This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can be the TIC106 need not have a heatsink.
This circuit uses an optocoupler with a phototriac or optotriac to drive an external triac. The...
In the original version of a 1968 publication, this circuit uses BC109 transistors. However, the...
The purpose of this circuit is to monitor the output voltage of a power supply. The under and over...