We found this circuit in the magazine Eletcronics Now of July 1994. The power supply is according to the relay and the transistor can be any general purpose one.
This second amplifier is based on the integrated LM108 and has a differential input. The resistor...
Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found...
In the figure we have the circuit of a bistable using two relays. We found this circuit in an...