I’ve found some interesting schematic of load cell amplifier. As we know, load cell amplifier is pretty expensive with fair price range of 100-300 USD. […]


Touch alarm circuit is widely used for security, which is installed on the door. The advantages of this alarm is because the cost is cheap […]

A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.

The following circuit diagrams are tone detector circuit diagrams which also known as sound activated switch circuit. Actually, these circuits? use microntroller for switching because […]

This is the basic dark and light sensor which using photoresistor as sensing component. The transistor act like as a switch, when the “switch” in […]

This is the color detector / sensor circuit diagram. This circuit will sense eight colors that are: green, red and blue (as primary colours); magenta, […]

Turn on and turn off your electrical devices using touch switch, so you can “play” your electronic devices more fun.. 🙂 . Touch switch don’t […]

Flame, gas and smoke detector for fire alarm. You can combine this circuit with alarm circuit. The output will be the relay which switch on […]

Here is the circuit diagram of ultrasonic sensor switch. There are many methods of wireless switching such as by using infrared, AM/FM signal, bluetooth, etc. […]