Reinventing the neon test screwdriver
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- เผยแพร่เมื่อ 13 ก.ค. 2024
- The classic neon test screwdriver has been around for a long time. It relies on the sensitivity of a small neon indicator bulb in series with a safety resistor to give a slight glow when touched to live electrical connections by finding a return current path through the user.
It has a few weaknesses. It's very dim to start with, but even dimmer when the user is well insulated from ground, some have inadequate safety resistors, and it's a very vague test that is not always reliable.
With the sensitivity of modern LEDs I thought it might be worth testing to see if they could be substituted in place of the original neon indicator to provide a brighter indication.
Note that this experiment involves direct electrical contact with mains referenced circuitry. It is imperative that the resistor is chosen with safety in mind, and that the internal wiring can't short out the safety resistor accidentally.
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This also keeps the channel independent of TH-cam's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators - วิทยาศาสตร์และเทคโนโลยี
I like the LED version and brightness is definitely an advantage here, but neon being the simplest, is probably more reliable.
you can just replace neon with led rod from incandescent lamp imitation. as drop in replacement with the same simplicity
But leds will break as short circuit and a neon bulb will just not light up at all while being highnimoedance. So it‘s much safer with the neon lamps I suggest 🤔
But the neon screwdriver is contact only. So you can't use it to detect the electric field emanating from a live line behind the wall.
My concern with the old-school neon version is the glass. If you drop your screwdriver how likely is it to break?
@@eDoc2020 From experience the plastic handle tends to break first.
Also a good demonstration of why we have "one hand in a pocket rule" if you must work with live voltage.
I did not know this and did some googling -fascinating while a simple concept we need a Big Clive video breakdown.
I assume this is the same as what I was taught. One hand gripping my belt behind my back.
Should any current be induced in the body that hand would hopefully clench up and be prevented from closing the circuit across the heart.
Left hand in the pocket was allegedly begun by Nikola Tesla (I don’t buy it myself) because even while he was working, it was known that current passing through the heart could stop it, and avoiding current passing into the left hand lessened the possibility of stopping your heart.
Shake hands with danger.
There is no such rule! It's advice! And it's a pretty dangerous one if you are on ladders, fault finding some lights on a ceiling, as you can lose your balance and fall off with one hand in your pocket! Pretty daft idea!
Great work Clive. Thanks for the time an effort. Can see that a fair amount of time was put into it.
and, not an.
@@stevenA44 Yup another grammar Nazi detected.
And stop giving yourself a thumbs up freaky boy. 😎
Clive, don't forget that a neon has a 50v strike voltage. So with a neon, it'll only light when above 50v.
With 3 leds, it'll light up at any voltage above around 10v. Yiu need a zener in there... 😀
One of the only applications I can see for those insanely bright blue LED's.
In re green LEDs being the most efficient: it's also the colour to which our eyes are most sensitive. I did an SYS project on this and having got the wrong answer during my interview I will never, never forget that the wavelength which appears brightest to human eyes is 555nm.
Green LEDs are actually among the least efficient in terms of actual light output. The high brightness per watt is purely down to our eye's sensitivity.
From memory, blue LEDs are the most efficient by far (largely driven by the huge demand for efficient white LEDs).
@@JMMC1005 I think some yellow LEDs are less efficient than green. Im not sure about IR and UV LEDs.
@@mernokallat645 That's possible. I know that the power IR LEDs I've used also got damn hot, so I wouldn't be surprised if they were pretty bad.
Interesting. I'd like to see some measurements for both versions. Actual current for a start, if you've got a meter sensitive enough, both grounded and non-grounded. Also voltage drop across the screwdriver and across your body when grounded. I've a feeling the neon drops a higher voltage than the LEDs, so would be considered "safer".
Using ordinary 3 or 5mm LEDs instead of the tape might give better all round vision, although the neon ones tend to have a little "lens" over them so you can see the tiny glow better.
As a rule, I've always found the neon hard to see unless you are working in a rather dark area. Your LED version is very easy to see.
Very interesting 🧐 I like the LED version better than the Neon indicator.
But it's too dangerous. Would you not consider converting it to a logic tester for your safety and the safety of others if you find it so attractive?
