6 Dec
2022
6 Dec
'22
9:35 p.m.
This might be a bit off topic, so forgive me if so.
The issue is a 24VAC motor with one connection to 24VAC and the other
gated via two switches. The first switch is a momentary one and the
second is in parallel and connected to the motor. A long enough
momentary depression on the first switch actuates the electric motor
enough to close the second switch, which then stays closed for 1 revolution.
The problem is that a quick enough press and release of the first switch
does not allow the motor to move far enough to close the second switch.
Given the configuration, my general plan was a small one shot timer
circuit that energized when the switch was initially depressed and then
closed a relay in parallel with the first 2 switches, with a time period
that was 1/10 to 1/2 the time of the motor revolution. a quick close and
release of the first switch would start the timer, which would then
close the parallel switch and then open it a short time later, and then
the motor switch, which would still be closed, could signal the end of
the cycle.
But, I thought I'd ask around and see if a simpler option was available.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
7 Dec
7 Dec
6:43 a.m.
On Wed, Dec 7, 2022 at 12:40 AM Jim Brain via cctalk <cctalk(a)classiccmp.org>
wrote:
This might be a bit off topic, so forgive me if so.
The issue is a 24VAC motor with one connection to 24VAC and the other
gated via two switches. The first switch is a momentary one and the
second is in parallel and connected to the motor. A long enough
momentary depression on the first switch actuates the electric motor
enough to close the second switch, which then stays closed for 1
revolution.
The problem is that a quick enough press and release of the first switch
does not allow the motor to move far enough to close the second switch.
Given the configuration, my general plan was a small one shot timer
circuit that energized when the switch was initially depressed and then
closed a relay in parallel with the first 2 switches, with a time period
that was 1/10 to 1/2 the time of the motor revolution. a quick close and
release of the first switch would start the timer, which would then
close the parallel switch and then open it a short time later, and then
the motor switch, which would still be closed, could signal the end of
the cycle.
My two thoughts would be:
1) A 555-timer in one-shot mode
2) An S-R latch at is set by the push button, and cleared by 2nd switch
Pat
7:07 a.m.
That latch idea is neat! Both should work a treat.
Anders
On Wed, Dec 7, 2022, 9:44 AM Patrick Finnegan via cctalk <
cctalk(a)classiccmp.org> wrote:
On Wed, Dec 7, 2022 at 12:40 AM Jim Brain via cctalk
<
cctalk(a)classiccmp.org>
wrote:
This might be a bit off topic, so forgive me if
so.
The issue is a 24VAC motor with one connection to 24VAC and the other
gated via two switches. The first switch is a momentary one and the
second is in parallel and connected to the motor. A long enough
momentary depression on the first switch actuates the electric motor
enough to close the second switch, which then stays closed for 1
revolution.
The problem is that a quick enough press and release of the first switch
does not allow the motor to move far enough to close the second switch.
Given the configuration, my general plan was a small one shot timer
circuit that energized when the switch was initially depressed and then
closed a relay in parallel with the first 2 switches, with a time period
that was 1/10 to 1/2 the time of the motor revolution. a quick close and
release of the first switch would start the timer, which would then
close the parallel switch and then open it a short time later, and then
the motor switch, which would still be closed, could signal the end of
the cycle.
My two thoughts would be:
1) A 555-timer in one-shot mode
2) An S-R latch at is set by the push button, and cleared by 2nd switch
Pat
9:25 a.m.
On 12/7/2022 8:43 AM, Patrick Finnegan wrote:
My two thoughts would be:
1) A 555-timer in one-shot mode
That was my thought as well.
2) An S-R latch at is set by the push button, and
cleared by 2nd switch
Due to the vintage nature of the device, separating the
switches and
wiring them this way would require doing some invasive modification of
the unit, and it's not mine to modify. Though, I agree with other
comments, this S-R latch idea is a cool one.
Pat
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
9:28 a.m.
