This circuit, which can use the 4011 or 4001, was found in documentation from the 90s. The load depends on the transistor used, and the power supply must be isolated.
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...