This circuit drives a load with a delay given by the RC timing components. The circuit is from 1970s documentation. The diode is a general-purpose type.
This circuit can be used to control loads up to 500 mA from the outputs of microcontrollers such...
This circuit with transistors in parallel was found in a Radio Electronics of August 1952....
This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the...