Light Activated Relay Switches
This electronic kit is actually 3 separate electronic circuits that will enable you to open and close a switch (switch on/off) depending on the level of light that the circuit detects (using it's light detection component). You might be able to turn on a flood light when it gets dark, for example, or turn it off again when it gets bright out. The relay switching component means that almost any device can be switched/controlled by light sensitivity.
Light Activated Relay Switches Reviews: