Relay Name?

Thread Starter

Alex-Bell-Alert

Joined Nov 2, 2021
1
Hi, I'm looking for a relay that performs the following function, but I need to know the technical name for it so I can purchase.

I'm looking for a relay that will energize a circuit for perhaps 5 seconds (to sound an alert) when it receives power (the door is open), however the relay will still be powered because the door is still open. Once the door closes, the relay will reset. Then once the door opens again, the alert cycle starts again. Relay coil needs to operate on approx 10 VAC or 18 volts DC.

Any help in identifying the type is appreciated!
 

Reloadron

Joined Jan 15, 2015
7,501
Hi, I'm looking for a relay that performs the following function, but I need to know the technical name for it so I can purchase.

I'm looking for a relay that will energize a circuit for perhaps 5 seconds (to sound an alert) when it receives power (the door is open), however the relay will still be powered because the door is still open. Once the door closes, the relay will reset. Then once the door opens again, the alert cycle starts again. Relay coil needs to operate on approx 10 VAC or 18 volts DC.

Any help in identifying the type is appreciated!
You may want to give this a read about time delay relays as they have a few flavors to choose from. Each definition includes a pictorial.

Ron
 

MisterBill2

Joined Jan 23, 2018
18,167
It would be an interval relay, and actually you can create a similar function with the DC relay by having a fairly large capacitor in series with it, so that the charging current engages the relay until the capacitor charges and the charging current drops. You will also need a resistor across the capacitor so that it will discharge to be ready for the next cycle. This is not the most precise scheme but it can work and it is very simple.
 
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