Inside a generic voltage detector stick

I have 1 with buzzer and led and a seperate led for a 'torch' Think I have used it once, paid about £2 for it.

Alan King

The "heartbeat" pulses were added after Fluke had issues with another product powering off silently when dropped. A clear indication of readiness for use was essential. Clive demonstrates a similar phenomenon in the video: drop the unit on one end, the batteries shift and either temporarily or permanently disconnect.

Mike Page

It's amazing to me how many different models are out there and how differently they work from each other. My go-to volt stick is the Fluke 1AC II. It's sensitive enough to discern between hot and neutral slots in US outlets (many models ring from inches away - useless...) and it will ring without touching it most of the time, which is useful for identifying circuits at a distance. It also pulses the LED to let you know when it's on and has an auto shut-off. Another model I've used which is good is from a company called Santronics, which makes theirs here in the US. Their 3000 Ultimate model is functionally very good, but the plastic is less impressive than on the Fluke.

Peter Argyropoulos

So do the guidelines (such as TB 118 - Safe electrical isolation of gas appliances). When paired with a proving unit, a two-pole tester should be very reliable.

Mike Page

It would depend on the circuitry in the unit. But a longer antenna would definitely be a good call.

Big Clive

I've never (& will never likely) trust a non-contact tester to tell me mains is off. I like testing by connecting to the line & ground with a REAL tester.

Scott Miller

Thanks, Clive. My next project!! I was getting bored. Cheers

Chuck Kirchner

A similar way to test a neon bulb (or a neon mains tester screwdriver): Stand on carpet, touch one lead of the neon or screwdriver tip against something earthed (e.g. bare metal on a radiator) and stroke one foot against the carpet.

Seán Byrne

With all "non-contact" voltage detectors you're sensing electric field. Being physically nearer Neutral than Live means the field is weaker with respect to Earth (which is you: your hand is the COM terminal). So what's important is having a reliable indication threshold.

Mike Page

Oooh now this is my wheelhouse! Kewstick Duo is my design. More sophisticated, but still affordable. People like the noise and the attenuation button.

Mike Page

How hard would it to be to convert a cheap ebay one (less than £5 shipped) to a "ghost detector", would it be as simple as adding another transistor and longer antenna?

The old neon screwdrivers did have a resistor inline as well. The neon only drops 90V so the resistor is what limits the current to safe levels.

adrian

How do the versions that differentiate between Live and Neutral work?

Steve Pritchard

Interesting Clive, I've had a Fluke stick for years, it beeps as well as lights up the end. It's great for checking fuses in 13 amp plugs.

Here's a good way to test the tester.... rub the tip on your jeans. It will trigger the detector.

I had the neon bulb version. Not sure where it went. Dangerous if you think about it, Hold one lead and touch the other to the circuit and hope the neon lamp doesn't short or arc over.

George Cohn

Wow. What a coincidence. I literally had one of these delivered yesterday, and was thinking "I wonder how they work, I think I'll ask Clive to see if he will make a video about one".

Steve Pritchard

I still have the Radio Shack UK kit for a "mains tester" this was from the 1990s, it was in the discount bin. The kit was like you said very simple and a small rectangular black housing that may have a had a 9v battery. Aside- in the late 1980s I bought a Maplin kit for an ioniser, I should find it am send you a photo. My approach to live mains was always Test it LIVE Test it DEAD "Go ahead" and get someone else to touch it first. John

John Harrison

They work by reference to ground. For an isolated supply it may work if there is enough wiring in the vicinity of a ground plane like trunking, conduit or tray.

Big Clive

I haven't had the chance to try but will they work if the neutral bond is lifted on let's say a small control transformer?

Aaron Nadler

Your explanation of the three different approaches was very informative, thanks BC. But it does look suspiciously like a 'floating candle' Harry Potter Wizardry Detector! Just the thing for Ghostober.

Ymir the Frost Giant

Can these also be used to detect dirty dancing? Or bad John Tra-VOLTa tribute acts? I admit I haven't watched it yet - just about to...

Ymir the Frost Giant