This circuit was designed to power the previous circuits of the wireless sound system, but it can be used for other purposes. The circuit is from a Radio Electronics from August 1988.
This oscillator with crystal for overtone operation was found in an old American documentation. The coil...
In the figure we have a basic PLL circuit with the LM567 or equivalent. The circuit is from a 1977...
The A3906 integrated circuit from Allegro MicroSystems (www.allegro.com) consists of a single...