@factorylad5071 lots of people say this but has anyone actually died using them
@@factorylad5071 no, theyre not dangerous if designed and used properly,
@@andygozzo72 yep as Clive said, the real danger is the inadequate isolation of cheap designs.
Your implementation with the LED's is by far superior - and looks great as well. I'd happily buy and use one.
Very informative video, doubt I’d touch the end on live connection, I will stick to vde 1000v compliant test gear, but respect to Clive, and respect the beard 👍🏻
I just like how such things can glow when plugged in extension cord that has switch in off position.
Feels like magic.
Only néon and leds.
It means your switch is single pole. It's illegal in France, all our cord switches must be bipolar.
Yes, the problem with a series string of diodes is that they don't share reverse voltage equally or in any specified way since it depends on the leakage current vs reverse voltage curve. Your third option with three independent groups of LEDs looks more attractive.
I think the Neon lamps are safer and last forever in such application.
The fact that diodes fail short is disconcerting. Neon lamps have two plates separated by gas, not much can go wrong there.
neon lamps die too the glass can break. or something can disconnect. led will also last forever
Even if the LEDs fail short it would still be safe. That's why it's better to use the version with several resistors in series to spread the voltage and keep it safe even if a resistor is shorted.
I was thinking the same thing. Some circuits I have seen, which take a voltage reference from the mains, do so with a whole stack of resistors in series for safety.
The classic neon screwdriver uses just one resistor, and my thinking was that neon bulbs added the additional protection.
Nice video there and interesting as well. I prefer the definite brightness of the LEDs as I have found on occasions it is difficult to tell if tge neon has lit up or if it is a reflection off something else. There will be the traditionalists out there that will prefer neon over anything as that is what they have used for the last 20 years but they fail to remember that before these testers we used apprentices to test for live wires, if they made a mig of tea afterwards it was safe to work, if you needed the plasterer to repair a human shaped hole in the wall it was still live 🤣
Obviously the last part is a joke but the traditionalists will still favour neon 👍
Clever idea Clive - clearly the green LEDs appear much brighter.
The green light usually indicate that something is acceptable. In this case it can indicate that it is acceptable to touch the wire which is currently tested. Some other color could be better in this application.
Our eyes are very much more sensitive to green light. If one were to observe a green and a red laser beam of the absolute same power levels, the green beam would look MUCH brighter to our eyes, even though the beams are both the same in terms of output.
The little voltage tester was dim
Invisible to see on a whim
Clive took it apart
designed it on spot
This video gave me a grin
Here's a true neon screwdriver tale: I had a close call being up on a ladder many decades ago in a friend's factory in London checking to see if a 440V panel is dead or not before ripping it all out and redoing the connections.
On that day I didn't have a neon tester so instead I was using a multi-range tester, holding the black and red probes one in each hand while leaning forward to the electrics to stay on ladder. I carefully dabbed the probes to various places but didn't get any voltage reading at all, it didn't make sense and it completely messed up everything I had planned out. All I got was the reading briefly just tiny jump slightly from zero when I made the probes contact. I wanted to confirm the voltage was there first then shut off that circuit only.
So I just came back down from the ladder, very puzzled, I then packed it in until the next day. Next day I came back in to repeat and then I noticed.... the tester was switched to DC VOLTS instead of AC. DOH! I was THAT close to a major calamity but my '6th sense' + logic had saved me.
If I had instead a Neon Screwdriver in one hand then I wouldn't had needed to have a 6th sense + logic to protect me. = much safer.
What if the ladder increased your resistance to ground and the neon wouldn't have worked too?
@@jor7137 Very good point..... if the metal ladder I was up on had been instead made of insulating plastic, but a wooden ladder that's more feasable. I'd still be puzzled all the same why a neon hadn't lit up for me first before I'm ready to cut the power, then I wouldn't had proceded any further by default.
I just now remembered all those decades ago when I used a wooden ladder: I would leave a reel of insulated cable down on the ground and then carried up the loose end with me still insulated.
Then came out in the 80s the non-contact LED 'volt-stick'. I guess if I'd used that the combined wood together with proximity acts like an almost short-circuit impedance?