I don't suppose there's an extra NC contact on the motor switch/relay? If
so, a relay would do, otherwise two relays.
m
On Wed, Dec 7, 2022 at 12:40 AM Jim Brain via cctalk <cctalk(a)classiccmp.org>
wrote:
This might be a bit off topic, so forgive me if so.
The issue is a 24VAC motor with one connection to 24VAC and the other
gated via two switches. The first switch is a momentary one and the
second is in parallel and connected to the motor. A long enough
momentary depression on the first switch actuates the electric motor
enough to close the second switch, which then stays closed for 1
revolution.
The problem is that a quick enough press and release of the first switch
does not allow the motor to move far enough to close the second switch.
Given the configuration, my general plan was a small one shot timer
circuit that energized when the switch was initially depressed and then
closed a relay in parallel with the first 2 switches, with a time period
that was 1/10 to 1/2 the time of the motor revolution. a quick close and
release of the first switch would start the timer, which would then
close the parallel switch and then open it a short time later, and then
the motor switch, which would still be closed, could signal the end of
the cycle.
But, I thought I'd ask around and see if a simpler option was available.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
9:47 a.m.
On 12/7/2022 11:28 AM, Mike Stein via cctalk wrote:
I don't suppose there's an extra NC contact on
the motor switch/relay? If
so, a relay would do, otherwise two relays.
Sadly, no relay at all.
Since I was afraid of being off topic on the list, I hesitated to annoy
folks with too much detail, but it's unfair to those helping, so my
apologies.
The device in question is a 1960's era NuTone 8 note door chime
(doorbell). I don't know the exact model, but here are some links to
similar units:
https://www.youtube.com/watch?v=kbOVmMVrSTg
http://northsideforyourhome.squarespace.com/nutone-vintage-door-chime/nuton…
I admit I grew up in a later period and I have lived under a rock for
part of my life, so I did not know such cool devices were once sold.
If you can excuse the terrible narration, I put a small video together
to go over the unit, since I'd never seen such a cool piece of kit
before (living under the rock, so to speak).
https://youtu.be/HhGMhiAjmRU
The motor in question is a 3.6RPM "clock" motor, as far as I can tell.
It runs the "program", and the front doorbell switch engages the motor
momentarily to start the process.
I came upon this slice of home ownership by way of my sister and brother
in law, who hosted thanksgiving at their "new to them" home, which looks
to have not been renovated since it was built in the early 1970's. This
chime, in addition to an 8 room NuTone intercom system, are installed in
the home to this day. All of us think the system is impressive and must
be kept in the home. It actually took us a while to find this, as I
offhandedly commented we had to knock on the door since the lighted
doorbell didn't seem to do anything, which prompted BIL to note they had
lived there for a month and had yet to find the door bell in the home
(the lighted front button heavily suggested in operating unit
somewhere). We finally found it in the entryway, disguised as a part of
the Intercom system (made by the same company). We were unsuccessful in
diagnosing the issue in the moment, but I was able to take the unit home
to work on it.
As the video notes, I was able to determine and address the immediate
issue, but I notice the timing issue I wanted to solve it before
returning the unit. The video was mainly to explain to my sister and
BIL what had been wrong with the unit.
Given the nature of the unit, the switch has to remain a NO SPST, and
I'd really prefer to not rewire the switch and disconnect it from the
24VAC, since some buttons assume they are being driven with 24VAC. I
also prefer not to make any non removable changes to the unit. I
figured adding something to the terminals is easily removeable and thus
fair game.
It works as-is, but I can see people tapping the button too fast and
then my BIL deciding to replace the unit after annoying friends or
missing packages.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
10:06 a.m.
Just glue the contactor thingy back onto the motor spindle. Done.
Back to vintage computers.
On Wed, Dec 7, 2022, 9:47 AM Jim Brain via cctalk <cctalk(a)classiccmp.org>
wrote:
On 12/7/2022 11:28 AM, Mike Stein via cctalk wrote:
I don't suppose there's an extra NC
contact on the motor switch/relay? If
so, a relay would do, otherwise two relays.
