28 Nov
2014
28 Nov
'14
2:09 p.m.
On 28/11/2014 at 02:23, Jim Brain wrote:
I know this is not an electrical forum, but I thought
perhaps someone
has seen what I am looking for.
For an application, I am looking for a relay that is connected to 12V
through a switch, with the switch voltage also going to the middle of
a SPDT relay contacts.
* If I energize the latch once, for the time the button in pressed,
the relay flips "on" and the middle relay contact sends power to the
NO contact
* If the energize the latch a second time, for the time the button is
pressed, the relay flips "off" and the middle relay contact sends
power to the NC contact.
The circuit works with an open relay of the kind they used to use in
garage doors (push button once, and door goes up, second press makes
it go down...) But, we need a sealed relay to beat the weather (it's
for a lineman's bucket truck we own).
Simulating this with some electronics and two relays won't work (well,
it would work, but it's for my father, and he really wants a
electrical/mechanical relay solution, like he has, but weathertight).
I thought for sure there was such a thing as a D-type FF in relay
format, but all of the magnetic and mechanical latching relays I see
online use two separate coils to operate, which means two switches,
and that won't work (no more signal paths available in this application).
I must not know what to call what I am looking for, and was hoping
someone had a better name for this type of thing or a suggestion of
where to look...
Jim
I have come across a relay like this controlling the door of a bus. One push
to make switch, push once to open, push once to close. The bus schematics
called it an "impulse relay". This is East of the Atlantic - who knows if they
they call it the same thing where you are. The one I came across was 24V
rather that 12V too.
(There were no classic computer systems on the bus, unless you count the
radio system which allegedly tracked the bus location and radioed it back
to the controller. It counted pulses from the speedometer/odometer
tachogenerator and did 4 bit BCD arithmatic on them using 4000 series CMOS.)
Regards,
Peter Coghlan.
28 Nov
28 Nov
2:49 p.m.
On 11/28/2014 4:09 PM, Peter Coghlan wrote:
I have come across a relay like this controlling the
door of a bus.
One push to make switch, push once to open, push once to close. The
bus schematics called it an "impulse relay". This is East of the
Atlantic - who knows if they they call it the same thing where you
are. The one I came across was 24V rather that 12V too. (There were no
classic computer systems on the bus, unless you count the radio system
which allegedly tracked the bus location and radioed it back to the
controller. It counted pulses from the speedometer/odometer
tachogenerator and did 4 bit BCD arithmatic on them using 4000 series
CMOS.) Regards, Peter Coghlan.
I'll see if that set of words helps me. Google
was not all that useful
last night.
I'd like to find something and get it here within the week, as they are
coming back, and I'm hoping to test it out before I give it to him to
install in the unit.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
6:41 p.m.
On 2014-Nov-28, at 2:49 PM, Jim Brain wrote:
On 11/28/2014 4:09 PM, Peter Coghlan wrote:
I do have a design that sounds like what you want using 3 standard relays: one D/3PDT
& two 4PDT (or, one D/3PDT, one 3PDT, one 4PDT), or probably best to just call it
three 4PDT relays.
A single NO pushbutton would control the relays, wired to produce a net divide-by-2
effect.
Contacts on one of the relays would be used for the ON/OFF, in series with DT contacts on
one of the others to direct the UP/DOWN.
It's actually on-topic, as it's from a design exercise I did for the Simon relay
computer.
The (whole) schematic is linked on this page:
http://www.cs.ubc.ca/~hilpert/e/simon/imp.html
See the top-left corner of page 2 of the schematic, the ?, ?a & ?b relays.
There's a timing diagram in the timing section on the web page, the ? signal would
correspond to the button pushes.
It might be possible to reduce the number of contacts if one stared at the circuit long
enough.
It's been a few years since I worked on it, but I did prototype/test that part of the
circuit and had it clocking around 18Hz.
Relay logic is fun.
Perhaps it's more complex than what you'd like to implement, but if it's of
interest, or it's not clear, I could put together a more suitable diagram.
Perhaps the solenoid-triggerred 'mechanical flip-flop' relay Brian pointed to is
closer to what you want. One thing to note about that type is when the system is turned
off it can be left in - and hence will power-up in - either of the two states, you
wouldn't know initially whether it was going to go up or down, unless you knew from
the last time it was operated.
I have come across a relay like this controlling
the door of a bus. One push to make switch, push once to open, push once to close. The bus
schematics called it an "impulse relay". This is East of the Atlantic - who
knows if they they call it the same thing where you are. The one I came across was 24V
rather that 12V too. (There were no classic computer systems on the bus, unless you count
the radio system which allegedly tracked the bus location and radioed it back to the
controller. It counted pulses from the speedometer/odometer tachogenerator and did 4 bit
BCD arithmatic on them using 4000 series CMOS.) Regards, Peter Coghlan.
I'll
see if that set of words helps me. Google was not all that useful last night.
I'd like to find something and get it here within the week, as they are coming back,
and I'm hoping to test it out before I give it to him to install in the unit.
