Ballasts?
- Thread starter Hoyt
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winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
A fluorescent lamp works by having current flow through the gas from one end of the tube to the other. To get this current flow, electrons need to leave electrodes on either end of the lamp, and during steady state operation, this requires the electrodes to be warm.
The difference between 'rapid start', 'instant start', and 'program start' has to do with how the electrodes are heated and how the current flow through the gas is initiated. The different ballast types have different trade-offs between operating efficiency, lamp life (and number of starts), and ballast cost.
The electrodes themselves are actually often filaments, and can be heated by passing current through them (thus the _two_ pins on each end of some lamp tubes). The current flowing from one end of the tube to the other will also heat the electrodes.
http://www.unvlt.com/literature/programmed.html
Very roughly: a 'rapid start' ballast uses a current through the electrodes to heat them up to permit the current to flow between the electrodes; eventually the electrodes are hot enough to get glow current flowing between them. An 'instant start' ballast uses a high voltage between the electrodes to initiate the glow current, without direct heating of the electrodes. A 'program start' ballast uses a combination, and adjusts the electrode heating between start and run; this maximizes bulb life and efficiency, but costs more.
-Jon
The difference between 'rapid start', 'instant start', and 'program start' has to do with how the electrodes are heated and how the current flow through the gas is initiated. The different ballast types have different trade-offs between operating efficiency, lamp life (and number of starts), and ballast cost.
The electrodes themselves are actually often filaments, and can be heated by passing current through them (thus the _two_ pins on each end of some lamp tubes). The current flowing from one end of the tube to the other will also heat the electrodes.
http://www.unvlt.com/literature/programmed.html
Very roughly: a 'rapid start' ballast uses a current through the electrodes to heat them up to permit the current to flow between the electrodes; eventually the electrodes are hot enough to get glow current flowing between them. An 'instant start' ballast uses a high voltage between the electrodes to initiate the glow current, without direct heating of the electrodes. A 'program start' ballast uses a combination, and adjusts the electrode heating between start and run; this maximizes bulb life and efficiency, but costs more.
-Jon
boboelectric
Senior Member
- Location
- Eighty Four,Pa.15330
How about a quick class on Pulse strart Metal Halide Fixtures.
cadpoint
Senior Member
- Location
- Durham, NC
- Occupation
- Electrician - but not by NC Law.
Wait now
I thought one terminal end was postive the other is negative, that creates not so much a current flow as a stream of various electron's flowing from the ends that ignite the mercury+argon vapors, your basic atom smashing event or at least collision that we see as viewable light.
A low scale nuclear event !
Basic light physic's also as I remember it, as light goes forward it also goes 360?, I'll get back to ya'll later on that...
By hey thats all from memory...honest... and didn't recall argon being in the mix. I had to look this up just the same. I like this one... http://www.howstuffworks.com/question337.htm
I thought one terminal end was postive the other is negative, that creates not so much a current flow as a stream of various electron's flowing from the ends that ignite the mercury+argon vapors, your basic atom smashing event or at least collision that we see as viewable light.
A low scale nuclear event !
Basic light physic's also as I remember it, as light goes forward it also goes 360?, I'll get back to ya'll later on that...
By hey thats all from memory...honest... and didn't recall argon being in the mix. I had to look this up just the same. I like this one... http://www.howstuffworks.com/question337.htm
cadpoint
Senior Member
- Location
- Durham, NC
- Occupation
- Electrician - but not by NC Law.
Think of it another way, they now build the ballasts with chips and the simple application of appling P=IE with the use of these chips, and the voltage level of ballasts, one can gain many variables...
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