Replacing Fluorescent Starters

[revolution1]

Hello everyone, simple question, but I don't know the answer to it.

When replacing the starter on a florrie light, what happens if i over/under rate?

I.E. Any advantages/ disadvantages to using 4-22W starter on 100W tube? Or vice versa?

Thanks, Revolution1.

 

[Job_n_knock]

It would probably be easier to explain the princible of flourescence, you should then be able to work it out yourself...assuming you have Electrical training. When mains voltage is applied to the flourescent circuit, the starter (which is basically a switch) allows current to flow through the electrodes of the tube. The current causes the starter's contacts to heat up and open, this interrupts the flow of current which causes a great increase in voltage in the choke (or ballast) which eventually (it doesn't always work first time!) causes the tube to light. Since the gases in the tube have negative resistance, the choke now plays the role of a current limiter. The capacitor is sometimes used to get voltage and current back in phase. So if you havent yet worked it out, if you use a starter with a rating too low, it will not last very long, a starter too highly rated simply wont be able to heat up enough for the contact to open. I should explain that when the high voltage is applied, this causes mercury (i think) to emit UV light which causes the coating on the side of the tube to glow. Among other gases theres argon. I dont think Ive missed anything out but if I have.... someone here will soon jump in Ive no doubt

 

[Lectrician]

Indeed it's mercury - the floury is a "Low Pressure Mercury discharge Lamp" MBF's are "High Pressure Mercury".