Old automatic gate controller question.

It

AC,

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.

the

DC

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.

think the

in

expecting DC

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:

Thanks for your reply.

These relays are all designed to be energized by an AC source. The copper shunt at the end of the pole piece is characteristic of AC relays. Is there a 24 volt transformer anywhere in there and do all of the relays chatter, or just one?

David

there

or

Yes, there is a 24V transformer. The difficult part is figuring out which one(s) are chattering. They are not in a very convenient place to observe what's going on and all three of them are mounted side by side. I might need to extend the wires a bit so they can be moved into plain view and still have them electrically connected. Can you please explain in the picture of relay 1,

Thanks for your reply.

If you have a 24 volt supply then may I suggest you look for a rectifier or diode that has shorted and sending 24 volt ac instead of DC to the coil. those relays require DC volts if you're using voltages that low.

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.

"David Farber" wrote in message news: snipped-for-privacy@corp.supernews.com...

The picture would indicate to me that the contacts are rated for 11 amps with either a 120v AC source a 28v DC source. It is not obvious what the coil voltage is supposed to be. Relay 2 appears to have a 110vac coil and relay 3 a 24vac coil. These look remarkably clean for such an old unit.

David

it

copper

chatter,

which

observe

need

of

of,

coil.

As I found this unit, there is *no* dc power supply in this controller. One relay coil is connected directly to the 120VAC line voltage and is always on as long as the main power switch is on. All the other components are powered by the 24VAC. Those components are the two remaining relays, one self contained timer control device which delays the gate closing, and the contactor, which has two 24ACV solenoids that activate switches to enable the motor in either the forward or reverse direction.

Thanks for your reply.

The pictures are about two years old. The unit itself is located in a protected box and that probably has helped to preserve the looks of the components.

Thanks for your reply.

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

hear a

is

motor

which

closes. It

AC,

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

Thanks for the good suggestion.

ain't

bridge

electrolytic

it

equipment

The contact appears to be in good condition at least. Can't tell from the text whether it is AC or DC coil. The details appear to show the contact ratings only. Anything written on the other side of the coil?

Midtex 1522T200 - Online Components

Midtex 15523Q200 - Online Components

Midtex is now part of the Tyco brand stable but I can't locate the part numbers on their site. Have requested specifications from Tyco if available. Will post result.

PS. Since you say there is no DC power supply then it would appear that photo 1 also shows an ac coil relay.

Perhaps whoever worked on it before was replacing parts and not too picky about what types of relays were put in.

I have uploaded a schematic of the electronics which I drew from tracing all the wires. I'd like to know if anybody can find any mistakes in the wiring diagram.

Secondly, there is a bell hose that opens the gate from the inside of the garage and a key that opens the gate from the outside. There is a second hose whose sensor is not hooked up which runs underneath the gate when in the closed position. I think this is a safety factor in case somebody drives in and the gate starts to close and would prefer not having their car smashed. As a security precaution, I think it would be smart to have this second hose sensor only allowed to be activated if the gate is actually closing. Where would be the correct spot, assuming one exists, to insert the second hose sensor that would *only* open the gate if the gate is in the process of closing?

Thanks for your reply.

Tyco

picky

tracing all

wiring

the

second

when in

drives

this

actually

insert the

the

Yipes! All those uninsulated terminals look dangerous to me....

Drawing out schematics of relay equipment is an art in itself. You have to establish conventions (ie, moving and stationary contact sets, coil relationships and status of the total mechanism). You must draw the whole system when it is in a defined state, such as "gate closed", and then draw the state of each relay and its associated contacts in this condition, remembering that the moving and stationary contact springs must also be drawn to reflect the associated relay situation.

For example your notes say that Relay A is shown de-activated but the schematic is drawn such that its coil IS activated via the limit close switch (ie. the gate is closed). Also, the schematic shows the timer relay is activated from GND at C/9-3 (deactivated) via A/8-3 (deactivated) to 24Vac, yet the timer relay contact is shown as being open.

The schematic also shows the main power switch is ON and the B relay is activated. I assume those B contacts are supposed to be normally open when the relay is deactivated, so if this assumption is correct and the relay is drawn in its activated position, then the contacts should be drawn with the moving contact at the top being pulled towards the coil and making contact with the stationary contact. As drawn the contacts are shown as opening when the coil is activated but I assume you meant to draw it with the contacts making when the coil is activated.

Also, where is the motor connected and what voltage supply powers the motor?

Unless you can clearly define the status and show things as they really are in that condition, then it is difficult to work out how things are meant to work.

Having said that, your first effort is to be commended, considering you probably haven't had to do this sort of thing before.