9:13 p.m.
On 11/28/2014 8:41 PM, Brent Hilpert wrote:
I do have a design that sounds like what you want
using 3 standard relays: one D/3PDT & two 4PDT (or, one D/3PDT, one 3PDT, one 4PDT),
or probably best to just call it three 4PDT relays.
A single NO pushbutton would control the relays, wired to produce a net divide-by-2
effect.
Contacts on one of the relays would be used for the ON/OFF, in series with DT contacts on
one of the others to direct the UP/DOWN.
It's actually on-topic, as it's from a design exercise I did for the Simon relay
computer.
The (whole) schematic is linked on this page:
http://www.cs.ubc.ca/~hilpert/e/simon/imp.html
See the top-left corner of page 2 of the schematic, the ?, ?a & ?b relays.
There's a timing diagram in the timing section on the web page, the ? signal would
correspond to the button pushes.
It might be possible to reduce the number of contacts if one stared at the circuit long
enough.
I looked at it for a while, and laid it out in Eagle, and I see what is
going on. Thanks for the idea.
I tried to simplify, but aside from using a few diodes to reduce the
number of poles in the Phi relay, I see no way to get around needing 1
4PDT (Relay A) and 1 3PDT (Relay B). Still, it's a plan.
Perhaps the solenoid-triggerred 'mechanical
flip-flop' relay Brian pointed to is closer to what you want. One thing to note about
that type is when the system is turned off it can be left in - and hence will power-up in
- either of the two states, you wouldn't know initially whether it was going to go up
or down, unless you knew from the last time it was operated.
Yes, I like your idea, because it always starts from a known state. But,
at least I have two options. I'll buy some 12VDC relays this week to
wire it up.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
9:17 p.m.
On 11/28/2014 06:41 PM, Brent Hilpert wrote:
...
So, this can be the basis:
https://www.circuitlab.com/circuit/4ndbv7/toggle-relay-flip-flop/
Add a 3rd DPDT relay with the coil connected to the Q output as a
reversing switch. The pushbutton (DPST) should have a second set of
contacts to control main power to the motor.
--Chuck
10:07 p.m.
On 11/28/2014 11:17 PM, Chuck Guzis wrote:
On 11/28/2014 06:41 PM, Brent Hilpert wrote:
...
So, this can be the basis:
https://www.circuitlab.com/circuit/4ndbv7/toggle-relay-flip-flop/
Add a 3rd DPDT relay with the coil connected to the Q output as a
reversing switch. The pushbutton (DPST) should have a second set of
contacts to control main power to the motor.
--Chuck
True, good catch. And, it looks like this could also be used to
simplify the SIMON design, if desired. It'd still take 3 relays, but
only 1 triple pole one
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
10:14 p.m.
On 11/28/2014 11:17 PM, Chuck Guzis wrote:
On 11/28/2014 06:41 PM, Brent Hilpert wrote:
...
So, this can be the basis:
https://www.circuitlab.com/circuit/4ndbv7/toggle-relay-flip-flop/
Add a 3rd DPDT relay with the coil connected to the Q output as a
reversing switch. The pushbutton (DPST) should have a second set of
contacts to control main power to the motor.
--Chuck
Actually, now that I look at this, I think it will only work with
momentary pushbutton presses, as the relay windows have to be half the
voltage used, as the voltage has to be high enough to energize both
relays in series.
I saw this design on another site, and the caveat was listed there, so I
think it applies here.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
11:26 p.m.
On 11/28/2014 10:14 PM, Jim Brain wrote:
Actually, now that I look at this, I think it will
only work with
momentary pushbutton presses, as the relay windows have to be half the
voltage used, as the voltage has to be high enough to energize both
relays in series.
So, put a capacitor with a bleeder in series with the pushbutton.
Shouldn't that work?
--Chuck
10:35 p.m.
Well, gee, if you're going to use a DPST pushbutton anyway, then all you
need is a single impulse relay like the original suggestion.
m
----- Original Message -----
From: "Chuck Guzis" <cclist at sydex.com>
To: <General at classiccmp.org>; "Discussion at classiccmp.org:On-Topic and
Off-Topic Posts" <cctalk at classiccmp.org>
Sent: Saturday, November 29, 2014 12:17 AM
Subject: Re: Relay question
On 11/28/2014 06:41 PM, Brent Hilpert wrote:
...
So, this can be the basis:
https://www.circuitlab.com/circuit/4ndbv7/toggle-relay-flip-flop/
Add a 3rd DPDT relay with the coil connected to the Q output as a
reversing switch. The pushbutton (DPST) should have a second set of
contacts to control main power to the motor.
--Chuck
10:58 p.m.
On 11/28/2014 10:35 PM, Mike Stein wrote:
Well, gee, if you're going to use a DPST
pushbutton anyway, then all you
need is a single impulse relay like the original suggestion.
