This 1-transistor circuit for currents up to 50 mA was found in the August 1974 Radio Electronics magazine. The transformer is 50 to 200 mA.
This two-color LED indicator was found in a Popular Electronics from the 90's. The transistor...
This circuit was found in a Radio Electronics from the 90's. It provides lower frequency signals from...
This monostable circuit uses one of the two flip-flops available on the CMOS 4098 integrated...