This type of configuration can be seen elsewhere in this section. This is from a 1965 General Electric Hobby Manual. The circuit applies to most modern triacs.
We found this circuit in an 80's Radio Electronics. The circuit uses a PTC sensor and an LED...
In this circuit a 12 V lamp or LED blinks with the music signal applied to the input. R depends on...
Using a period sensor, this circuit was found in the February 1986 issue of Radio Electronics...