This circuit consists of an improved version of the CIR5892, using two transistors and adjusting the operating point. The transistors can be the BC548.
This circuit is like the previous one except that it can be triggered electronically. The circuit is...
Found in 90s Radio Electronics, this audio indicator makes use of an integrated circuit that is...
Found in the October 1992 Radio Electronics magazine, this oscillator is controlled by switch S1....