Found on a 1969 EDN this circuit switches a current from a digital control signal. The impedance of the circuit ON is approximately 10 ohms. Modern equivalent transistors may be used.
This bistable or flip-flop is triggered by a negative pulse applied to the collector of the...
This circuit is old, but it can be easily implemented with TIP42 transistors and a 6 + 6 V or 9 +...
This circuit is from the LM111 manual of the 1980s. The component no longer exists, but...