Sadly, no relay at all.
Since I was afraid of being off topic on the list, I hesitated to annoy
folks with too much detail, but it's unfair to those helping, so my
apologies.
The device in question is a 1960's era NuTone 8 note door chime
(doorbell). I don't know the exact model, but here are some links to
similar units:
https://www.youtube.com/watch?v=kbOVmMVrSTg
http://northsideforyourhome.squarespace.com/nutone-vintage-door-chime/nuton…
I admit I grew up in a later period and I have lived under a rock for
part of my life, so I did not know such cool devices were once sold.
If you can excuse the terrible narration, I put a small video together
to go over the unit, since I'd never seen such a cool piece of kit
before (living under the rock, so to speak).
https://youtu.be/HhGMhiAjmRU
The motor in question is a 3.6RPM "clock" motor, as far as I can tell.
It runs the "program", and the front doorbell switch engages the motor
momentarily to start the process.
I came upon this slice of home ownership by way of my sister and brother
in law, who hosted thanksgiving at their "new to them" home, which looks
to have not been renovated since it was built in the early 1970's. This
chime, in addition to an 8 room NuTone intercom system, are installed in
the home to this day. All of us think the system is impressive and must
be kept in the home. It actually took us a while to find this, as I
offhandedly commented we had to knock on the door since the lighted
doorbell didn't seem to do anything, which prompted BIL to note they had
lived there for a month and had yet to find the door bell in the home
(the lighted front button heavily suggested in operating unit
somewhere). We finally found it in the entryway, disguised as a part of
the Intercom system (made by the same company). We were unsuccessful in
diagnosing the issue in the moment, but I was able to take the unit home
to work on it.
As the video notes, I was able to determine and address the immediate
issue, but I notice the timing issue I wanted to solve it before
returning the unit. The video was mainly to explain to my sister and
BIL what had been wrong with the unit.
Given the nature of the unit, the switch has to remain a NO SPST, and
I'd really prefer to not rewire the switch and disconnect it from the
24VAC, since some buttons assume they are being driven with 24VAC. I
also prefer not to make any non removable changes to the unit. I
figured adding something to the terminals is easily removeable and thus
fair game.
It works as-is, but I can see people tapping the button too fast and
then my BIL deciding to replace the unit after annoying friends or
missing packages.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
8:46 p.m.
On 12/7/2022 12:06 PM, Sellam Abraham via cctalk wrote:
Just glue the contactor thingy back onto the motor
spindle. Done.
Not done, as that's not the concern I am trying to address. I realize
my posting is not fully on topic, but if you are annoyed, just don't
respond and delete.
Jim
10:12 a.m.
On Wed, Dec 7, 2022 at 12:47 PM Jim Brain via cctalk <cctalk(a)classiccmp.org>
wrote:
On 12/7/2022 11:28 AM, Mike Stein via cctalk wrote:
Given the constraints, I would use a time-delay relay like this, which will
hold the relay for X amount of time after the input is released:
https://www.zoro.com/dayton-encapsulated-timer-relay-1a-solid-state-5wml4/i…
That one wants a contact closure for the input it appears, but there are
other ones that take AC and DC inputs instead.
Pat
I don't suppose there's an extra NC
contact on the motor switch/relay? If
so, a relay would do, otherwise two relays.
Sadly, no relay at all.
Since I was afraid of being off topic on the list, I hesitated to annoy
folks with too much detail, but it's unfair to those helping, so my
apologies.
The device in question is a 1960's era NuTone 8 note door chime
(doorbell). I don't know the exact model, but here are some links to
similar units:
527
days inactive
528
days old
8 comments
5 participants
participants (5)
-
Anders Nelson -
Jim Brain -
Mike Stein -
Patrick Finnegan -
Sellam Abraham