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I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
All you need are the two 30V windings and the 90V winding; the restI think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
On 2019/09/11 8:23 p.m., jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Any particular reason you want the four windings in parallel for the 30
volt output? Otherwise it can be easily done with two relays.
Seems to me you would be trusting the transformer consistency a bit too
much have four winding in parallel in your solution, won't it get a bit
warm if there is any buck/boost from having the windings in parallel?
John :-#)#
On 2019/09/11 8:23 p.m., jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Any particular reason you want the four windings in parallel for the 30
volt output? Otherwise it can be easily done with two relays.
Seems to me you would be trusting the transformer consistency a bit too
much have four winding in parallel in your solution, won't it get a bit
warm if there is any buck/boost from having the windings in parallel?
John :-#)#
jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
All you need are the two 30V windings and the 90V winding; the rest
is fluff.
Take a look at http://cq.cx/ladder.pl
On Thu, 12 Sep 2019 00:32:00 -0700, John Robertson <spam@flippers.com
wrote:
On 2019/09/11 8:23 p.m., jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Any particular reason you want the four windings in parallel for the 30
volt output? Otherwise it can be easily done with two relays.
Seems to me you would be trusting the transformer consistency a bit too
much have four winding in parallel in your solution, won't it get a bit
warm if there is any buck/boost from having the windings in parallel?
John :-#)#
To use all the copper all the time, which keeps the output impedance
down and gives max VA on all settings. The 600 watt class-D amp chip
is $6, but the huge 120 VA transformer costs $65.
Transformers are wound with exactly the number of designed turns.
Windings in parallel are OK.
I also want a "fault" state, namely open circuit. I can drive three
relay coils independently, which is 8 states. Maybe I can find or make
an "open" state, still with three DPDT relays.
I don't have any systematic way to do relay logic. The only formal
structure that I know of is the tree that makes a 1:2^N mux;
everything else is just fiddling. Hurts my head.
On 2019/09/12 7:27 a.m., jlarkin@highlandsniptechnology.com wrote:
On Thu, 12 Sep 2019 00:32:00 -0700, John Robertson <spam@flippers.com
wrote:
On 2019/09/11 8:23 p.m., jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Any particular reason you want the four windings in parallel for the 30
volt output? Otherwise it can be easily done with two relays.
Seems to me you would be trusting the transformer consistency a bit too
much have four winding in parallel in your solution, won't it get a bit
warm if there is any buck/boost from having the windings in parallel?
John :-#)#
To use all the copper all the time, which keeps the output impedance
down and gives max VA on all settings. The 600 watt class-D amp chip
is $6, but the huge 120 VA transformer costs $65.
Transformers are wound with exactly the number of designed turns.
Windings in parallel are OK.
I also want a "fault" state, namely open circuit. I can drive three
relay coils independently, which is 8 states. Maybe I can find or make
an "open" state, still with three DPDT relays.
I don't have any systematic way to do relay logic. The only formal
structure that I know of is the tree that makes a 1:2^N mux;
everything else is just fiddling. Hurts my head.
Your schematic sketch is slightly off then, relay K2's second contact
layout is reversed - the drawing shows one SPDT switch going clockwise
and the 2nd SPDP has to mentally go counterclockwise for it to work
correctly. You need to redraw the second half of K2 so it looks like the
2nd half of K3. Electrically the same, schematically then correct.
I still work on EM stuff all the time... I had ignored the Class D note,
didn't think it was important, my mistake!
On 2019-09-12 05:23, jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Hi, here is a slightly different take on that one.
Schematic: https://img.wenhairu.com/image/87tbN
Again, the circuit uses 3 relays, but K1 and K2 can be paralleled, or if
a relay with 4 changeover contact pairs ("4-pole 2-throw") is available
then K1 and K2 can be combined into that one relay.
The basic principle is that windings form virtual pairs and each pair is
controlled by one relay to be either in series or in parallel. A final
relay controls the "pair of pairs" in the same way.
It is possible to use independent K1 and K2 too, this allows an extra
output selection of 90V in addition to 30V, 60V and 120V. The 90V option
has a somewhat reduced current capability, its configuration is that one
pair of windings is in parallel and all the others are in series.
However when K1 and K2 are used independently, an invalid state must be
avoided: When K1 and K2 have unequal states (one is on, the other is
off, no matter in which order) then K3 must never be on at the same
time. That would result in a transformer overload (paralleling of
unequal windings is like a short circuit), however this is avoidable by
disabling K3 through an override whenever "K1 xor K2" is true.
Regards, Dimitrij
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
On Thu, 12 Sep 2019 20:48:44 +0200, Dimitrij Klingbeil
nospam@no-address.com> wrote:
On 2019-09-12 05:23, jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Hi, here is a slightly different take on that one.
Schematic: https://img.wenhairu.com/image/87tbN
Again, the circuit uses 3 relays, but K1 and K2 can be paralleled, or if
a relay with 4 changeover contact pairs ("4-pole 2-throw") is available
then K1 and K2 can be combined into that one relay.
The basic principle is that windings form virtual pairs and each pair is
controlled by one relay to be either in series or in parallel. A final
relay controls the "pair of pairs" in the same way.
It is possible to use independent K1 and K2 too, this allows an extra
output selection of 90V in addition to 30V, 60V and 120V. The 90V option
has a somewhat reduced current capability, its configuration is that one
pair of windings is in parallel and all the others are in series.
However when K1 and K2 are used independently, an invalid state must be
avoided: When K1 and K2 have unequal states (one is on, the other is
off, no matter in which order) then K3 must never be on at the same
time. That would result in a transformer overload (paralleling of
unequal windings is like a short circuit), however this is avoidable by
disabling K3 through an override whenever "K1 xor K2" is true.
