Overdriving NO

[sammydee]

I got two 36 watt electronic ballasts off ebay. They are Quicktronic ballasts made by osram and each can power two 36 watt bulbs. I hooked up each lead to a bulb so that 36 watts is going to each one, but when I checked it against an 18watt magnetic ballast I couldn't tell the difference in light intensity except that the electronic ballast seemed "softer" if anything.

What am I doing wrong? Should I be getting BOTH of the 36 watt leads from each ballast and connecting them to one light each so it is getting 72 watts?

One thing: with the electronic ballast the bulb ran WAY hotter. Dunno if this means anything .

I'm pretty confused can somebody help me please?

 

[sammydee]

I did a load of research and reading and figured out what it is (I think). Please correct me if I am wrong.

An electronic ballast has a feedback mechanism - a 36 watt ballast (for a 48" tube) will drive a 24" tube at the same brightness as the 48" tube because it has this feedback mechanism.

So, the tubes are not being driven any brighter than normal. What I intend to do now is to hook up BOTH 36 watt outputs of the ballast to ONE 24 watt bulb. This would then overdrive it twice.

What I am not sure about is that if I hook two 24" bulbs in series, that makes 48". So... if I treat the two bulbs in series as one long bulb... I should be able to overdrive it with one ballast to 36 watts each... am I right?

This means I could get four bulbs and run them all at 36 watts each from two 2-36 ballasts, getting around the problem of the feedback mechanism.


Have I just confused myself even more or would that work? C'mon great lakes, your the expert on ODNO...

 

[sammydee]

I think I made a mistake about connecting the bulbs in series, because then the two middle coils would not heat up when the tube was starting up, and that could cause problems.

What I am thinking about doing instead, to get around the feedback problem, is to do something like this:

This is the normal ballast wiring. The feedback mechanism is restricting the wattage flowing through each bulb from 36watts to 18 watts:

Here is one bulb overdriven. The ballast still puts out 18 watts but because it has both of its leads attached to the bulb it adds up to 36 watts, overdriving it 2x:

Here is my original idea for overdriving in series to get around the feedback problem and making the ballast think that the two 24" tubes are one long 48" tube. However I do not think this will work because the two left hand coils will not be heated up:

This is my final idea. Because each lead connects to two bulbs, it makes the ballast think it is dealing with one 48" bulb rather than one 24" bulb, and because the other leads are spliced together, it should put 2x 18 watts through each tube.

Have I done this right?

I don't want anything to explode or catch fire.

 

[sammydee]

I don't suppose anybody was very interested in the ideas I put forward but I'd just like to say for the record that the tubes connected in series DOES work. One coil is enough to ingnite the whole bulb, apparently.

 

[Ed4567]

Been trying to get my head around this. With the tubes in series have you suceeded in overdriving them, i.e. are they brighter than before? I can see the logic of how it would work, but it would depend on how the feedback system is designed.

 

[sammydee]

Yes they are WAY brighter than before. I'm wondering if my original idea of adding another 72 watts of light is really worth doing. I'm glad I installed two cooling fans because those tubes are really pumping out some heat.

I'm not sure how the feedback mechanism works, but this has fooled it and the lights are very bright B) .