relayresistance
I'd like to build the circuit detailed here, which calls for a 12V DC 260Ω resistance relay:
Looking at some relays, what consequence would using a 400Ω relay have? Would I be able to use one without a problem?
Unrelated: I believe it's a non-latching SPST NO relay that I need here, right? From what I understand, a SPDT can function as a SPST by ignoring one of the pins; is this correct?
I don't believe your application can be solved with the components you mention. Either you need switches that give a single pulse or a non-latching relay. My proposed solution is with a regular non-latching relay (and thus pin numbers may be wrong).
If the relay is rated for 120V, then my first attempt would look like this. The below is with a non-latching relay though.
simulate this circuit – Schematic created using CircuitLab
Every relay has a life expectancy... they are not infinite. You are saying that at 3 hertz you activate it a few million times, that is a lot of activations for a relay.
As you have not provided a part number, for illustrative purposes, I have used a generic one. The datasheet of your relay should have a graph like this one...
As you can see, in this relay particularly, the maximum life operations it can have no more than a million and a half operations...
That type of failure is normal in relays because the contact material starts wearing away with normal operation, and if you operate at the maximum rated load, as you can see in the table, the relay will have no more than 30,000 operating cycles.
I hope this information is clear enough.
Best Answer
The 400 ohm relay will stay closed longer. You should reduce the capacitor by about 260/400, so about 220uF in order to make the time similar.
Yes, you can just ignore the normally closed contact.