This circuit uses a capacitor that depends on the frequency of the crystal. We found it in a 1967 documentation. The maximum frequency is around 100 kHz.
Found in an Electronics World of 1966 this circuit is intended for use with a microphone as an...
This simple power source with only one transistor can be used in the laboratory, without overload...
This circuit, found in 2002 documentation, triggers LEDs when a phone call is received. The LEDs...