Flourescent lamp problem

[zipper]

Can anyone point me to a link showing a typical circuit diagram for a single tube fluorescent light with magnetic ballast choke?
This lamp is on a cooker hood (unfortunately most of the wiring has been disconnected/clipped by the previous owner & no diagram exists). The lamp has 1 tube, a single pole switch & a tridonic magnetic ballast choke. There does not appear to be a starter or capacitor & there is no connection drawing on the choke itself.
This is not my particular field but I thought most magnetic chokes were just a simple series inductor inline with the tube. There are only 2 terminals on the choke, one is marked "L" & the other "Lamp". There is evidence of only 1 wire ever being connected to the "L" side, but there are 2 clipped wires exiting from the "Lamp" side of the choke. This is what throws me off a little since I thought chokes were inline devices.
Anyhow, if some kind person could help shed some "light" on the subject I would be most grateful.

 

[Adam_151]

How many pins does the lamp have?

 

[zipper]

Hi Adam, The tube is a single pin type.

 

[Adam_151]

Single pin at each end you mean?

I'd imagine you just wire it in series with the choke (Live to L of choke, then from other terminal to lamp, out the other end of lamp to neutral)

 

[zipper]

Yes a single pin each end, sorry if I was perhaps a little unclear there.
I also thought it would simply be wired in series but what threw me off was that there appear to be 2 clipped wires (original wiring) on the lamp output side of the choke. I will get a new choke/tube, change them both out & connect in series & see what happens. I was taken by surprise by the fact that there does not appear to be a starter in the circuit. I thought there would be when the lamp has a pre-heat ballast. Or am I wrong?

 

[bernardgreen]

Here is a starting point for the information

http://www.tridonicatco.com/kms/cms/kms.php?str_id=716

TridonicAtco UK Limited
Basingstoke
Hampshire RG 24 8LB
[email protected]

 

[Adam_151]

No sure what the other wire leaving the choke is (though its not been cut *really* short and what you are seeing is where a wire as been double over or anything like that, are you?)

IIRC, smaller tubes have no need to pre-heat (and on a tube with only 2 pins there is not anough connctions for it to have the pre-heat filaments anyway), and start straight off.

Trying to bring to mind whats inside a 2pin 16w 2D fitting, you don't generally take much notice of them when you're just fitting them though

 

[zipper]

Adam, Thanks for your time & assistance on this one. Maybe it was just a double over as you suspect, there isn't a great deal else in there to connect anyhow. I'll hook it up when I get the new parts. Thanks for the valuable pointers!

 

[bernardgreen]

Trying to bring to mind whats inside a 2pin 16w 2D fitting, you don't generally take much notice of them when you're just fitting them though

The 2 pin version has (apparently ) the same type of 4 terminal tube as a 4 pin version but has a starter between the two tube terminal that are not bought to pins.

 

[333rocky333]

What shape is this tube with one pin each end, there are very few straight tubes like that, that operate via a choke.

 

[zipper]

Thank you all for being so kind in replying to this post. This not being my field I fear I may have supplied misleading information regarding the tube. It does have 1 pin each end of the tube...but the tube is "U" shaped (11W). Bernard mentioned an internal starter, could this perhaps be encased in the small plastic block where the pins actually protude? If so it must be very small indeed.
I checked out the Tridonic link & found a diagram; the choke (an EC9-A27) certainly does appear to be connected in series. I have already checked continuity between the 2 terminals of the old choke & found none. This morning I got a new choke & checked continuity on that...none on that one either. Now I am a little confused, is the choke coil one continious winding? (which I guess it should be otherwise it serves no purpose).

 

[333rocky333]

Is this the lamp.

http://www.haysomlighting.co.uk/item--BEPL11W---11-Watt-2-Pin-PL-Bulb--PL11W.html

It is a pl-s lamp

This has the starter built in.
And you connect as you say Live-choke-Lamp in, lamp out-Neutral.

http://www.leonardo-energy.org/drupal/files/root/Images/ballast/Grundschaltung_glimm.GIF
Ignore the starter bit.

Is there a neutral terminal near the choke, it may have had a PFC capacitor connected between the live at the choke and neutral originally,and may explain the second unknown wire.
It is not unheard of to find L and Lamp connections reversed on a choke.

The live and the pfc lead being in one and the lamp output in the other.

 

[zipper]

Yep, that's the tube & that's the way I hooked it all up. If there ever was a pf cap it has disappeared along with most of the original hard-wiring. Regardless of pfc I can't see how I will ever get voltage across the lamp with an open circuit choke coil, or am I misunderstanding how a choke actually functions? It could simply be an unlucky coincidence & the new choke is defective.
This thing isn't mine, I'm just trying to help help out a friend. I think we've all tried hard enough now, maybe it's time to call it a day.
Thanks for all the help...everyone!
Have a great Saturday night.

 

[333rocky333]

A choke contains miles of very fine wire, and i think they now contain bits to conform with recent EEC rules until they ban them.
It may be your meter unable to test through it.
The easiest way is to fit it as you say, and try it.
There would be when tested a voltage between the lampholder pins, but not recomended unless your competent and have the appropriate test gear

 

[RF Lighting]

You should get continuity across the terminals on the ballast using a low ohms meter.

If not, maybe the ballast is faulty?