This circuit was found in a 1992 publication. What it does is to light an external lamp when it gets dark. The trigger point adjustment is made in a potentiometer or trimpot and the sensor is a common LDR.
This general purpose circuit was found in a Popular Electronics. It is intended for detecting the...
May 2017 - Vishay's new AC0x..CS series safety wirewound resistors can now be obtained from Mouser...
We found this circuit in an Argentine documentation from 1973. The transistor admits a more modern...