Fun with CFL or UV light bulbs and electronic balast
In my previous article I wrote about CFL, CCFL and UV lights. And I mentioned that UV light is good in sterilization or germ killing techniques.
Here we will talk about powering those light bulbs with dc "ballasts" or better say DC power supplies or converters.
First, lets talk about kinds of CFL, CCFL and UV lights.
The most common is E26 base CFL bulb. It was used in most household and businesses.
This light normally consist of base, power supply inside and the CFL bulb itself.
To demonstrate in pictures, I opened one of those for you.
You can do it too with a few skills of careful disassembly techniques and little time on hand.
1. Find a spot to work preferably in a garage or in an open air in case if you break the glass and mercury vapors gets out.
2. Take a towel or a rug and wrap around glass part just in case if you manage to break it. Although I can tell you, in 30 or so bulbs I opened, I never broke glass on even one of them.
3. Take a screw driver and start applying gentle but stern push in the seem, which is in between the base and the top plastic (please see the picture 1). After that go around the seem and gently try to crack open the base of the bulb. Please see another picture on how this base comes slowly apart.You can see how the screw driver sometimes crack plastic while you do that. This is no big deal for as long as you won't break the glass tube.
4. Eventually the whole thing will come apart like on this picture
And you will have to gently take the glass tube wires off the PCB (electronic board).
And vuala, you have a mercury filled, fluorescent spiral tube.
Interestingly enough, I used only burned bulbs for doing my experiments. In 99% cases, those E26 bulbs burn at electronic board or one of the filaments inside the tibe is bad. But in our electronic ballasts we don't use filaments. So even not working bulb will take a second chance to glow.
Let's talk about CFL bulbs itself for a few seconds.
Normally those are drawn like this on schematics.
For those who wish to make them by yourself it is not a big deal. One days of work and you should have your own dc ballast. But those those who need them now, we have those in stock here(click).
The reason why is because they have filaments (hot, glowing elements on both ends). This is why we see 4 wires (two on each end) coming out of spiral bulb.Filament is needed to have easy time to emit electrons out of cathodes (filaments). But in reality gas could glow even without turning on heating elements. Normally it takes around 300V to start gas plasma in that mercury tube if heating element is hot. But at 600...700V electrons and ions bombard cathode with anode anyway and start plasma without heating element.
So this is used in most (99%) conventional electronic ballasts.
Those ballasts are high voltage power supplies, which has around 600...900V output. And yes, you could zap with those power supplies pretty bad or even use for cattle fences or animal guards. They are not lethal for a split second touch, but can give extremely powerful jolts. Way more powerful then even shockers because they give more current. So connect or disconnect bulbs from electronic ballast only when they are not powered.
Here is the fun experiment with running spiral bulb on electronic power supply (ballast).
Please note: I twisted both wires on each end and thus shorted filaments on each end. So in this case filaments used as cold cathode.
You will have to use very small power ballast in those experiments for E26 bulbs. I would try to find 10W ballasts and if you can't find those one, you might work with 20W, but bulb might go bad very fast. The reason why is because small spiral filled with gas doesn't have enough space to dissipate extra heat from over-running which too much power and they get hot very fast. It could be only 15-30 seconds and they reach over 100C. After this the seal around end wires (between glass and wires) gets loose and air comes inside when they cool down. One way to deal with that is to implement current limiting. But you ether have to put huge wattage resistor (we talking about 20W resistor) or with tricky way to use inductance, like they use in 110AC fixtures. But keep in mind those electronic ballasts oscillate at 15-40Khz not at 60Hz.
Here is some more fun with glowing fluorescent tubes.
Please pay attention, 4T or even 5T base tubes are small and have the same issues that their small relatives E24 tubes. They can get hot with higher power ballasts and burn
Here is even more fun with running UV light bulb. As I explained, there is not much difference between CFL and heated cathode based UV lamp. Connection is the same as for CFL bulb.
Currently we have only power supplies (electronic ballasts) for CFL or UV bulbs which has heaters inside. For CCFL (Cold Cathode or NO filament) lights you need little higher voltage or around 900V to start. So if you see only two wires bulbs, they are need special CCFL driver. We will try to carry those soon.
Here some more fun with lighting many different lamps with the same electronic ballast