This 28 year old Stanley Vemco automatic gate uses mechanical relays. The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can hear a
relay click with no problem, then the gate opens. Just before the gate is
fully open, it enables a sensor switch which interrupts power to the motor
relay. Then, you can hear one of the relays make a chattering noise which
decays in about two seconds. The same thing happens when the gate closes. It
seems to have gotten louder over the years. Since the entire circuit is AC,

"David Farber" wrote in message
...
This 28 year old Stanley Vemco automatic gate uses mechanical relays. The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can hear
a
relay click with no problem, then the gate opens. Just before the gate is
fully open, it enables a sensor switch which interrupts power to the motor
relay. Then, you can hear one of the relays make a chattering noise which
decays in about two seconds. The same thing happens when the gate closes.
It
seems to have gotten louder over the years. Since the entire circuit is
AC,



Sorry about this incomplete message. It was erroneously sent. I think the
solution will be to replace the noisy relays with new ones.

--
David Farber
David Farber's Service Center
L.A., CA

On Jun 21, 2:53 pm, "David Farber" wrote:

Sorry about this incomplete message. It was erroneously sent. I think the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA

wrote in message
oups.com...
On Jun 21, 2:53 pm, "David Farber" wrote:

Sorry about this incomplete message. It was erroneously sent. I think the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA


Might be worth checking to see if there's a diode or rectifier bridge in
there. A shorted diode could cause AC to be fed to relay coils expecting DC
which will make them chatter or buzz.

"James Sweet" wrote in message
news:zWTei.71$ss5.68@trndny03...

wrote in message
oups.com...
On Jun 21, 2:53 pm, "David Farber" wrote:

Sorry about this incomplete message. It was erroneously sent. I think
the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA


Might be worth checking to see if there's a diode or rectifier bridge in
there. A shorted diode could cause AC to be fed to relay coils expecting
DC
which will make them chatter or buzz.



I dismantled this thing last year. There are only switches and relays. But
now that you mention it, maybe some of the relays were improperly replaced
with dc relays or the diodes are missing? I'm not the original person
working on this controller.

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA

On Fri, 22 Jun 2007 17:47:11 GMT, "James Sweet"
wrote:


wrote in message
roups.com...
On Jun 21, 2:53 pm, "David Farber"
wrote:

Sorry about this incomplete message. It was erroneously sent. I
think the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA


Might be worth checking to see if there's a diode or rectifier bridge
in
there. A shorted diode could cause AC to be fed to relay coils
expecting DC
which will make them chatter or buzz.


It could also be due to, or exacerbated by, a dried out electrolytic
filter capacitor in the DC supply circuitry.

"Ross Herbert" wrote in message
...
On Fri, 22 Jun 2007 17:47:11 GMT, "James Sweet"
wrote:


wrote in message
roups.com...
On Jun 21, 2:53 pm, "David Farber"
wrote:

Sorry about this incomplete message. It was erroneously sent. I
think the
solution will be to replace the noisy relays with new ones.

That, it would. Stanley makes (made) good stuff, and 28 years ain't
nohow half-bad. If all it is is relays, count yourself lucky.

Peter Wieck
Wyncote, PA


Might be worth checking to see if there's a diode or rectifier bridge
in
there. A shorted diode could cause AC to be fed to relay coils
expecting DC
which will make them chatter or buzz.


It could also be due to, or exacerbated by, a dried out electrolytic
filter capacitor in the DC supply circuitry.

It occurred to me that if I posted the pictures of these relays, that it
would be easy for somebody that is more familiar with this type of equipment
would be able to tell me if these relays have AC or DC type coils:

http://www.pbase.com/mrfixit/image/81163240

http://www.pbase.com/mrfixit/image/81163242

http://www.pbase.com/mrfixit/image/81163244


Thanks for your reply.