This all just neatly proves:
*the most sinister and deceiving failure of a safety feature - is the one which is believed to be reliable*
@@jor7137 By the way had you seen that YT video of the HV (500 kV?) line worker on a platform attached to a hovering helicopter, clipping on dampers one at a time to each live phase wire. There was a huge long spark in front of him as he approached. He definitely wouldn't had needed a neon tester!!
@@jor7137A neon tester would still work even if the ladder was insulated . They work even if you are wearing electricians safety shoes.
If the path to ground is blocked by an insulator such as a wooden ladder , neon testers will use the capacitance of your body to function. Any insulation such as rubber soles or wooden ladders, become the dielectric of a big capacitor where your body acts as one plate and the Earth as the other.
Try it , you can jump in the air while one of these things is glowing , and as long as it stays connected to the live, it will continue to glow.
@@graememorris7820 Good points. I had them give false positive before. Not sure about false negatives
Brilliant update and thanks for answering my previous question. Might look at making one.
It's a nice idea. Much though I love neon testers, and believe that alongside their great value as a cheap and simple diagnostic tool, they are invaluable as safety equipment. I have heard tell of - and experienced personally, countless instances where their ease of deployment has given timely warning of an unexpected live. Some people bang on about them being electrocution hazzards, and sure, this may well be possible if one plays submarines with them before use, but I haven't heard of one electrocution occurring via these devices , yet I've heard as I say, of countless instances where danger was averted due to them. Their greatest drawback , is their dimness , which makes them unsuitable for use in bright daylight. Making such a tool brighter as you have done, has to be a good idea.
Another drawback they (neon testers) have , is that they are limited in the voltage they can safely handle. For most home DIY ers this is not a problem, as most of us will only be probing 240VAC. But they can cause electric shock if inadvertently used on voltages higher than their rating.
As an edit. I'd like to add that although as I said, electric shock could occur if neon testers are used to check voltages higher than their rating. I mean shock - electrocution even so would be difficult.
If we consider the ballast resistor in the tester to be 1Meg ohm, than to pass a current of 7mA , which the smallest current known to be fatal (across the heart ) , 7000 volts would be necessary.
The thing to remember is that even with the good old Martindale tester you were still instructed to test it on a known live source before using it! Worth remembering if it is hardly ever used and gets damp/corroded in the bottom of an old tool bag and goes o/c! Common sense and a little electrical knowledge can go a long way!
Used to love proper neon screwdrivers, they're great for detecting the presence of high frequency AC, you just hold the body of it near to the source and if it's energised the neon glows.
Dead handy for working on old CRT tellies and radio gear because it takes a good whack of radiated energy to light it up..
There used to be a craze of added neon light on the end of transmitting antenna. Lights up and flickers with your voice as you spoke.
The neon bulb has high enough resistance to prevent a lethal shock even if the megohm resistor fails short circuit. The neon also has other uses checking for microwave leakage or standing waves on an antenna circuit. LED’s offer no protection, hence your suggestion of using three resistors in series. Fifty years of using neon screwdrivers as a quick sanity check gives me a degree of faith in these simple devices that I don’t have with the all singing and dancing high tech solutions today. Yes, you do need experience of how to use them properly and appreciate that no light never means a guarantee of no voltage!
The impedance of a neon lamp once struck is quite low. Certainly low enough to carry enough current to be dangerous, tens of milliamps if not more just for a small indicator lamp. It would be highly dangerous to rely on the neon to protect you if the current limiting resistor failed short.
Brilliant explanation Clive really enjoyed your version too 😊
Brilliant research work here BC well worth the time to make one of these 2023 versions!
I like the LED version. Well done Big CLive. 🍻😉
That's the finest universal continuity tester (FUCT) or possibly the finest universal continuity-tester known..............
FWIW: When I was a kid I did just a bit of 'messing around' with a couple of small neon bulbs. {This was back in the 1970s.}
I had {and think I still have} a small hand-cranked surplus magneto generator I would hook to one bulb to light it.
