This circuit was obtained from an American documentation from 1968. The current depends on the operational, observing that the circuit uses a symmetrical power supply.
Suggested by Hughes in 1968 documentation, this circuit makes use of a transistor matched pair and...
This circuit was found in a Hands On Electronics from the 80's. The circuit emits an audible alert...
Due to its low working voltage, this circuit of an old EDN can be associated with a...