--
David Farber
David Farber's Service Center
L.A., CA

070620 1248 - David Farber posted:

This 28 year old Stanley Vemco automatic gate uses mechanical relays. The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can hear a
relay click with no problem, then the gate opens. Just before the gate is
fully open, it enables a sensor switch which interrupts power to the motor
relay. Then, you can hear one of the relays make a chattering noise which
decays in about two seconds. The same thing happens when the gate closes. It
seems to have gotten louder over the years. Since the entire circuit is AC,



Relays work on a magnetic principle. When voltage is applied to the coil,
the is created a magnetic circuit the engages. The magnetic pole pieces
slam together. If there is a piece of dirt, or other foreign substance on
the surface of the magnetic circuit where the pieces slam together, they
will not engage properly, and with AC, the magnet will chatter. This is
very annoying, and the poles should be cleaned. Just take a look in the
relay and clean out any debris that has fallen into the magnetic circuit.

On Jun 20, 1:48 pm, "David Farber" wrote:
This 28 year old Stanley Vemco automatic gate uses mechanical relays. The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can hear a
relay click with no problem, then the gate opens. Just before the gate is
fully open, it enables a sensor switch which interrupts power to the motor
relay. Then, you can hear one of the relays make a chattering noise which
decays in about two seconds. The same thing happens when the gate closes. It
seems to have gotten louder over the years. Since the entire circuit is AC,

You've got a bad pair of contacts feeding the coil of one of the
relays. The chattering relay is probably not the one that is at
fault; the difficulty might well lie in that sensor switch. I've had
difficulties with magnetic reed switches in the past, and if there's
one there I would see about it. There may also be a bad connector
associated with the sensor switch. Find the wires that go to the
sensor switch and use a jumper across them to simulate the operation
of that switch. If the relays operate but do not chatter, then the
difficulty lies in the sensor switch or its wiring.

M Kinsler

"m kinsler" wrote in message
ps.com...
On Jun 20, 1:48 pm, "David Farber" wrote:
This 28 year old Stanley Vemco automatic gate uses mechanical relays.
The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can
hear a
relay click with no problem, then the gate opens. Just before the gate
is
fully open, it enables a sensor switch which interrupts power to the
motor
relay. Then, you can hear one of the relays make a chattering noise
which
decays in about two seconds. The same thing happens when the gate
closes. It
seems to have gotten louder over the years. Since the entire circuit is
AC,

You've got a bad pair of contacts feeding the coil of one of the
relays. The chattering relay is probably not the one that is at
fault; the difficulty might well lie in that sensor switch. I've had
difficulties with magnetic reed switches in the past, and if there's
one there I would see about it. There may also be a bad connector
associated with the sensor switch. Find the wires that go to the
sensor switch and use a jumper across them to simulate the operation
of that switch. If the relays operate but do not chatter, then the
difficulty lies in the sensor switch or its wiring.

M Kinsler


The sensor switches are regular microswitches. I'll do the jumper test and
see what happens.

Thanks for the good suggestion.

--
David Farber
David Farber's Service Center
L.A., CA

"m kinsler" wrote in message
ps.com...
On Jun 20, 1:48 pm, "David Farber" wrote:
This 28 year old Stanley Vemco automatic gate uses mechanical relays.
The
problem is that the relays are noisy when either the opening or closing
sensor switches are activated at the end of its travel. For example,
somebody runs over the air hose to begin the open operation. You can
hear a
relay click with no problem, then the gate opens. Just before the gate
is
fully open, it enables a sensor switch which interrupts power to the
motor
relay. Then, you can hear one of the relays make a chattering noise
which
decays in about two seconds. The same thing happens when the gate
closes. It
seems to have gotten louder over the years. Since the entire circuit is
AC,

You've got a bad pair of contacts feeding the coil of one of the
relays. The chattering relay is probably not the one that is at
fault; the difficulty might well lie in that sensor switch. I've had
difficulties with magnetic reed switches in the past, and if there's
one there I would see about it. There may also be a bad connector
associated with the sensor switch. Find the wires that go to the
sensor switch and use a jumper across them to simulate the operation
of that switch. If the relays operate but do not chatter, then the
difficulty lies in the sensor switch or its wiring.

M Kinsler


Now that I've added the motor circuits to the schematic, you will notice
that the coil in the B relay is in series with what looks suspiciously like
a motor start capacitor. Can this be correct?

http://www.pbase.com/image/81471200

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA