From: "Da Man"
Subject: Re: fluorescent lamp inverter problem
X-Newsreader: Microsoft Outlook Express 5.50.4807.1700
Date: Sun, 05 Jan 2003 08:09:05 GMT
NNTP-Posting-Date: Sun, 05 Jan 2003 04:09:05 AST
"Eric Y. Chang" wrote in message
> Da Man (email@example.com) wrote:
> : A few things bother me with the tube you have: 1) It's quite odd to have
> : florecent tube with only 1 wire per electrode, 2) no heater, 3) Most
> : electronic ballasts don't have replaceable tubes(a real 10,000 hours
> : the plastic, the electronics (HV breakdown), and the caps won't be in
> : greatest shape + the companys want you to buy a new one) 4) every 2 pin
> : replacement tube I saw had a built in starter. Look for places between
> : pins and the tube where they could hide a small tube about 1/4" by 3/8".
> : So to me it really looks like what is happining is that: you have
> : that ignites and drives the tube with a very differnt voltage waveform
> : what would be used for 120V (or 220V if your far away from here!)
> : So, turning it on, the tube ignites due to a high voltage produced from
> : current limited "driver". Since the voltage is higher then when driving
> : the standard way, the starter keeps ionizing, thus kicking in,
> : shorting out the electrodes (there may not be enough current to make
> : glow), and shutting the lamp down. When the starter cools enough to
> : the contacts are so close together that the hot ionizing gas rapidly
> : again, sucking all the avalible current from the highly current limited
> : supply (no low frequency 60 Hz and no large inductor for a big kick),
> : not allowing the tube to ignite. The contacts in the starter would
> : oscillate at a few times a second.
> Hi Jeff. I looked around a little and found that you are exactly correct.
> Everything you said is correct. This is what I get for leaving out the
Glad you got it working!
> Doing a quick google search revealed that what I erroneously called
> "bi-pin" is actually 2-pin. "bi-pin" actually means 4 pins. The only
> place it means 2-pin is on www.deja.com, where another clueless poster
> joins me in incorrectly applying it to 2-pin tubes. Also, despite the
> fact that I'm sure that I saw a camping lantern with a 2-pin tube, all
> the docs said that the 2-pin compact fluorescent lamps (usually
> Philips PL type) contain an integral starter and are only for use with
> old-fashioned magnetic ballasts. The newer 4 pin (also called bi-pin)
> lamps are for use with the electronic ballasts.
An easy fix to convert it to a 4 pin -> cut or melt a hole in the plastic
box that houses the starter. Then simply cut it out, smash it out, or crack
the glass (break the little tip off to release the gas). Then it will be a 4
pin, with 2 pins possibly buryed inside, which don't need to be used.
> So your explanation is entirely correct. To test it out, I put a 0.01
> uF 1kV ceramic disc capacitor in parallel with the blocking capacitor
> in Sam Goldwasser's document. This is intended to get enough current
> through to get that blasted bimetal strip out of the way. Indeed, it
> worked just great, and the lamp turned on, and stayed on. Just great.
> Nice and bright, and the transistors did not need heat sinking.
> Next time, the correct thing to do would be to use thicker wire and
> much less windings on the secondary, and add an inductor in order to
> give the kick when the integral starter opens. Or, just make things
> simpler and use a 4 pin lamp, wired with the filaments on heater
> windings (the transformer will need one more pair of windings).
Just use the 4 pin setup (convert the 2 pin to 4 pin tubes if needed), it's
easier, and contains less and smaller parts. I must try that bottle necked
> Sam and Don need to update their FAQ's, which are nonetheless useful,
> although slightly incomplete in this matter.
They are a great resorce, but they have been around for a very long time.
Pictures are acceptable now too (which for B/W schmatics, can be made really
small), which were a major hassel wayyy back.
> Again, thanks for your help.
> The thick wire concern was not quite
> correct, and my saturation guesses may have been a red herring.
You have to start somewhere, and it was not a bad guess.