I just meant I wanted relay turn-on to be between 49v-51v. I wasn't worried about relay turn-off voltage because I planned to manually reset it.

That will change things a little. What that says if the voltage exceeds about 50 volts the relay will turn on and you want the relay to remain On until you provide a manual reset so what we would say is I want the relay to Latch at about 50 volts and remain latched until I reset it. That will change things but just a little. Pushing a normally closed reset button will unlatch the relay until the process repeats.

Ron

 

I wasn't worried about relay turn-off voltage because I planned to manually reset it.

Well I need to worry about it.

So what will be the minimum and maximum voltage when you reset the relay?

I assume you want it so that the relay can't turned off/reset if the voltage is above 50V (?).

 

Well I need to worry about it.

So what will be the minimum and maximum voltage when you reset the relay?

I assume you want it so that the relay can't turned off/reset if the voltage is above 50V (?).

The reset was planned to happen by just disconnecting the whole system which would have caused the relay to unlatch. (trying to use the terminology Reloadron offered)

I assumed that if the system was connected while voltage was above that level the relay would just latch immediately upon connecting which would be totally fine.

 

The reset was planned to happen by just disconnecting the whole system which would have caused the relay to unlatch. (trying to use the terminology Reloadron offered)

I assumed that if the system was connected while voltage was above that level the relay would just latch immediately upon connecting which would be totally fine.

Okay.
Then the circuit I posted in post #19 should work for you.

 

Crutschow. Thank you for 19. I'm studying "electrical engineering" at Khan Academy to learn enough to be able to follow that circuit.

 

Crutschow. Thank you for 19. I'm studying "electrical engineering" at Khan Academy to learn enough to be able to follow that circuit.

For that you will need to fully understand the operation of the TL431 from its data sheet.