Pulse Relay

[Jeff_L]

I'm not sure if "Pulse Relay" is the correct terminology or not, and I'm sure I could figure out how to do it with a PLC. However, does anyone know of a stand alone relay that will cycle a predetermined amount of time when it receives a signal? Basically cycle the power to the item you are controlling on a constant basis until the signal it is receiving goes away? Such as on for 3 minutes, off for 3 minutes, one for 3 minutes, then off again. And keep doing this until it's source signal which triggered the cycle goes away?

 

[MEP001]

There are relays that do this, for example compressor drain solenoids that have a built-in timer, but they cycle when they're powered up and don't have a control input. Here's a "repeat cycle" relay from Grainger:

http://www.grainger.com/Grainger/items/1EGD1

 

[Jeff_L]

Thanks MEP, that's getting just as costly as my PLC. Guess I'll have to crack into the programming and put it together. Probably a better idea to use the PLC instead since I can modify the timer and count the times, etc..

 

[MEP001]

Yes, plus the cheapest Logo has four outputs and 8 inputs, so you have many times the available uses that you do from a single relay.

 

[Jeff_L]

Yeah, I couldn't figure out a way to buy the one you've been discussing on this forum. Maybe I just didn't poke around the website enough. I ended up going with the TECO SG2-20KR-A model. It's nice and comes with software to allow you to build in ladder or function block mode. I just haven't really implemented it yet, other than being able to turn my workshop lights on and off remotely by VPNing into my workshop computer and going into the running program. I built a simple ladder program today and have been running it in simulate mode and so far it's doing what I want it to do, which is to cycle power to a device every 2 minutes or whatever I want to set it for.

The model I have is a 110v power model, I'm trying to read through the manual to see if I just need to power it via 110v but can run 24v through the I/O ports on it, for that's what I'm using to go to the contactor for the pump I want to cycle.