This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222 can be used. The stabilizing diodes can be 1N4148.
This circuit allows you to simulate an analog telephone line for the repair and testing of...
High voltage electrolytic capacitors can be recovered by applying high voltage to their terminals. This...
In addition to keeping a battery constantly charged, this circuit only lights lamps when it is...