This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
This circuit was found in a 1973’s Japanese magazine. It uses transistors of the time and is...
September 2016 - It can be purchased from Mouser Electornics the iW1818 of Dialog Semiconductor, a...
This circuit converts a resistance in the range between 1 k ohm and 1 MΩ to a signal in a...