B21126E)
This circuit was taken from an old Popular Electronics. The circuit can have its frequency changed from an external signal. The center frequency is given by C1.
This special effect circuit with LEDs using the 4017 was obtained in a 1982 publication. LEDs are...
T This circuit produces an audible signal when someone touches the sensor, or even approaches. The...
This transmitter operates in the 80-meter range, around 3.5 MHz, with an exact frequency value...