This circuit was found in an Electronic Design. It makes use of a relaxation oscillator to trigger an SCR and two relays. The circuit operates at frequencies of 12 to 180 cycles per minute.
A frequency divider for digital signals can be constructed based on a single 4018 integrated...
This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern...
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. More...