Anyone remember Lionel trains? The power packs were AC (not DC as in
HO) and there was an impulse relay for reversing called an "E-Unit":
https://www.youtube.com/watch?v=C3cHF_a6CNM
--Chuck
29 Nov
29 Nov
9:17 a.m.
Anyone remember Lionel trains? The power packs were AC (not DC as in
HO) and there was an impulse relay for reversing called an "E-Unit":
The old O gauge Hornby trains (old meaning 1930s) were also AC. The motors
were series wound, a single field coil on a pole piece assembly that fitted round
a 3 pole armature. The pole piece was in 2 parts, spring loaded to open. When
the motor was running the magnetic field kept it all together, but with no supply
voltage it would open up. There was a pawl mechanism operated by the moving
part of the pole piece which swapped the connections to the brushes, so reversing
the motor. So every start was in the opposite direction.
Do Marklin still make AC HO gauge locomotives? IIRC they used an overvoltage to
toggle the reversing relay.
-tony
9:33 a.m.
I had a 3-Rail Hornby "O" gauge that used a toggle relay to reverse. I think
rather than over voltage it was set up so the relay had a very low "hold-in
voltage". It had a pawl that drove a commutator shaft that generated the
reversing. I think it was 24volt but might have been higher....
Dave
G4UGM
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
duell
Sent: 29 November 2014 17:17
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Relay question
fitted
Anyone remember Lionel trains? The power packs were AC (not DC as in
HO) and there was an impulse relay for reversing called an "E-Unit":
The old O gauge Hornby trains (old meaning 1930s) were also AC. The motors
were series wound, a single field coil on a pole piece assembly that round a 3 pole armature. The pole piece was in 2
parts, spring loaded to
open. When the motor was running the magnetic field kept it all together,
but with no supply voltage it would open up. There was a pawl mechanism
operated by the moving part of the pole piece which swapped the
connections to the brushes, so reversing the motor. So every start was in
the
opposite direction.
Do Marklin still make AC HO gauge locomotives? IIRC they used an
overvoltage to toggle the reversing relay.
-tony
11:46 a.m.
I had a 3-Rail Hornby "O" gauge that used a
toggle relay to reverse. I think
rather than over voltage it was set up so the relay had a very low "hold-in
voltage". It had a pawl that drove a commutator shaft that generated the
reversing. I think it was 24volt but might have been higher....
Sounds like the one I was describing, except that the relay coil was
the motor field winding with the moving pole piece acting as the
relay armature. The switch was a fibreboard disk with brass contact
plates on it and 3 spring contacts pressing on it. The fourth connection
was made via the pivot screw to the chassis, then to the wheels and back
to the track. I still have the motor unit somewhere, it'll turn up in the next
year or so as I unpack everything..
IIRC it was 20V AC
-tony
11:48 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
duell
Sent: 29 November 2014 19:46
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Relay question
motor
I had a 3-Rail Hornby "O" gauge that
used a toggle relay to reverse. I
think rather than over voltage it was set up so the relay had a very
low "hold-in voltage". It had a pawl that drove a commutator shaft
that generated the reversing. I think it was 24volt but might have been
higher....
Sounds like the one I was describing, except that the relay coil was the field winding with the moving pole piece acting as the
relay armature. The
switch was a fibreboard disk with brass contact plates on it and 3 spring
contacts pressing on it. The fourth connection was made via the pivot
screw
to the chassis, then to the wheels and back to the
track. I still have the
motor
unit somewhere, it'll turn up in the next year or
so as I unpack
everything..
IIRC it was 20V AC
-tony
I wosh I still had any of mine, it was FUN!
11:52 a.m.
I wosh I still had any of mine, it was FUN!
I think the motor I have came out of a 4-4-2 steam loco model. I may still have
bits of the body, the bogies are long gone, and I never had any of the track.
I gave away my OO gauge stuff (more recent, 2 rail, 12V DC) just before the
move. It went to a friend, officially for his son when he gets a bit older. But I
think we all know what that really means :-)
-tony
12:52 p.m.
Anyone remember Lionel trains?
Still around! Now, in addition to their usual offerings, they have very
expensive "collectible" higher detail models.
Neil Young bought a big hunk of the company, and also created "Lion-Tech"
which is involved with fancier control systems, realistic sound effects,
etc. (they used to (15 years ago) sublet a chunk of my office space for
their testing layout!)
The power packs were AC (not DC as in HO) and there
was an impulse relay
for reversing called an "E-Unit":
On Sat, 29 Nov 2014, tony duell wrote:
The old O gauge Hornby trains (old meaning 1930s) were
also AC.
Lionel WAS O gauge.
--
Grumpy Ol' Fred cisin at xenosoft.com
3444
days inactive
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15 comments
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ard＠p850ug1.demon.co.uk -
brain＠jbrain.com -
cclist＠sydex.com -
cctech＠beyondthepale.ie -
cisin＠xenosoft.com -
dave.g4ugm＠gmail.com -
hilpert＠cs.ubc.ca -
mhs.stein＠gmail.com