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 circuit was found in July 1986 Radio Electronics magazine. The maximum current is 1.5 A. The...
This circuit activates 5 LEDs according to the level of the analog input signal and can be used...
This circuit is from an old American documentation and its use in motorcycles with 12 V is...