Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes out when it gets dark. The circuit can be adapted to use high-brightness white LEDs.
With this circuit it is possible to keep the current in an LED constant even if the supply voltage...
This circuit was suggested by Motorola in its manual of components for optoelectronics (1987)...
This sensitive circuit can be designed with FETs such as BF245 and MPF102. The sensor is a silicon...