Multimeter is widely used entry level test/measure tool. And is the hot topic in comments. While, in my opinion, the voltage tester is the first test tools for most electronic or electrical engineer. I have lost my first votage test long ago. It is one flat head screwdriver as well, is broken one day and no longer functional.

Here is what the voltage tester looks like.

The voltage shall be used safely according to this picture. The tip head touch the electrified object and the other end shall be touched by tip of one finger. The maximum safety voltage is 500V, and is not accurate below 60V.

The priciple is simple, one Mega ohms resistor and one small neon nixie tube are key components. The resistor restrict the leakage current to several mA , which is enough to drive the nixie tube when electricity cirtuit is closed. The nixie tube acts as fuse as the same time, it blows off if overvoltage.

The voltage tester is gift from my school classmate . We share same fancy probing sockets in classroom. He share his spare one with me. By when I still do not understand fully what safety means.

It is stronly recommended that everyone shall have the voltage tester before changing lighting bulb or change wall-mounted sockets or switches.

It is not rare that the outer metal-clad case of electrical instrument or desktop computer is energized if grounding wire is not properly connected. For some precise instrument, such electro-magnetic effect can spoil the test results.

I have used one voltage tester to find out one desktop computer is wrongly energized before I am electro-shocked.

Now I have new voltage testers with upgraded functions.

Some sore of like https://www.element14.com/community/roadTests/2240/l/Multicomp-Pro-Non-Contact-Voltage-Tester.

Here is the picture I used now, the one on the right is new with many functions.

Here is the botton on top shall be touched while testing. This voltage is sensitive, it can detect the electromagnatic field by 220V wire on the wall. But the LCD panel can give rough voltage level it detected. Here is the demo,

• The socket for plug is not energized. The live wire is dead not being energized, while there are inductive voltage on the GND and Earth wire.The electrical system is not so safe and clean.

• The socked is energized. Not the live wire is energized and the voltage indicator on lcd panel reach top of 220V when top botton touched by finger. The video is not stable, since it is shot by left hand.

This voltage tester gives quick measure to check whether the electrical wire is safe for instruments. Of course, that is definitely important in fixing lighting and wires.

Multimeter is widely used entry level test/measure tool. And is the hot topic in comments. While, in my opinion, the voltage tester is the first test tools for most electronic or electrical engineer. I have lost my first votage test long ago. It is one flat head screwdriver as well, is broken one day and no longer functional.

Here is what the voltage tester looks like.

The voltage shall be used safely according to this picture. The tip head touch the electrified object and the other end shall be touched by tip of one finger. The maximum safety voltage is 500V, and is not accurate below 60V.

The priciple is simple, one Mega ohms resistor and one small neon nixie tube are key components. The resistor restrict the leakage current to several mA , which is enough to drive the nixie tube when electricity cirtuit is closed. The nixie tube acts as fuse as the same time, it blows off if overvoltage.

The voltage tester is gift from my school classmate . We share same fancy probing sockets in classroom. He share his spare one with me. By when I still do not understand fully what safety means.

It is stronly recommended that everyone shall have the voltage tester before changing lighting bulb or change wall-mounted sockets or switches.

It is not rare that the outer metal-clad case of electrical instrument or desktop computer is energized if grounding wire is not properly connected. For some precise instrument, such electro-magnetic effect can spoil the test results.

I have used one voltage tester to find out one desktop computer is wrongly energized before I am electro-shocked.

Now I have new voltage testers with upgraded functions.

Some sore of like https://www.element14.com/community/roadTests/2240/l/Multicomp-Pro-Non-Contact-Voltage-Tester.

Here is the picture I used now, the one on the right is new with many functions.

Here is the botton on top shall be touched while testing. This voltage is sensitive, it can detect the electromagnatic field by 220V wire on the wall. But the LCD panel can give rough voltage level it detected. Here is the demo,

• The socket for plug is not energized. The live wire is dead not being energized, while there are inductive voltage on the GND and Earth wire.The electrical system is not so safe and clean.

• The socked is energized. Not the live wire is energized and the voltage indicator on lcd panel reach top of 220V when top botton touched by finger. The video is not stable, since it is shot by left hand.

This voltage tester gives quick measure to check whether the electrical wire is safe for instruments. Of course, that is definitely important in fixing lighting and wires.