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Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
I just got a decent sized TV that was broken, but the flyback still works (the screen was all fuzzy and impossible to clear). Now when ever i try to draw arcs (the driver is whatever is already on board), i get a short bright arc when i get close enough. Then the flyback shuts of, and after a few seconds, turns back on. Will that be a problem when i seperate it from the board and use a different driver?
How can i identify the transistor on the TV which is used to drive the flyback? There are several ones with heatsinks.
The flyback is 29.5Kv (says on flyback). The flyback has a *big* green dot, which is the mark of a good flyback (according to a webpage)
EDIT: I got a transistor off, its the biggest one and close to the flyback, it has D2578 1H3 on it. How can i identfy BCE?
On a side note, is there any chance i can use the electron gun?
Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
Does the resistor go before or after the flyback? (driver or HV?) What resistance should it be? If its on the driver side, will the single transistor driver have it built in? Thinking the voltage divider would protect it. Do they need to be high wattage resistors?
Sorry for all the questions, dont want to burn this.
Registered Member #1083
Joined: Mon Oct 29 2007, 06:16PM
Location: Upland, California
Posts: 256
Take the number on the face of the transistor and go to a site such as alldatasheet.com and punch it in. You should get a few results with a pdf datasheet.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
I strongly suggest you to build a better driver, search "zvs flyback driver". The reason is that the transistor in the TV is useless for driving flybacks at lower voltages, it gets very hot and the output arc is ofter just very small.
Registered Member #1361
Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305
Yeah, even the "single transistor" driver will work better. It worked really well for me, and since its self tuning it doesnt take much to get it to work.
Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
i think i burned the transistor =/
Im just trying to get this to work until i get a trsnsistor for that driver. I just cant get a 2n3005 (not at radio shack) and shipping online is 6$ ;(.
Dosnt the ZVS Driver burn out alot of flybacks? I wound my own primary on the exposed ferrite, 6 for primary, 3 for feedback.
Edit: i found the BCE of the 2SD2578, it said on the PCB =p
Registered Member #1103
Joined: Mon Nov 05 2007, 06:02PM
Location: Houston
Posts: 80
wrote ... Dosnt the ZVS Driver burn out alot of flybacks?
The potential exists, but if you keep power levels low, and slowly ramp up the voltage then you should be able to drive it near breaking point if you're careful. I'd start out with a mere 12V and work up from there, the flyback will probably start to break down around 30-40 volts depending on how much amperage you're drawing.
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TV Flyback driver
