This sequential circuit of LEDs was found in a Popular Electronics from the 90s. The circuit can be programmed and an adaptation consists of using optical couplers to drive power loads.
This circuit generates 50, 100 and 200 Hz signals from a 3.2768 MHz crystal and has outputs...
This circuit allows frequencies between 1.8 and 30 MHz to pass. Data for the coils is provided next to...
The automatic heating system sensor is a diode placed in a waterproof tube as shown in the figure....