The purpose of this circuit is only to increase the input resistance of a multimeter, since there is no voltage gain. The batteries are 9 V and operational equivalents can be used.
Simple timers can be designed using inverters or any other gate that can be connected as inverter. Figure...
Found in the Encyclopedia of Electronic Circuits volume 5 from 1995, this circuit uses a...
Found in a 1980s telecommunications documentation, the circuit presented acts as a product...