, -28, -36 are probably the secondary voltages.
A guess might be: one -16 split-phase rectified for the 5VDC logic, one -16 for
12VDC to the floppies, the -28 for 24VDC to 8-inch floppies, the -36 is weird
but it could even be dual-half-wave rectified for +/-12VDC for the logic if
such is required internally.
8 3300uF caps doesn't sound excessive for several linear supplies, some of them
are probably parrelled.
Regarding the 7 terminals, one possibility is they have dual primaries for
120/240 VAC operation. That would eat up 4 terminals, leaving 3 for
center-tapped secondary or 2+earth(shield).
1:43 p.m.
On Tue, 2009-06-16 at 10:26 -0700, Brent Hilpert wrote:
Brent Hilpert wrote:
There were, there just weren't enough vowels and one of the consonants
was the wrong one.
Gordon
8 3300uF caps doesn't sound excessive for
several linear supplies, some of them
are probably parrelled.
^^^^^^^^^
paralleled
Somehow in the morning haze it looked like there were enough consonants in
there the first time.
1:56 p.m.
Gordon JC Pearce wrote:
On Tue, 2009-06-16 at 10:26 -0700, Brent Hilpert wrote:
.. the morning haze still hadn't cleared completely when I stated the correction.
Brent Hilpert wrote:
There were, there just weren't enough vowels and one of the consonants
was the wrong one. 8 3300uF caps doesn't sound excessive for
several linear supplies, some of them
are probably parrelled.
^^^^^^^^^
paralleled
Somehow in the morning haze it looked like there were enough consonants in
there the first time.
6:04 p.m.
Brent Hilpert wrote:
Gordon JC Pearce wrote:
My wonderful, patient wife is an English teacher, and an easy way to rev
her up is to remind her that English is a living language, subject to
constant change, and that the only language that has truly static
spelling is Latin! Remember - "I before E, unless after C (and then
only sometimes)"
On Tue, 2009-06-16 at 10:26 -0700, Brent Hilpert
wrote:
.. the morning haze still hadn't cleared completely when I stated the correction.
Brent Hilpert wrote:
There were, there just weren't enough vowels and one of the consonants
was the wrong one.
8 3300uF caps doesn't sound excessive for
several linear supplies, some of them
are probably parrelled.
^^^^^^^^^
paralleled
Somehow in the morning haze it looked like there were enough consonants in
there the first time.
11:09 p.m.
On Wed, 17 Jun 2009, Doug Jackson wrote:
There were, there just weren't enough vowels and one of the consonants
was the wrong one.
.. the morning haze still hadn't cleared completely when I stated the correction.
My wonderful, patient wife is an English teacher, and an easy way to rev
her up is to remind her that English is a living language, subject to
constant change, and that the only language that has truly static
spelling is Latin! Remember - "I before E, unless after C (and then
only sometimes)"
--
Fred Cisin cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
5:36 p.m.
New subject: [OT] English spelling [was RE: Taking apart a Brikon 723 floppy drive analyzer]
From: Doug Jackson
Sent: Tuesday, June 16, 2009 3:05 PM
My wonderful, patient wife is an English teacher, and
an easy way to
rev her up is to remind her that English is a living language, subject
to constant change, and that the only language that has truly static
spelling is Latin! Remember - "I before E, unless after C (and then
only sometimes)"
Not even Latin spelling is entirely static--ecclesiastical Latin
spellings often differ from the classical language.
And it's
i before e except after c,
if the sound of the word is 'long e'
which, as someone with multiple degrees in linguistics, irritates me a
bit (there being no such thing as "long" vowels in modern English--it's
a holdover from Graeco-Latin grammars).
Rich Alderson
Vintage Computing Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
(206) 342-2239
(206) 465-2916 cell
http://www.pdpplanet.org/
6:28 p.m.
New subject: [OT] English spelling [was RE: Taking apart a Brikon 723 floppy drive analyzer]
On Wed, Jun 17, 2009 at 2:36 PM, Rich Alderson <RichA at vulcan.com> wrote:
I'm not sure about you, but for me the "long" qualifier was taught
as
denoting vowels that 'sound like their names', i.e. the A in 'plate' as
opposed to the A in 'flat'.
Now, being in the process of trying to teach myself Latin, I understand what
you're saying, but I guess you must decide if you want to accept modern
usage as the new "correct" use or not.
Also, we learned it as:
i before e except after c,
or when sounded as 'a'
like in neighbor and weigh.
John
--
"I've tried programming Ruby on Rails, following TechCrunch in my RSS
reader, and drinking absinthe. It doesn't work. I'm going back to C, Hunter
S. Thompson, and cheap whiskey." -- Ted Dziuba
From: Doug
Jackson
Sent: Tuesday, June 16, 2009 3:05 PM
My wonderful, patient wife is an English teacher,
and an easy way to
rev her up is to remind her that English is a living language, subject
to constant change, and that the only language that has truly static
spelling is Latin! Remember - "I before E, unless after C (and then
only sometimes)"
Not even Latin spelling is entirely static--ecclesiastical Latin
spellings often differ from the classical language.
And it's
i before e except after c,
if the sound of the word is 'long e'
which, as someone with multiple degrees in linguistics, irritates me a
bit (there being no such thing as "long" vowels in modern English--it's
a holdover from Graeco-Latin grammars).
10:19 p.m.
New subject: [OT] English spelling [was RE: Taking apart a Brikon 723 floppy drive analyzer]
Rich Alderson wrote:
Not even Latin spelling is entirely
static--ecclesiastical Latin
spellings often differ from the classical language.
And it's
i before e except after c,
if the sound of the word is 'long e'
I always learned it as:
I before E except after C
Except when sounding like A
As in "neighbor" and "weigh"
Peace... Sridhar
16 Jun
16 Jun
3:06 p.m.
There appear to be (7) terminals on each transformer.
Maybe +,-,GND on
the primary AC side, and then (4) terminals on the secondary DC side?? I
guess all (4) terminals would be the same voltage?
It would be more common to have 4 primary (mains) side terminals and 3
secondary terminals. There would be 2 115V primary windings which can be
connected in parallel for 115V mains or series for 230V mains and a
centre-tapped secondary that can be used witha couple of diodes as a
full-wave rectifier.
If there are 3 terminals on the mains side, it's possible one is an
inter-winding screen (sheild) and is connected to ground. 4 secondary
terminals would suggest 2 separate windings (which may or may not be the
same voltage).
-tony
5508
days inactive
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12 comments
9 participants
participants (9)
-
ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
doug＠stillhq.com -
gordonjcp＠gjcp.net -
hilpert＠cs.ubc.ca -
keithvz＠verizon.net -
ploopster＠gmail.com -
RichA＠vulcan.com -
slawmaster＠gmail.com