DIY Non-Contact Voltage Detector




Introduction: DIY Non-Contact Voltage Detector

About: I am a 17 y/o kid. If you like my instructables do comment and tell your thoughts about them. Do see all of my instructables and a favourite will be greatly appreciated. Have a great day ahead...

Everyone gets tired of using those wires hanging out of your multimeter to detect any voltage is a wire or a circuit

But there is a way to it a Non-Contact Voltage Detector. Yeah that sounds neat and simple.

So, Let's make it with using only 4 Components. What !!! Only 4 Componrnts but How ??

If you want to know just make it ; )

Step 1: Gather the Components

As I told only 4 Components are needed for this project. The list of all the materials needed is below

  • Transistor [2N3904] (X2)
  • Resistor [220 Ohms] (X1)
  • LED (X1)

We will need some more things for this project -

  • 9V Battery Connector
  • Some Wires

Below are the tools that you will also need

  • Soldering Iron

And a ......

  • Glue Gun

Step 2: The Circuit

The whole Circuit that we will be making is in the image above with the Crystal Clear circuit diagram

Make sure you check it out. I am providing some tips for you to solder the Circuit -

  • Keep the wires from your components short so that they don't take up much space and can be enclosed in a bottle cap
  • You can take out one old Battery connector from a used up 9V Battery and directly solder it to the circuit to save space and some pennies too for your next project
  • Use your Fired up Soldering Iron carefully

Step 3: Enclosure

We will need something to protect our circuit from corrosion and to make it look nice too. So let's make an enclosure for it now (enclosure is something kinda Shell like Structure)

  • Take 2 Bottle Caps
  • Make a hole for the LED and some more holes for the Battery Connector's wires and the Open wire (from the transistor)
  • Take the LED and all the wires out of the holes
  • Fill the Caps with hot glue to Secure our Circuit and to make it strong too
  • Glue the 2 Caps together
  • Glue Battery Connector on the top of one cap and make a loop of wire on the top of other cap

With this our Non Contact Voltage Detector is Ready to go for some testing and some Detection.

Step 4: Testing Time

Our Non contact Voltage Detector is ready to go. Just Connect a 9V Battery and take it near some wire from the Socket

You will observe that the more nearer you go the Brighter the LED gets

This thing is going to ease your way out while checking any voltage in any wire or circuit without ripping off any of its insulation and the using the multimeter

RIP multimeter (atleast for this purpose)

Thanks for Vising my instructable

Do share your creation in the I made it Section below and ask any doubts freely in the Comment Section

Happy Making and....... Happy Detection [in this case] XD

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    Question 3 years ago on Step 2

    does it have to be a copper wire? My LED is always on

    Gagan jain
    Gagan jain

    Answer 3 years ago

    I don't think so that it needs to be a copper wire specifically but here is a tip, crack your device open and check whether any of the two open wires are in contact with each other. If this is happening then try moving them away from each other and if possible while soldering the components, you can use heat shrinks.
    I hope this solved your queries and feel free to ask any more questions


    4 years ago

    Actually what you made is an open base darlington transistor amp with extremely high gain. And that is good as long as you warn people that just because it doesn't light up doesn't necessarily mean there is no live voltage. JMHO