We found this circuit in an old Popular Electronics. The circuit is experimental, driving an LED from signals applied to the LDRs. The power supply does not have to be symmetrical.
This circuit was found in a 1966 publication using a microwave transistor of the time. The circuit...
The integrated circuit used in this application is the National Semiconductor's LM2907, the...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...