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Joined: Feb 2013
Posts: 264
Potseal Offline OP
Member
Looking for a simple relay that I can use in a circuit to create a brief delay and then reset itself.
The circumstances are as follows; a heavily used automatic door with a prox card entry and a push button exit. The electric strike is fail-safe. The door opener is powered by a pneumatic opener. The problem is that the door sometimes pushes against the strike before it can release. After several adjustments it has been determined the best solution would be a 1 sec delay on the pneumatic opener to give the strike a head start. Any suggestions? Thank-you.


A malfunction at the junction
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Dwayne
Joined: Jul 2004
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Places like Digikey have a pretty good assortment of time delay relays.


Greg Fretwell
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Greg Fretwell
Joined: Feb 2013
Posts: 264
Potseal Offline OP
Member
Yes, that is a bit pricey.

My boss is hoping I can find something simple and inexpensive as he expects this won't be the last door opener we need to modify.

I have been experimenting with an Omron H3CA since we have several sitting on the shelf which were salvaged from other projects. I can get it to do everything I want except auto reset after the delay.


A malfunction at the junction
--------------------------------------
Dwayne
Joined: Jul 2007
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"Live Awesome!" - Kevin Carosa
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As Sparky found, you can do better on the price. Digikey is like Grainger. They have everything but you pay for the convenience. Once you figure out what you need, the internet is your friend. A lot of this stuff shows up on Ebay pretty cheap.


Greg Fretwell
Joined: Aug 2008
Posts: 60
A
Member
Hi potseal, what do you mean with auto-reset?

You have your control voltage going to "high", after one second the relay should activate, and when the control voltage goes back to low the relay instantly should go off?
That's the basic "on-delay" type.
You can get this from your omron device by connecting term. 3+6 and using mode A.
If you only want a short impules from the relay, you Need mode F.
See the Manual here
http://www.farnell.com/datasheets/1500432.pdf

I don't know what distributors and relay manufacturers you use. In europe, I would go to farnell or RS Website and look for omron, tele, ABB, panasonic, eaton, finder... din-rail mount relays. They start at 40 bucks. Watch for UL or other markings you need for the US.

One second is long to wait for an automatic door, I would recommend an adjustable relay. Maybe it will work fine with 0.2-0.5 sec only.

Last edited by andey; 11/23/16 07:48 AM.
Joined: Sep 2011
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Last edited by ampherder; 11/23/16 12:45 PM.
Joined: Feb 2013
Posts: 264
Potseal Offline OP
Member
Originally Posted by andey
Hi potseal, what do you mean with auto-reset?

You have your control voltage going to "high", after one second the relay should activate, and when the control voltage goes back to low the relay instantly should go off?
That's the basic "on-delay" type.
You can get this from your omron device by connecting term. 3+6 and using mode A.
If you only want a short impules from the relay, you Need mode F.
See the Manual here
http://www.farnell.com/datasheets/1500432.pdf

I don't know what distributors and relay manufacturers you use. In europe, I would go to farnell or RS Website and look for omron, tele, ABB, panasonic, eaton, finder... din-rail mount relays. They start at 40 bucks. Watch for UL or other markings you need for the US.

One second is long to wait for an automatic door, I would recommend an adjustable relay. Maybe it will work fine with 0.2-0.5 sec only.


"Auto reset" refers to the ability to reset itself after it performs it's function. For the Omron H3CA in A mode it appears I would need a manual reset or power loss to reset it. There is another mode that uses a time-limit reset. Unfortunately that function appears to be for off delay only.


A malfunction at the junction
--------------------------------------
Dwayne
Joined: Feb 2013
Posts: 264
Potseal Offline OP
Member
Originally Posted by ampherder


I seen that one before. The price is appealing but it has a minimum 1.8 sec setting. A little too long for our purpose.


A malfunction at the junction
--------------------------------------
Dwayne
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