The current pandemic has caused some very retro technology to become popular again, but with a new twist. In this case it's a really clever little power supply for driving a low voltage gas discharge tube with current limited AC from a 12V DC supply.
The load is a classic GTL3-style UVC lamp that I featured in another video. It's very odd in that it uses a filament with emissive coating at each end to allow a mercury vapour discharge at low power and voltage. Literally just 10V RMS. (RMS means Root Mean Square and means an average.)
Traditionally these lamps were used in older style laundry equipment for air path sanitation, and usually used a 24V AC transformer with a beefy resistor in series to limit the current. There are sellers on eBay selling kits with just a PHAT capacitor in series, which may potentially cause sputtering (electrode damage) in the lamp. It's notable that people have been buying these lamps and screwing them straight into lamp holders with fuse popping results. They must have a current limited supply.
This circuit seems to be custom made specifically for this one task. I've never seen a low voltage configuration like this before.
If buying one of the lamps to play with, keep in mind that they do emit harmful UVC light that will cause eye and skin damage like a welding arc. There are two types - plain UVC and the more useful UVC and ozone. What actually turns up tends to be totally random.
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.
The load is a classic GTL3-style UVC lamp that I featured in another video. It's very odd in that it uses a filament with emissive coating at each end to allow a mercury vapour discharge at low power and voltage. Literally just 10V RMS. (RMS means Root Mean Square and means an average.)
Traditionally these lamps were used in older style laundry equipment for air path sanitation, and usually used a 24V AC transformer with a beefy resistor in series to limit the current. There are sellers on eBay selling kits with just a PHAT capacitor in series, which may potentially cause sputtering (electrode damage) in the lamp. It's notable that people have been buying these lamps and screwing them straight into lamp holders with fuse popping results. They must have a current limited supply.
This circuit seems to be custom made specifically for this one task. I've never seen a low voltage configuration like this before.
If buying one of the lamps to play with, keep in mind that they do emit harmful UVC light that will cause eye and skin damage like a welding arc. There are two types - plain UVC and the more useful UVC and ozone. What actually turns up tends to be totally random.
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.
I'm reminded of the time when I was a kid and I encountered a scrapped washing machine. Among other things I pulled a "germicidal lamp" (it said so right on it) out of it, which was wired with a "ballast" consisting of basically a series inductor about the size of a small audio transformer. And yes, it did work when I applied some power…
Low voltage or extra low voltage?
Great video! Do you happen to have the transformer ratings or the part number at hand?
Hi.Could I use a mains filiment lamp in series across a power supply fuse holder to let me test a faulty psu that keeps popping fuses????? Thanks
What make is that portable oscilloscope, please?
Just a bit more circuit theory absorbed with every nutritious video Thanks Clive
That circuit has a huge potential for self-destruction if run without a load. There are no resistors to limit the current flowing through the bases of the transistors and no reverse polarity protection as well.
You could cover the lamp with a clear drinking glass, which would block the UVC light.
👍
If you're using that lamp in a future video stick it under a glass cup. Glass is very effective at blocking UV
How do you like that little oscilloscope? I was thinking of getting one like that, but I don't know how useful it would be.
can we fed the lamp with CFL ballast?
what harm to humans from running that lamp like you did for more than a few seconds? i dont know what the danger is please explain thanks
Sorry Big Clive, I was drunk last night but I do enjoy the way you talk about elekyraniks