I also THINK at one time I had one bulb attached to a wire or small antenna {or SOMETHING} outside my bedroom window that would illuminate when a thunderstorm was nearby. Living in Saint Petersburg, Florida {USA}, afternoon summertime thunderstorms were a fairly common occurrence...😊
They will sell very well as the "Clive Probe" 😁
The neon has a much higher threshold which could be useful. To duplicate the effect a couple of back to back zeners in the 68V range in series could be added.
Don`t need zeners back to back, look up Tranzorb diodes !
@@pjeaton58 Transzorbs are much better for transients and less accuracy on the point at which they start to conduct. In this application I'd stick with zener diodes.
I would be surprised to learn these did not already exsist on the market
Thanks,great idea.
LED brightness is a plus!
Beauty!👍 Id buy one.
Great idea! patent it quick 😮
Haven't used one of those things in 30yrs, didn't know they were still made. I have one and think it's neon, will try to find it.. Thanks Clive👍
I still use a neon or a volt stick when pulling a switch or socket off the wall in an unknown house, it’s amazing what you find, and I don’t like finding current with my skin. ( Why the hell is it always the tender skin on the inside of my elbow !?)
Awesome Video big clive
The LED version is probably better by all accounts, but I prefer the neon one just because it’s neon and I prefer the aesthetic. (I own a Nixie clock for that reason too).
I want one, nice work
LED is bright & easy to see. But neon is indestructible! Won't fail ! And Even if a high voltage is applied it won't electrocute you! Raj (Chennai) India.
Nice work.
Very cool demonstration...You ROCK! Big Clive...Cheers! DVD:)
I was taught to keep a hand behind my back working on TVs as a lad. Nobody mentioned it during my later education, even though most professors had long white beards. I still automatically do it if I'm poking near dodgy voltages.
I prefer my 1980s neon tester it just works from any angle.
I was waiting for this video. 😊
Smart idea to repurpose LED tape rather than make a PC board up - GR8 'out of the box' thinking!
Great video, thanks Clive!
If I might add: I think the neon being a tad safer as their failure mode is generally open cct whereas LEDs is a more 'direct' connection.
Either way its 'only' mains voltage.....(he said while schmoke billows from his brightly glowing ears and now badly burnt nostrils, hair on fire) 😂
Also: money shouts louder than safety: neon wins due to being the very cheapest implementation of this design!
cool idea 💡
I really like the LED version much better than the Neon just due to the fact that they are way brighter...especially when on a grounded source...easier to read in a bright environment.
Have you thought about making a small batch of these tester replacement boards...maybe even recording the process too?
I have been missing your longer videos...I even rewatch several of them over & over again :)
Very good led conversion you made there Clive. The LED's are a lot brighter. I thought that most LED strips are power hungry. A high efficiency LED can glow at currents well below 1 mA.
Awesome!
I prefer the Neon based one because it's a classic.
What i liked about the NEON version was you culd wave it near the flyback transformer of a tv set to check for EHT.
Although it could be seen with green only, having different colors for each polarity would quickly tell you the direction of flow or if it is AC vs DC current.
Countdown to seeing your version reproduced showing up on ebay en mass
Bet we'll see it now. Now that you've done the work.
Interesting. Mine has a different design. It contains spring which is connected to the red cap and is pushing to a glass fuse where the fusible wire was replaced with a neon and a resistor inside.
But sadly the transparent plastic cracked and the red cap fell off and when I glued it back the glue covered the fuse with a white film overtime and slowly terminated the connection between the spring and the "fuse" so the neon won't turn on anymore.
I hope they will make these simple test screwdrivers with LEDs instead. And it looks nice with the green ones. But I like the neon variants too.
I'm sure you must have used the older ones that had a screw on end cap, which was always handy so you could tip the water out of them after picking it up out of the puddle of dirty water you'd just dropped it in, that would have been shortly before your teeth were rattling around in your head 😮
If I recall when I was working on human interface with mains voltage we had to allow for any direct path where humans could touch live would require a limiting resistance. We had to assume a resistors could become s/c or o/c.
Safety resistors were too expensive, and not all approval bodies would accept them other than the ww type.
