This Circuit can compare the Light level in an area. It uses a PN Photodiode as the light sensor and IC CA3140 as voltage comparator. The circuit is ideal as the front end of burglar alarm circuits.

Here is a simple Temperature Sensor Circuit or Heat Sensor Circuit. This circuit uses very few and basic components which can be easily available, anyone can build it right away.

The multimeter is a measurement device most used by engineers and we use it in this temperature indicator circuit schematic. The temperature sensor is LM335 wich has a linear characteristic of 10mV / ...

Here’s a temperature detector system capable of remote temperature reading without transmission losses in the conditioning circuit. The IC AD590 (IC4) is used as a temperature transducer. This ...