One of my projects has a pic turning an N-Chan MOSFET on which then connects a ground and turns a relay on.
I was told that I must have a relay with a diode in it. To prevent EMI from coming back and burning my transistor up. I can do that.
However I looked at my bag of relays and noticed somthing... They don't have a resistor symbol across the coil like others do, and they dont have the diode symbol... Instead the have a long rectangle. Um... What does THAT mean ?
There are also the words "Negative Spike Suppresion" printed on the bottom. They are Beuler relays.
I did some reading and found that De-Spiking can occur from a diode or a resistor... They say the diode is better, but the resistor can handle more abuse.
I am dumb and dont know how to use the diode check on my DMM (it says .033V when I measure across the coil) and the resistance is 66ohm. But I think if there were a larger resistor in there then that of the coil, I wouldnt be able to read it. no ?
Any way to tell whats going on ?
I was told that I must have a relay with a diode in it. To prevent EMI from coming back and burning my transistor up. I can do that.
However I looked at my bag of relays and noticed somthing... They don't have a resistor symbol across the coil like others do, and they dont have the diode symbol... Instead the have a long rectangle. Um... What does THAT mean ?
There are also the words "Negative Spike Suppresion" printed on the bottom. They are Beuler relays.
I did some reading and found that De-Spiking can occur from a diode or a resistor... They say the diode is better, but the resistor can handle more abuse.
I am dumb and dont know how to use the diode check on my DMM (it says .033V when I measure across the coil) and the resistance is 66ohm. But I think if there were a larger resistor in there then that of the coil, I wouldnt be able to read it. no ?
Any way to tell whats going on ?