So in order to say create a 330k resistor, we would need to use 4 resistors (a parallel pair of 330k and then another 330k parallel pair in series). The ww fusible resistors only went up to about 1k, and you needed to limit current to a few uA. This meant you had to use around 1M for a 253V AC rms (240 + 5%).
Fun fact neons need a few photons to cause the gas to initiate the flow of current between the electrodes, even after the striking voltage has been reached. If you wanted to use a neon in a dark /sealed environment (relaxation oscillator or as a voltage regulator), you needed a small light source near it or to cover the inside of the neon bulb with a bit of phosphorus that will glow due to electron radiation from one of the charged electrodes.
I built a tester after getting new green LEDs, It works great, even in a lighted area. Being that I am only using this on 120 vac I reduced the current limiting resistor to 220k. Tested it with one finger on the tester and an adjacent finger directly on a ground, absolutely no sensation of shock. It stays below the 400uA threshold for sensation
Endlessly fascinating 👍
Awasome 😊 sir, very good
Before the video was half done, manufactories in the Mystic East were already churning out your tester, Clive!
I really like the green leds one 👍 Great video like always. BR, Per (DK)
I must defend the the much maligned neon screwdriiver and your improved LED version. I was brought up on this device when Avos other testers were too bulky to carry on a push bike and providing you understood the limitations as you must with all. test gear. I was once sent to investigate why shocks were being given from a cold water tap, the neon tester lit when placed on the tap! Of course the tap was not alive but the floor was, reaching in through the doorway and digging the neon screwdriver into the wooden floor there it was. The floor was soaked in moisture and chemicals and was conducting from a faulty heater next door
I like the neon version better for 2 reasons: Its classic and worked for decades and plasma give more feeling than a solid state LED.
My neon tester still works great for 60 + years.
You have to have trust in your equipment.
Never knew the black part was a 1 meg resistor.
Interesting! 👍🏻😀🇬🇧
When you find yourself sitting on the floor 5 yards away from the panel you were working on, with smoke coming off your beard....it was definitely live.
Clearly AC and not DC then - if it was the latter you’d be bouncing around stuck to it like a pin-ball.
3:25 bigclive trying to avoid saying "shaft" in a delicious scottish accent 😂
There’s nothing like a nice Neon bulb. Nothing even comes close to a nice neon glow.
Reminds me of the "significant hit" I had from a (probably Chinese) VERY cheap Neon tester decades ago! Made a very basic version of this using two red LEDs in inverse parallel, and a 500k resistor. Bright enough to almost read a book by , and I wonder where that device is now -= somewhere in the garage I suppose 😀
500k will deliver letal current when used on triphasé 400v. Also you probably used a 250V resistor which will arc on the 310v part on the top of the wave, which can kill you in 0.2 s.
Big improvement over the neon version IMO. Expecting Chinese copies in 3… 2…
Big Clive
The man who contributed to the demise of real neon bulbs... 😢
I doubt they are going to disappear any time soon.
Don't know. Compared to an LED they're pretty complicated and expensive to produce. I already have a glue gun that has an LED + resistor where there used to be a neon bullb.
Perfect timing, Clive, good sir! I'm currently having a sort of online debate/car crash with internet experts who claim that nobody uses neon test screwdrivers because they cause the Coming of the Dark Lord, or something.
In the old days, the neon bulbs are brighter and lighted bulb can be seen easily.
Nowadays the neon bulbs are poor illuminated that may be seen as no high voltage and caused electrical shock.
For safety, I use clamp meter with NCV for AC high voltage non touching testing.
It may be easier to do an LED version that fitted in the larger version of those electrical test screwdrivers. If a pair of RGB LEDs was used, they could be configured in inverse-parallel with a resistor for each pair. The resistances could be chosen to give a particular colour, possibly including one approximating a neon.
Never thought it would be this simple to use LED's in one. It makes me wonder whether one couldn't make a nice little decorative light without a neutral connection. Super simple design and looks really nice with the slight flicker.
without a neutral, I'm guessing that if you add enough of them, you can trip the earth leakage protection
That's called the antenna effect. It's technically capacitor efect. I see it every day when leds are used with very long wires, they glow even when switched off.
