This is actually a fairly retro device as reflected in the circuitry. Its original purpose was to test neon signs in situ to find faulty tubes. In a traditional neon sign there can be several sections of tubing in series on a transformer, and if one loses vacuum internally it effectively goes open circuit.
This unit is basically a high frequency and high voltage transmitter. When you touch the antenna to the side or end of a tube it will cause it to glow if it is still operational.
They were also sold in electrical retailers for testing fluorescent lamps, but weren't really suited to that task as they do not show the state of the electrodes, and only give an indication if the tube has a seal failure, which is rare.
The circuitry is interesting though, as it has strong similarities to a device called a jammer that was used on some early electronic equipment. By inducing voltage in circuitry or wiring remotely it can cause unexpected results, and in the past similar devices were used to defraud petrol pumps and gaming equipment by interfering with their operation.
Modern cash equipment has extra protection to detect things like this to allow them to shut down and trigger an alarm or in earlier equipment just force a reset.
An interesting recent example of the electrical interference was when a sign installer was driving his truck to a job and his helper was playing with the device. The helper touched the antenna to the truck door and the engine management system cut out forcing the driver to make an unplanned stop on a layby. When they turned the ignition off and on again it resumed normal operation.
These devices have other uses, but their primary use is in the neon sign industry.
Be aware that these units can damage adjacent electronics without contact. Use with care.
Here's a typical search link:-
https://www.ebay.com/sch/i.html?_from=R40&_nkw=neon+tube+tester&_sacat=0&_sop=15
Target price is less than $20 shipped.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
This unit is basically a high frequency and high voltage transmitter. When you touch the antenna to the side or end of a tube it will cause it to glow if it is still operational.
They were also sold in electrical retailers for testing fluorescent lamps, but weren't really suited to that task as they do not show the state of the electrodes, and only give an indication if the tube has a seal failure, which is rare.
The circuitry is interesting though, as it has strong similarities to a device called a jammer that was used on some early electronic equipment. By inducing voltage in circuitry or wiring remotely it can cause unexpected results, and in the past similar devices were used to defraud petrol pumps and gaming equipment by interfering with their operation.
Modern cash equipment has extra protection to detect things like this to allow them to shut down and trigger an alarm or in earlier equipment just force a reset.
An interesting recent example of the electrical interference was when a sign installer was driving his truck to a job and his helper was playing with the device. The helper touched the antenna to the truck door and the engine management system cut out forcing the driver to make an unplanned stop on a layby. When they turned the ignition off and on again it resumed normal operation.
These devices have other uses, but their primary use is in the neon sign industry.
Be aware that these units can damage adjacent electronics without contact. Use with care.
Here's a typical search link:-
https://www.ebay.com/sch/i.html?_from=R40&_nkw=neon+tube+tester&_sacat=0&_sop=15
Target price is less than $20 shipped.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
A kind of Tesla coil then !!!
I did not know that you could get neon bulbs in blue or green… Though I suppose that they're actually filled with some other gas and not neon. I have on hand here some "inverter transformers" pulled from scrapping flatscreen TVs, which I would assume were used to drive the flourescent backlights for the screen. I was wondering how one might drive one of those, now I know. 🙂 Is that transistor driving the transformer the TO-220 device I get a glimpse of briefly at one point late in the video? I wonder what characteristics I would need to select a transistor for that use?
Mine's just arrived. It ….. rattles! Sounds big enough to be the coil. I might just break it open and add a sponge sticker. I've got a couple of micro-plasma balls that burned out, hm….. I wonder if it'll drive them properly?
2 years back! I missed this one. Clive, when you said capacitive coupling is used through the batteries as the return from the HV antenna… (I don't know much about antennas and things) I read elsewhere that the "right" frequency of electric past a non-grounded wire (antenna) in a circuit "leaks" the electric out into the air due to radio emission… so would some of the HV coming from the antenna be from radio emissions? Not needing a "return" path?
The 555 timer is one of the wonders of the analogue electronic world.
I still use them – I am that old!
Reminds me of the radio shack days when i accidentally keyed up a ham hand held radio (5W i think?) and it reset the terminal i was using. Green screen glory and all. haha.
I don't quite get the need for the multivibrator/flip-flop circuit AND the 555 chip. The multivibrator could drive the output transistor without the 555 chip. OR, the 555 can oscillate and drive the output without the multivibrator circuit. Why have both?
Yeah, no thanks, I'll just turn on my portable tesla coil and every neon in 80cm radius will turn on 😂
Real glass Neon > led fake (neon) too bad the industry is going to the fake crap. I love the look of a clear tube with a glowing gas.
Good ole triple nickel, a lovable workhorse chip for everything.
Can i us this to jam ruski uavs?
On the farm here in North Devon we have both North Cornwall's main power lines run over, you just have to stand under them with a strip light or early energy saver bulb to test them, Mind you I would not recommend it on a damp day!
Like a portable tesla coil 😎
Ah, finally! A pure analog circuit…
Now you're speaking my language.
I miss the days of analysing and repairing analog electronics.
It's maybe why I love creating, playing around with, and repairing Hi-Fi power amplifiers of both vacuum tubes and transistors today still. 🤷🏻