Search found 8 matches

by Bosium
Wed Nov 23, 2005 4:27 am
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Hi Stephen I agree that heating the cathodes will help in striking, however until I make a workable solution to heat them from the 12V line I will use cold-starting. I dont really care about some black deposits on the end of the tube and if they fail early then I will replace them. I have thrown aro...
by Bosium
Mon Nov 21, 2005 12:42 pm
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Hi Chris

Thanks for the input, I appreciate you taking the time to reply.

What you have suggested will require a complete rethink of what I have developed thus far, I will need to think about it some..

Will post back soon with comments.

Thanks again.
Gareth
by Bosium
Wed Nov 16, 2005 6:42 am
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

I forgot to mention I added the bipolar totem stage, made a HUGE difference as it actually turns the mosfets off hard and so improves efficiency.

I am considering going back to single-ended flyback configuration instead of push-pull.
by Bosium
Wed Nov 16, 2005 6:39 am
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Chris, I noticed the tube draws more current and runs brighter the shorter the pulses are, but I cant make the pulses too short without it drawing tons of current. Do you use a ballast capacitor or inductor? Or do you rely on the inductance in the secondary? I have a 18W tube running at full brightn...
by Bosium
Sat Nov 12, 2005 11:39 pm
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Hi Guys I appreciate your input. I have experimented quite a lot and I have favoured square-wave excitement as it allows for a lot of flexibility in design. My design uses the TL494 switchmode controller IC. I have used this before many times for other projects as it is a good solid device and is ex...
by Bosium
Sun Nov 06, 2005 11:24 pm
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Oh, I forgot to mention that I did NOT gap the core. Perhaps an air gap would help? It is a EI-33 core, a standard type and quite big actually. From an old PC power supply. I have used this exact core wound for push-pull operation before in a car-amp stepup converter. It is my 'test' core. I will us...
by Bosium
Sun Nov 06, 2005 11:04 pm
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Re: Fluorescent Lamp Inverter

Hi Michael J, we run on 220VAC here. However, I want an inverter to drive a tube directly, not one to drive a light fitting. Hi Chris, how do I get higher current with smaller pulses? It makes no sense. Less duty cycle, less current surely. The load is not changing. If you decrease pulse-width then ...
by Bosium
Sun Nov 06, 2005 12:42 am
Forum: General Discussion
Topic: Fluorescent Lamp Inverter
Replies: 25
Views: 4630

Fluorescent Lamp Inverter

Hi All My folks are big into camping and 4x4'ing, as there is a lot to do where I live. My dad has one of these little 12V powered 8W fluorescent tubes with battery clips on the one end that he uses a lot. I recently opened it up to replace the (crappy) wires it had come with from the factory. I was...