@@rexsceleratorum1632 Good catch. Still would be a nice light but probably should use the neutral instead.
@@Benoit-Pierre Yeah, but that isn't done intentionally. That usually happens with cheap lights with no resistor across the led's.
@@memejeff It happens in most wall switches that include a witness (the witness may light in the wrong situation) (Legrand Mosaic, Celiane, or Plexo using LEDs like 067686 ), or alarms like Legrand 076671.
It also used to happen with LED bulbs used with halogen regulators: even switched off, leakage current could still light the lamp; recent regulators now fix this issue. You can also fix the issue on the bulb side by adding a parallel 0.1uF X2 capacitor (X2 does not means times two, but the letter hix two is the capa classification).
I'm voting Green in this experiment. Of course each component will be considered on the pennies-per-pound cost point. ( or cents-per-0.45Kg)
Love ya brother.
It would be interesting to read the current in µA. The green LEDs are acting similar to LED lamps that continue to glow dimly after the power is shut off due to leakage currents.
Good quality Green LEDs need only a few hundred microamps to look reasonably bright. It depends a lot on the quality of the LED; there are so many shysters selling LEDs with defects, especially ones with bubbles in the clear epoxy. If you buy LEDs that are not mounted on tape, there is a high probability they're factory culls.
@@acmefixer1what do you mean by mounted on tape?
@@chloehennessey6813components with leads are shipped stuck to one or two strips of tape for automated handling
@@chloehennessey6813on the reels that they come on for mass production probably.
I've experimentet quite a bit with leds and ultra low currents to recreate tritium keyfobs.
Green doesn't work that well.
White (warm white as low as 1800k 3535 leds) are by far the best. They can be seen at normal room brightness at as low as 2μA. Green takes ~10μA to be as visible. The second best are blue and ice blue leds followed by some kind of pink. Red and yellow are the worst taking >20 μA to be even visible at lower light conditions.
I'll take 2!
Call it the Big CLive Tester. I would buy one.
I love how Clive pronounces Neon ;) Was treated to hearing it 19 times - some in rapid succession! Haha
I feel like there could be functionality added to this with a couple transistors so that a green would show 12v (ac or dc), yellow could be 120v, and red could be 240v. I don’t know how to design that, but I bet Clive could.
That would be pretty cool but the idea here was to be stupidly simple.
Actually im pretty sure its not possible to get 12vdc to show up wireless like this, you need a ground wire.
@@snigwithasword1284 Yeah - I was unclear on the operating principle of the light. I didn't think it was using HUMAN FLESH as a virtual ground. Maybe it would be possible with some sort of boost converter? It's quite possible that I have no idea what I'm talking about.
In general, electrical engineers and contractor frown on neon test screwdrivers as being dangerous and unprofessional. I personally have always found them useful, provided they are used with caution and with awareness of their limitations, such as not probing excess voltages above 400 volts peak breakdown voltage, so basically limited to mains 230 volts. Though in my day it was 240/250 volts A.C..
In their heyday, the neon bulb was constructed like a fuse, with a glass tube with two end caps. The series resistor was specified to provide a good margin of flash over protection. The neon was designed to strike when the voltage between its end caps was between 60 to 90 volts, though they might start glowing at voltages as low as 42volts. They were specified to light at 100 volts.
I suppose the main weakness, was that the glow was not that bright, and depended on the user providing a good earth with their finger touching the end cap of the screw driver. In the days of valve TVs, there were some times used in the highly dangerous practice of detecting the CRT EHT field, this did not require touching the end cap.
Their greatest virtue was simplicity, not an a attribute that could be used to describe the very dubious modern alternatives, that require a stack of button cells, and contain a microprocessor circuit.
The advantage of the neon bulb over an led solution, is that it operates at a high voltage, but very low current. The little neon fuse like bulbs were once common components. My very first stroboscope was made with one of these neon bulbs mounted in a bicycle front light reflector It worked, but was not very bright.
I think you should flash test your LED version, as that is the critical parameter. I certainly prefer your version to anything containing batteries.
Not sure that such test screwdrivers have much of a future. Their reputation has been damaged by the cheap Chinese imports, that use inadequate components, that make them very unsafe to use. Professional electrical engineers want such testers banned, so they may disappear as a result of some EU directive.