Regards, Dimitrij
That's nice, more orderly than mine. Relay drivers are cheap (we use
TPIC6595) so I may as well control the three relays independently and
offer 90 volts as a feature. Thanks.
These are nice looking DPDT relays
https://www.digikey.com/product-detail/en/te-connectivity-potter-brumfield-relays/RT424024/PB969-ND/1095293
with several sources.
On Thu, 12 Sep 2019 20:48:44 +0200, Dimitrij Klingbeil
nospam@no-address.com> wrote:
On 2019-09-12 05:23, jlarkin@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
Hi, here is a slightly different take on that one.
Schematic: https://img.wenhairu.com/image/87tbN
Again, the circuit uses 3 relays, but K1 and K2 can be paralleled, or if
a relay with 4 changeover contact pairs ("4-pole 2-throw") is available
then K1 and K2 can be combined into that one relay.
The basic principle is that windings form virtual pairs and each pair is
controlled by one relay to be either in series or in parallel. A final
relay controls the "pair of pairs" in the same way.
It is possible to use independent K1 and K2 too, this allows an extra
output selection of 90V in addition to 30V, 60V and 120V. The 90V option
has a somewhat reduced current capability, its configuration is that one
pair of windings is in parallel and all the others are in series.
However when K1 and K2 are used independently, an invalid state must be
avoided: When K1 and K2 have unequal states (one is on, the other is
off, no matter in which order) then K3 must never be on at the same
time. That would result in a transformer overload (paralleling of
unequal windings is like a short circuit), however this is avoidable by
disabling K3 through an override whenever "K1 xor K2" is true.
Regards, Dimitrij
That's nice, more orderly than mine. Relay drivers are cheap (we use
TPIC6595) so I may as well control the three relays independently and
offer 90 volts as a feature. Thanks.
These are nice looking DPDT relays
https://www.digikey.com/product-detail/en/te-connectivity-potter-brumfield-relays/RT424024/PB969-ND/1095293
with several sources.
I can kill the class-D amp input when we switch the relays, to avoid
transient faults.
Anyone remember that guy who used to post on one of the sci.electronics
groups several years ago who seemed like he was trying to control a
whole house and barn electrical system with relay logic?
bitrex wrote:
Anyone remember that guy who used to post on one of the sci.electronics
groups several years ago who seemed like he was trying to control a
whole house and barn electrical system with relay logic?
What would it be a silly idea? You don't need high speed there and
relays are insanely immune to surges, especially when they are in a
stable state during the surge.
Best regards, Piotr
bitrex wrote:
Anyone remember that guy who used to post on one of the
sci.electronics groups several years ago who seemed like he was trying
to control a whole house and barn electrical system with relay logic?
What would it be a silly idea? You don't need high speed there and
relays are insanely immune to surges, especially when they are in a
stable state during the surge.
    Best regards, Piotr
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
On Wednesday, September 18, 2019 at 3:08:11 AM UTC-4, Piotr Wyderski wrote:
bitrex wrote:
Anyone remember that guy who used to post on one of the sci.electronics
groups several years ago who seemed like he was trying to control a
whole house and barn electrical system with relay logic?
What would it be a silly idea? You don't need high speed there and
relays are insanely immune to surges, especially when they are in a
stable state during the surge.
Best regards, Piotr
Relay control of lights and outlets in high end homes was common in the '60s and '70s. A load could have a local switch, be remote controlled or from a timer and all with low current 24VAC wiring. A single switch could turn on every light on the property, if needed. That could be connected to the dry output of an alarm panel for security. I knew one electrical contractor who installed and maintained them, when I was teaching people to install alarm wiring.
On Wednesday, September 11, 2019 at 11:24:08 PM UTC-4, jla...@highlandsniptechnology.com wrote:
I think this is right. It was a minor brain sprain, after the banana
bread and rum.
https://www.dropbox.com/s/r6vg4fmnnwgk96y/30_60_120_3relays.JPG?raw=1
Imagine designing an entire dial telephone system with relays.
What's wrong with just stacking all the secondaries in series and then picking off the selected voltage at the appropriate tap? Isn't that just two relays?
And 30-60-120 is a weird progression.
On Wednesday, 18 September 2019 18:31:28 UTC+1, bitrex wrote:
On 9/18/19 6:45 AM, Michael Terrell wrote:
On Wednesday, September 18, 2019 at 3:08:11 AM UTC-4, Piotr Wyderski wrote:
bitrex wrote:
Anyone remember that guy who used to post on one of the sci.electronics
groups several years ago who seemed like he was trying to control a
whole house and barn electrical system with relay logic?
What would it be a silly idea? You don't need high speed there and
relays are insanely immune to surges, especially when they are in a
stable state during the surge.
Best regards, Piotr
Relay control of lights and outlets in high end homes was common in the '60s and '70s. A load could have a local switch, be remote controlled or from a timer and all with low current 24VAC wiring. A single switch could turn on every light on the property, if needed. That could be connected to the dry output of an alarm panel for security. I knew one electrical contractor who installed and maintained them, when I was teaching people to install alarm wiring.
as I recall the system this guy was working on was more like a relay
computer, switching 120V loads, and the relays themselves were 120V coil
types inside of feedback-loops driven off the loads themselves.
Like hairball-logic built with line voltages
Reminds me of a 1970s commercial scale misting unit, all relay logic run at 240v. Yes, in a soaking wet zone. No inbuilt checks, redundancy, fuses, RCD, anything. And made of asbestos.
NT