Found in a 303 Circuits from the 90's this circuit can use the lowest current range of a common multimeter. The circuit can measure currents as low as 100 pA.
This low frequency oscillator with an operational amplifier of type 741 has adjustment of the mark...
This circuit was found in a Popular Electronics from the 90s. Transistors are general purpose...
The AT21CS11 memory device offers an extended voltage range to accommodate lithium-ion battery...