Also another thing these devices are useful for: to find which conductor is the phase. Yes, in an ideal world conductors have the proper color and everything, in the real work you open a derivation box and you find all black conductors, or colors that make no sense at all. This is why in my country this device is called "cercafase" that is phase finder.
Another less common use case is to touch appliances to know if they are grounded correctly. If you touch the metal case of an appliance and the earth is not connected the neon will glow slightly. This is because the filter capacitors let some current (not enough to be felt or to trip an RCD) to ground, that is enough to illuminate the LED.
Or in general to know if a ground is good, for example if you touch with the scredriver the earth and the neon illuminates it means that that earth is not really connected to ground. That could indicate a break in the cable. Of course these are not scientific tests, but a cheap test to do to find potential problems, that then will need to be investigated with the proper testing tools.
Big Sister Robot: Why do Grandpa's eyes keep flashing on and off. And that green colour is really creepy.
Little Brother: I don't know. But it's every time he walks past an electrical socket.
I am an aging Luddite who has an entirely irrational love of neon lights!😂. Nice prototyping though.
Lovely to watch a video where somebody isn’t giving a comment about Huw E 👌
Would be interesting to plot some measurements and see how they vary with dry vs wet skin etc. If there is a reliable gap between grounded and non-grounded thresholds, could the circuit be improved by setting a couple of comparators at those levels - then you would have a logic signal you could do anything you want with (like light LEDs at full intensity :P )
You can feel the difference. Hot sweaty environment can make it a bit tingly.
The ol' "testicle pensicle" has saved many a lecky from unexpected live ones. In bright light you feel it before you see it.
240 / 415 VAC control circuits are still around.
Can't wait to see Clive on Dragons Den with this invention!
I still used the red color. From my highschool up to now and it works well. The others may be expensive
You're the only stud at the other end Clive 😂
Great tool! Maybe put a diffuser around the LEDs to make the light signal omni directional, or even a light pipe to lead it down the driver’s end to prevent it being covered by the palm🎉
Diffuser reduce the visibility. 28y of using those testers. You want a single point to see it better. If you can't see the point, you just turn the screwdriver.
I still have a couple or more of old style live wire checkers with a "glass fuse style bulb" 20mm and 32mm neon lamps and even longer capped leadless resistor (neon wasn't so demanded in semiconductor production and soviets supplied enough of it not to be greedy of used amounts).
Clive, you can get 350 volt resistors type MFR4-1M0FI from uk Farnell (code 1100042):
Through Hole Resistor, 1 Mohm, MFR, 500 mW, ± 1%, Axial Leaded, 350 V
I normally use this type for the start-up resistors in SMPSUs. Usually 2 x 47k.
Clive that was cool. I'm surprised that they would glow at that low current, let alone how bright they are.
Clive hope you get royalties when they switch over to LEDs from Neons.
We gotta get you an investor so these can be mf'd.
Again thx for sharing.
There's no point even trying to protect a design or get royalties on something like this. If it took off it would be a Chinese free for all.
@@bigclivedotcom Agreed, you'd have to beat them at their own game by finding a Chinese mfr to make & pkg these for you quickly to be first in the mkt. Sounds like a crowdfunding pjt.
Beat'm like a drum.
Neat. The only very minor nitpick I can come up with is the LEDs are only visible on one side, while the neon one can be seen from any side. Probably a very easy fix with something as easy as twisting the LED strip so an LED can be seen from just about any side.
Doesn't he have two strips of three each in inverse parallel? It's not omni like the neon but should light on two sides, not one.
The LED strip was double sided.
I would try using one or two LEDs taken out of some damaged light bulb. The high voltage kind, the one that glow at about 40V. They should be much better (brighter) than neon at a current typical for a voltage probe.
I made a small pcb with few dozens of those in series to make a very high voltage lamp and played with static electricity. Surprisingly bright. I was going to try to light it up under high voltage lines and perhups leave it there as a modern equivalent to Will-o'-the-wisp kind of thing. A small light glowing in the middle of nowhere.
Nice :D