This circuit is based on the light comparison of two LDR sensors. We found it in a 90s Popular Electronics. The transistor must be according to the indicator or load being driven.
This circuit is from an English publication from 1965. The transistors used are rare, however, they...
This low voltage circuit was found in the November 1960 Radio Electronics magazine announcing new...
We found this circuit in a 2003 publication. The indicated coil is for capturing the signals in an...