Author Topic: Testing BT's home-made fluoro circuit  (Read 3506 times)

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BT Humble

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Testing BT's home-made fluoro circuit
« on: April 05, 2005, 10:05:51 PM »
I decided that it was time to do a burn-in test on my home-made 15W fluoro:



...so I've hooked it up to a small 12V system and switched it on.  As of this morning it was using 850mA (I tweaked it a little since the above photo was taken, to make it a little brighter), and had been running for 65 hours without any issues.  It's a little brighter at one end of the tube than the other, but I think that's just due to the way the circuit works.


Here's the construction article:


http://www.fieldlines.com/story/2005/1/31/234116/315


BTH

« Last Edit: April 05, 2005, 10:05:51 PM by (unknown) »

BT Humble

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Re: Testing BT's home-made fluoro circuit
« Reply #1 on: April 06, 2005, 04:36:08 PM »
Up to 85 hours now, and all is well.


BTH

« Last Edit: April 06, 2005, 04:36:08 PM by BT Humble »

RobC

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Re: Testing BT's home-made fluoro circuit
« Reply #2 on: April 06, 2005, 10:04:15 PM »
Looks like it will work just fine. I stopped worrying about my setup at 75 hours. Mine by the way can be adjusted from a dim setting to the full output 50 to 75 watts depending on what you want. And you know what, it never would have happened without your starting the thread many thanks. RobC
« Last Edit: April 06, 2005, 10:04:15 PM by RobC »

RobC

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Re: Testing BT's home-made fluoro circuit
« Reply #3 on: April 06, 2005, 10:06:02 PM »
Make that 20 to 75 watts.RobC
« Last Edit: April 06, 2005, 10:06:02 PM by RobC »

BT Humble

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Re: Testing BT's home-made fluoro circuit
« Reply #4 on: April 06, 2005, 10:18:01 PM »


Looks like it will work just fine. I stopped worrying about my setup at 75 hours. Mine by the way can be adjusted from a dim setting to the full output 50 to 75 watts depending on what you want. And you know what, it never would have happened without your starting the thread many thanks. RobC


I've bought a few 555 chips to try out your circuit too, hopefully some of these zillions of ferrite transformers I've extracted from old computer PSUs will have windings that will work unmodified.  It seems a shame to dump them, and they're almost impossible to disassemble for rewinding.


I think I've worked out a method for a brightness adjustment for mine too, although it sort of defeats the whole idea behind it (low parts count (of recycled components), simple, cheap).


BTH

« Last Edit: April 06, 2005, 10:18:01 PM by BT Humble »

RobC

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Re: Testing BT's home-made fluoro circuit
« Reply #5 on: April 07, 2005, 08:55:35 AM »
Use the core out of the flyback transformer. It should come apart easily; just make a cardboard bobbin to wind the wire on.


RobC

« Last Edit: April 07, 2005, 08:55:35 AM by RobC »

BT Humble

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Re: Testing BT's home-made fluoro circuit
« Reply #6 on: April 07, 2005, 07:44:00 PM »


Use the core out of the flyback transformer. It should come apart easily; just make a cardboard bobbin to wind the wire on.



I'll give it a try.


BTH

PS - This afternoon will be 5 days of continuous running. I think I'll switch it off on Sunday evening. ;-)

« Last Edit: April 07, 2005, 07:44:00 PM by BT Humble »

sandovalch

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Re: Testing BT's home-made fluoro circuit
« Reply #7 on: May 16, 2005, 12:10:00 PM »
The circuit works, I'll make the printed circuit and assembly it for real and try it out for a longer period of time.

« Last Edit: May 16, 2005, 12:10:00 PM by sandovalch »

BT Humble

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Re: Testing BT's home-made fluoro circuit
« Reply #8 on: May 18, 2005, 12:03:45 AM »
I've found that increasing the value of the 1/4W resistor to 200 ohms or so is a more effective way of reducing the circuit's current draw.  Also, if you want to drive a 36W (4 foot) tube, use an MJE3055 transistor and wind an extra 150 turns or so on the secondary (ie. 600 turns rather than 450).


BTH

« Last Edit: May 18, 2005, 12:03:45 AM by BT Humble »