This amplified speaker is from a Radio Electronics from September 1988. The power integrated circuit is from that time and the other components are still common today.
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...