Cute vintage resistor ballasted fluorescent tube

I can remember buying this from one of the big UK component suppliers, because i was intrigued by a fluorescent tube being run directly from the mains supply with nothing more than three resistors.

The main resistor is for limiting current, and the other two are for limiting current to strike electrodes at each end of the tube.

It's reminiscent of the classic mercury vapour lamp with internal strike resistor.

I'm actually getting deja-vu of another video I made ages ago with a similar tube in a night light. I finally found the video, and it uses a combination of resistor and capacitor as the ballast, but the same four electrode style of tube.

This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.

#ElectronicsCreators

[TheToastPeople]

That has to be the cutest fluorescent lamp i ever saw!

[TheRealWindlePoons]

"It feels like I'm about to power something up which could be destroyed instantly." Honest and fearless as ever, thanks, Clive.

Reminds me of my days designing and de-bugging control systems for one-off machines. One of my favourite conversations from a fearless site installation engineer went:
"What happened, Eric?"
"It went bang, it smelt funny and this bit fell out of the bottom."
The "bit" was the end of a large electrolytic capacitor from an inverter drive which got 440V up it's input instead of 250V when the customer didn't bother connecting a neutral to the panel...

[carstensteinert]

Ah, the memories!😅 As a child i was fascinated by gas-discharge-lamps. There where also small Nightlights from a manufacturer called 'Lampi', wich contained a 4 Watt fluorescent Tube. The ballast was formed by a foil-capacitor. Those lamps only contained 5 components and the tube in total. They were prone to quickly become black at their ends because of the way they were driven. A tube like the one you showed us here was long time the backlight for my parents home-stereo, after the original bulbs burned out. Used an adjustable 12V-driver to power it.😊

[johnrehwinkel]

One thing I like to do, to visualize interesting electrode structures like that, is point a laser pointer at the phosphor on one side, which basically creates a point source of light that projects a shadow of the electrodes onto the phosphor on the other side.

[mikeselectricstuff]

I have one of those somewhere - no idea why I have it!

[Alan_AB]

I love looking at the old stuff. That's the stuff I was learning on when I served my apprenticeship back in the 1970's.

[gordonfreeman]

Clive - we love seeing stuff like this. I imagine you have quite a vast collection of vintage electronics, especially lights like this. We'd love to see more videos like this!

[robsmith]

Nothing quite so grand as when Clive goes digging through his old draws

[timothyjones]

That's truly wonderful. I actually have a 4 ' fluorescent fitting that has a resistive ballast, obviously with a conventional starter though. Historical lighting technology has always been interesting.

[DelticEngine]

Very nice video, Clive. I admit I thought I knew what this was at first, and how it worked. But then came the circuit diagram and description and I realised I was incorrect and that this lamp is actually much cleverer than it first appears. In a nutshell it's a couple of neon indicator lamps, one in each end of a short fluorescent tube and with appropriate current limiting resistors, to make what is basically a giant tubular neon indicator. A pair of neons within a neon, kind of thing. I like the thinking behind this and the simplicity of it. Very nice.

[gregorythomas]

A tiny little fluorescent lamp...too cute :)

[JendaLinda]

There's always something magical about the glowing plasma inside discharge lamps. Happy new year!

[nrdesign]

Fascinating item. Gotta get 28 in total and make it a full 7-segment clock!
Also intriguing that the datasheet has some german words in it

[markae]

Even though they are obsolete I do enjoy the fluorescent tube.

[herosstratos]

Back in the day, operators used to attach a small fluorescent tube to HF-antennas to monitor the transmission power.

[KeritechElectronics]

All photonic, no induction! Interesting little fluorescent lamp - I'd never expect it to run off 240V with 10K in series and 220K for each heater.

[lahtinenk]

I have that kind of lamp as decorating light in a ceramic lighthouse (Cape Hatteras) and it has lasted a long time. It is also very suitable for it. So it was very nice to watch your exploration.

[Rosscoff]

Reminds me that when my parents got a (then) fancy fluorescent light fitting in their new kitchen in 1959, there was also an incandescent ceiling lamp that came on with it as some sort of ballast.

[bluerizlagirl]

During the 1980s, someone was importing car inspection lamps that used a miniature fluorescent tube, with a resistive mains lead as the ballast. If you coiled or bunched the power cable up, all the heat it generated was concentrated in one place. If you damaged the lead and shortened it too much, the now-excessive current could blow the tube.

[asciimation]

Gas tube stuff is so cool. When I was a teen, lets just say in the 90s, my aim was to find/play with three different 'tubes' - a He-Ne laser tube, a Geiger-Müller tube and an Infra red image intensifier tube. I managed to find and make work all three in the end. I still have them as and they all still work as far as I know. I won the image converter I think from Oatley Electronics in Australia with a project that used a CD as a diffraction grating at an angle to measure the wavelength of a He-Ne laser tube. I think, that project might have won me another He-Ne laser which I also still have. Was a long time ago :)