This circuit controls a heating element using a triac. Triac must be fitted with a heat sink. We find it in an American documentation from the 80s.
In this circuit of a 1970s publication, data from the coil to oscillate at the desired frequency...
This circuit is from 2005 documentation. It automatically starts an irrigation pump when the...
The figure shows how to use a CMOS amplifier as a crystal-controlled oscillator. The circuit is...