This circuit uses a dual-gate MOSFET, a rare component today. We found it in American documentation from the 1980s. The rest of the components are common.
This triac circuit was taken from an article in the July 1970 Radio Electronics magazine. Note the...
Signals ranging from a few millivolts to a few volts can be used to excite a relay with this...
This circuit was found in American documentation from the 90's. The transformer determines the...