The indicator for this circuit is a 0 to 1 mA milliammeter. The operational is from the 70s, when the circuit was published. Modern equivalent can be used.
This circuit is suitable for applications in medical, research and industrial equipment. The...
This circuit, found in a publication of the year 1968, uses a transformer to drive two power...
This 100-second timer was found in a 2000 Poptronics. The magazine no longer exists, but the...