flourescent tube fittings using a choke not a starter

[tadpole]

How does a choke (NOT a starter) cause the tube to work. Is there a simple fault finding procedure? (fuses check OK) There is power to all wires and both ends of the choke. New tube but no light. Glad of some advice.

[ACB312]

As far as I understand, a normal fluorescent tube is struck by a high voltage across the electrodes at either end of the tube by the action of the starter capacitor collapsing the voltage across the choke (a large coil) and thus inducing a large reverse voltage which strikes and starts the current through the tube. I have used electronic starters (about �4 each) in all my fluorescent lights for over twenty years and have never replaced a tube yet. Back to your question - when you stop a current through a coil, a back emf (electro motive force) is generated which can be many times the original voltage applied to the coil depending on the speed of the switching and thus applies a high voltage to start the fluorescent process, Your choke should measure (if you have a good meter) only a few ohms resistance. Hope this helps, if too technical get back to me and I'll try again.

[qapmoc]

The choke has two functions, one as above which generates a high voltage pulse to start the tube conducting, but then as the arc is established and the gas heats up its resitance will decrease and the current will rise until it destroys the tube unless something acts to reduce the current, that something is the choke which will oppose the build up of current and stabilise it at a working value.

An easy way to check out a choke without test equipment is to connect it in series with a filament lamp (230v/40w is OK) and connect it to the mains live+neutral when the lamp should come on dimmer if the choke is OK.

In series means -
choke light
Live-------|||||||--------(~)---------Neutral

[qapmoc]

Sorry, try this (stupid system removes empty blank spaces)

...............choke.......light
Live-------|||||||--------(~)---------Neutral