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flyback ignition help.

Posted: Sat Aug 18, 2007 1:06 am
by Blackett
Okay, i have successfully at least managed to identify the flyback component in this junior tv, but It is soldered to a particularly large circuit board, and I need help identifying which other components are needed to power the flyback. The bottom is just soldered about 6 times through the board with no wires that i see. :( which makes my job somewhat more difficult.

anyhow here are some pics, and im sure one of you gurus knows significantly more about what else i need to remove. Also, required volts to obtain the constant spark again. previously it was running off the 120v outlet adapter. here are some pics, and thank you.


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(flyback black thing to right)


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Posted: Sat Aug 18, 2007 1:20 am
by CannonCreator
Dude thats a mess! I have no clue what to look for on the board, I can do flash ignitions though. Sorry dude I can't help.

Good Luck! sry.

Posted: Sat Aug 18, 2007 1:29 am
by Blackett
hah your telling me. if worst comes to worst i could rip the damn thing out and play with the grounding at the bottom as a learning experience.

Posted: Sat Aug 18, 2007 2:16 am
by CannonCreator
um........ :lol: what?

Posted: Sat Aug 18, 2007 3:03 am
by Copperboy
http://www.angelfire.com/80s/sixmhz/flyback.html

A great tutorial, although I'm having trouble with my rig (didn't get the right kind of transistor)

Posted: Sat Aug 18, 2007 3:30 am
by spud yeti
I think you should have sold the TV and used the money to buy a camera flash ignition :wink:

Posted: Sat Aug 18, 2007 11:16 am
by singularity
your gonna need like a heat gun or a soldering iron and a solder sucker to get that thing out. all your gonna need from that board is the flyback don't worry about anything else from the board (except the big heavy duty red wire). its a huge pain to get big multi pinned components out of a board but it is possible. you don't need all to much voltage to power one of those 12v should be fine. look at the link copperboy put up it shows how to wire it and which transistors will work.

Posted: Sat Aug 18, 2007 1:35 pm
by jimmy101
If you don't have a solder sucker a can of compressed air, or a blowgun on a compressor, work very well for unsoldering stuff. Heat the joint with the soldering iron then blast the molten solder away with the compressed air. In my experience this works better than desoldering braid, or a solder sucker, in cases where you don't care about trashing the circuit board.

There should be a power transistor (or two) somewhere on the circuit board. That transistor is the one you need. You can buy suitable transistors online but why bother when the TV already has the exactly correct transistor?

Look for a heat sink (hunk of metal, sometimes with fins or slits) with a single transistor (three wire device, with a metal backing plate) screwed to the heat sink. One of the traces on the circuit board, or a wire, should lead from the transistor to the flyback. You want both the transistor and the heat sink it is mounted on.

You might also want that big-ass resistor in the first photo. Looks like it is about a 20 Ohm one. IIRC, the flyback circuits need one (or more) low resistance high wattage resistors. The resistor is bottom center of the first photo, a light blue (?) cylinder with a wire on each end and stripes (but no numbers) on it. One of the stripes is gold colored, it looks like the other stripes are red, black and brown.

Posted: Sun Aug 19, 2007 2:25 pm
by Blackett
okay you guys have been a great help.

I got the components out in one piece and found that a pencil torch did the trick pretty well.

Im just glad i didnt have to do something retarded like look for a giant project box.

thanks again.

Posted: Sun Aug 19, 2007 8:29 pm
by Blackett
okay now that I have it out it has two knobs that say resolution and screen, I have identified the coils, and it also has two other wires coming out of it that I believe have something to do with the knobs, but as of now remain unsure. and I am still clueless as to how to get the thing to create the steady stream of voltage.


that turorial was some help but i am slow i guess.



transisters:

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board. i dont know if i need anything els eoff of here. I got the transister but not the heat sink.

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bottom of flyback:
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and another pic of board. excuse the incredibly crude method of removing the fkyback. (the gaping tear)

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Posted: Sun Aug 19, 2007 9:18 pm
by sjog
All that to get a spark, does'nt make sense.
Battery BBQ igniter--cheap easy to use

http://www.appliancefactoryparts.com/ga ... _ign1.html

Posted: Sun Aug 19, 2007 9:26 pm
by iPaintball
The flyback you have is one of the newer ones, so it probably has a rectified output. One some flybacks, you can remove the rectifier, (it looks like a little tube sticking out of the flyback) but on others, it is potted in epoxy, and can't be removed. This isn't always a bad thing though. If you plan on using it for an ignition, it shouldn't matter, but if you want to use it for other things requiring AC such as plasma globes, forget it. You can use it to charge caps though. Here's a very simple circuit courtesy of Powerlabs that can be use with the readily available N3055 transistor: Image

Posted: Mon Aug 20, 2007 9:25 am
by jimmy101
iPaintBall's post is a good idea. With a little luck you can use the transistor that you salvaged from the TV as the 2N3055. (And heck, if you fry it it didn't cost you anything).

With some luck the big ass resistors from the TV can be used for R1 and R2. Note that both those resistors are high wattage types. (Generic reistors are rated at 0.25 watts). 1W is big, 5W is really big. The exact values (in ohms) of the resistors is not critical, either can probably go up or down by perhaps 50%. You can use a higher wattage resistor in place of a lower wattage one. If you use a lower wattage resistor the circuit might be useable for short periods.

The heat sink from the TV is probably a good idea. The power transitor will get hot and cook itself. Without the heat sink the circuit can probably be run for a second or so then it'll need to cool off. With the heat sink, and using the same voltage the TV used, it should be able to run continously since that is what it did in the TV.

Big fun, post what you get it to do, and be careful. Naturally, the HV output can hurt you. In addition, 24V across 240 Ohms is 0.1 amp, more than enough to "get your attention" if you touch the wrong thing.

Posted: Mon Aug 20, 2007 5:58 pm
by Blackett
okay will do. but as for the all that for a spark post, i enjoy challenges. besides. a tiny millisecond of elctricity is no match for a 2cm stream of plasma o.O

anyhow, thanks again.

besides its hard top a fit a long bbq ignitor into a a handle of sorts, so intend to use a momentary switch.

Posted: Mon Aug 20, 2007 6:27 pm
by sjog
Hey that's great! I'm just not smart enough to do that kind of work! There are plenty of people on this site that can do that stuff.
The only time I messed with fly back was to get the wire and really did'nt need it.