This electric field detector circuit is a very useful project to detect electric fields around AC wire, AC socket etc. The circuit is very effective to detect AC voltage in wires without touching the wire with any AC meter and very useful for those who work with AC or mains voltages.
The uses of AC wires are now very common in our home, offices and workplaces. Many times these wires get damaged from inside due to which the whole system stop working. These wires get damaged due to their aging or short circuits etc. Our eyes cannot see these inside damages so we cannot able to detect that from where the wire is broken. So by checking the wires with this device can detect the inside damages in these wires.
The circuit is simple to build and using only few components which are a CA3140 opamp IC three resistors and one LED. The LED is used as an indicator for electric filed. The circuit is quite sensitive and can detect AC mains from a foot away. The sensitivity can be increase or decrease by increasing or decreasing the length of the antenna wire. The operating voltage of the circuit is 9 to 12V DC.
For further enhancing the circuit a buzzer or a relay switch can also be connected between pin6 and ground.