I Have been doing some experiments based on an LED replacement for the classic neon test screwdriver. the electrical test equipment of choice for do-it-yourselfers handyman, and Builder contractors who don't really want to spend much on electrical test gear, but want a basic indication of whether they're going to die when they touch a live wire. So this thing is very simple. It contains a Neen indicator and a one Meg Ohm resistor and I'll show you the inside of this because it is.

This one is a British compliant one. It is designed to be safe. You do get more active electronic ones I Looked at one of these recently. this is a computerized one.

It's ridiculous, but this one does the continuity test as well. That's a bit of a downside because even if you touch it to what what's not a live wire, it can sometimes light up and give a misleading, uh, indication that you're working with live electricity. But on the other hand, you can use this and you can just hold it in your electrical connections and it will glow to indicate that there are live electrical connections in the vicinity. Which is quite useful.

It means you don't have to cut into wires. However, this video is strictly about the neon one under my new reinvented LED replacement with no batteries. So let me show you the schematic of this first of what I've been thinking. So I shall zoom in this I shall Zoom down and focus down onto this and I'll show you the schematic and then we'll do the test and I'll stuff and deliver electrical connection and stick my finger over the end of it.

So the classic neon screwdriver that's this one has the neon indicator lamp and the one Meg Ohm resistor. The GP Chinese ones use a really inadequate one Meg Ohm resistor The proper ones like this one. Well, I'll show you the inside have a proper really high separation resistor for safety reasons. My Approach is again to use.

Well, this is the ideal circuit. It's a string of green LEDs and inverse polarity. and the idea of having inverse polarity is that uh, one when it's lit will protect, which everyone already is. One of these will light, but the other one when it's lit will shunt the voltage down to level.

It won't exceed the p-conversible which of the other LED And it means that technically speaking of little circuit board with a row of resistors along it and then LEDs on either side just matched match or alternate pairs. So you've got say three dots of leg down one side and three dots down the other. However, the way I've implemented it at the moment is purely for Simplicity using LED tape. a strip of LED tape stuck to another bit of LED tape in there with the polarity reversed from one side to the other.

so that I've got an arrangement like this and a classic a higher power one Mega Ohm resistor just because the higher power ones tend to have a higher voltage rating, but I'd still prefer to have the resistors long like that. So let me show you what's inside the Neon and the classic neon one. So inside the classic neon version, this is glued on. It's not just pressed or screwed in it, it's physically glued.

It actually broke when I was taking apart, But inside is a little plastic tube with a neon indicator in it. The need indicator has two wires coming at the bottom, but one has been taken up to other end and twisted round of the PIP and the other end is poked down through that cropped and then folded over so that when you put it into the screwdriver, it touches against the end of the tip. Here, just against that wire that's bent round the side, there is the super duper highly rated one Mega Ohm resistor stuffed into a spring which doesn't really Inspire Much confidence does it and you can see the carbon film on it and this sort of like the sort of laser cut or whatever around it and that provides a separation and also limits the maximum current and it. The other end of this spring literally goes into that little plastic cup and it touches because this wire is wrapped around here.

Um, wherever the spring is, it will basically touch that wire and push down against and that makes the electrical connection. Here is my variation. It's different. It is the double-sided hair piece of LED tape with three green LEDs Ignore these resistors.

they're just the one that was in there because it's 12 volt tape. I Have to say that I chose green because the green is the most efficient color. It's the it's the highest brightness for just a few microamps. it's the most sensitive of all the colors.

Having said that, even a good efficiency red LED will light and there's the one Mega resistor. I've got it in heat shrink sleeving for electrical separation and this resistor basically pop out then folding around so it touches the end electrode and then this spring just stuffed in the end, making the connection up to the studer or end because that was one of these screwdrivers. but I stripped the bits out and just put my own sucker chin right? Okay, now I'm going to set up the test and you can tell me which you think is best. So one moment, please begin the test with our favorite little Chinese tester.

So for this test, I'm going to stuff the Neon driver into this live connection and I'm going to stick this other one into this live connection over here. So I'll turn that on and I shall uh turn the light off so you can see this because I doubt you can actually see anything just out of interest. Can you see the uh can you see the LEDs glowing in that not really super bright lid? or you can see them gluing. Okay, that's all right.

You can also see them flickering the camera. Now to make this more interesting to get extra brightness, this is so darn. It's off the Soldier arm, but I'm going to use it as a grounded surface. Well, that's dangerous for uh, just to represent a summon in a different environment just to show you the difference intensity between standing on an insulated ladder with a neon driver and being in a more grounded environment.

So what I'm going to do now is I'm going to turn the light off and I'm going to take the exposure off and this should give her a result. We'll get a nice bright display now. So here is the neon driver and if I touch it, you can see it's not that bright. See the little dot inside, but watch the difference between me touching that and holding a grounded object touching it.

see how much brighter it is. significantly brighter. right? Here is my little improvised LED test which I'll stuff in here and when I touch the end of that, look how bright that is. a standard.

but again, if I touch something grounded, it's really bright. very visibly bright. But you can't rely on being grounded well all the time. So for reference here is well: I can't actually show you I can only show you one lit at a time with a ambient ground because uh, the LEDs clamp the voltage to the point I can't that? the noon won't light.

But if I touch the ground again I'm light, you can see which is brighter. Now the green is massively brighter than the neon. Um, so that makes me wonder. You know, Is there a future for these little test drivers just with a little circuit board with noons in it? not Neons LEDs in it? I should stuff that in there while avoiding going anywhere near near this grounded Soldier hand here.

but there we go. Uh, interesting, right? Watch your eyes, the light is coming back. So there we have it with the efficiency of modern LEDs with the sensitivity of them. Could these be the new future? Uh.

neon driver because it's kind of easy to make in a circuit board? Um, it depends the availability and means I Don't see names being discontinued for a long time and that manufacturers are already set up for mass production of these. but it does show you that there is potential for using LEDs directly for measuring the current because it literally only takes microamps to make the green LEDs glow and you do have the opt you could use white LEDs but they wouldn't be a sensitive. but uh, having said that, they're probably still probably going to Glow brighter than uh the Neon glues. and also, you could use a little aircon array with a large Matrix of the LEDs in series inside, even the alternating Uh polarity inside the cob.

I Really just to make a little dedicated Uh test indicator that just needs the external resistor, but that is it. I Would say that experiment was a success I Wonder if they'll ever manufacture them? It would be interesting to see if they did. Very interesting indeed.