The frequency of this circuit depends on C1 and, for the indicated values, it is 1 kHz. Equivalent operational amplifiers can be used, and the power supply must be symmetrical.
This well-crafted speed game setup for two competitors was found in a 1998 Poptronics. The circuit...
September 2017 - Microchip is making available through Mouser Electronics the ARM Cortex® M +...
This power source with silicon diodes at a time when valves were still used was found in Radio...