This shield with full-wave triggering was found in the Radio Electronics Experimenter magazine of 1989. The Triac must be according to the load that must be controlled.
Suggested by Motorola documentation from the 1980s, this circuit makes use of MOSFETs of the time....
In the figure we have a small general-purpose amplifier with the LM386 integrated circuit and...
This circuit allows you to use a digital multimeter as a thermometer. The sensor is mounted in a...