Is there such thing as a relay that has an adjustable signal input. Like say its a normally closed relay and it open at 5 volts, or 3.7 volts or what ever you set it at. If there is suck a thing can someone hook me up with a link. thanks

 

not that i've seen but you can use a resistance calulator to make a resistor that you can put in like of your output wire to get a desired voltage. you can pic resistors up at radio shack.