This light sensitive switch is built with transistors and other semiconductor devices. This switch operated light is designed to be connected directly to the voltage network, eliminating the low voltage source.
This circuit turn on a light after dark comes, and disconnects when light comes again.
A digital multimeter K thermocouple interface can be made using this circuit diagram. Type K thermocouples has a wide range of temperature, is used in many temperature applications from cryogenic applications to analyze the exhaust gases of jet engines. Described circuit converts the output signal of the thermocouple into a DC voltage of 10 mV slope / ° C, signal that can be applied to a multimeter or a computer.