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skmetal7

Sat Feb 11 2006, 11:04PM

Registered Member #101 Joined: Thu Feb 09 2006, 08:12PM
Location: Wisconsin
Posts: 41

take a look at this video and tell me if you can see whats wrong. (note, i'm powering it with 43 volts @ 5 amps)

http://media.putfile.com/cool-010

well anyway, i was planning on posting some flyback arc pics, when i turned on my zvs, drew some nice arcs, then it just stopped. now the only way i can draw anything is if i touch both leads together and pull about 1/2" arc. i have no meter to test anything, i have not changed anything since last time i used it, still using the same trans. that i normally use. i'm guessing that i maybe blew a FET?? nothing is warm, and i tried a few diff. caps, but nothing. maybe im just having a bad week

Mike

Sun Feb 12 2006, 02:00AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

I have problems like this alot (mainly due to wild testing)
Usually it is the IGBT's or Fets, if you got 2 extras try replacin em
But you realy need a meter to check for contuinity between pins. Also, I some times have trouble with those damn zeners, so If you got extras try those to. Otherwise my other components don't fail.

Part Scavenger

Sun Feb 12 2006, 02:16AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

No meter!? Goodness! This is the first thing every geek needs! Even a 4 dollar Harbor Freight digimeter is better than nothing. I would REALLY consider getting a meter. Actually the HF one is a pretty good deal. They have a 30-40 dollar one that is as accurate as my 200 dollar meter and it comes with a capacitance meter.

Check you fets for cracking/oozing (it may very small.) If not, this is when you need a meter to check if they have failed D/S. Your zeners could have fried too.

HV Enthusiast

Sun Feb 12 2006, 04:00AM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

wrote ...

well anyway, i was planning on posting some flyback arc pics, when i turned on my zvs, drew some nice arcs, then it just stopped

I just wanted to clarify what ZVS is as i am seeing this term misused quite a bit lately. ZVS is not a type of circuit, flyback driver, or similar. ZVS stands for zero voltage switching and is an operational condition only. If a FET is switching when the voltage across it is zero, than that FET or other device is said to be operating in a ZVS condition. So when you say "i turned on my zvs", that doesn't really make sense.

Also, your flyback driver could work just fine and not being operating in a ZVS condition. You won't be able to tell this from operation unless you actually looked at the switching with an oscilloscope.

Anyways, not trying to be harsh, just attempting to correct some of the terminology being used here.

skmetal7

Sun Feb 12 2006, 04:49AM

Registered Member #101 Joined: Thu Feb 09 2006, 08:12PM
Location: Wisconsin
Posts: 41

opps sorry, i hear everyone say "the zvs driver", or "zvs circuit" so that is what i thought it was called. so what is this circuit called anyway? flyback driver? but if i say that then it could mean a few different circuits...

ok so the flyback driver that opperates in a zvs condition, is giving me problems.

Part Scavenger: see my thread in gen. science / electronics > "A part of me just died", then youll know why i dont have a meter (warning: you might shed a tear)

HV Enthusiast

Sun Feb 12 2006, 04:53AM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

wrote ...

so what is this circuit called anyway?

I guess the proper term would be "ZVS flyback driver." Anyways, i wasn't trying to nitpick

- i'm sure everyone on the board knows what you mean when you say ZVS, but i just wanted to correct the terminology.

Hope you can get your meter fixed.

Part Scavenger

Sun Feb 12 2006, 02:00PM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

I'm sorry, I didn't know...

Kolas

Mon Feb 13 2006, 03:01AM

Registered Member #102 Joined: Thu Feb 09 2006, 08:15PM
Location: Raleigh, NC
Posts: 169

Ok, doesn't seem like an answer was rendered.
I'm willing to vote the flyback is shorting internally.
so it might be dead.

Either that or the internal primaries that never have a load have broken down their insulation. Also killing the flyback.

Kolas

...

Mon Feb 13 2006, 04:30AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

Is putfile back up yet?

Are the sparks nice and hot? If they are weak and blue then I would check your tank cap (disconnecting it gives crappy blue sparks)
Also check the primary connections, a loose one can cause problems...

But it is probably the flyback

Did it ever get very hot during your testings? They don't like the abuse of 300w going in...

skmetal7

Mon Feb 13 2006, 06:38AM

Registered Member #101 Joined: Thu Feb 09 2006, 08:12PM
Location: Wisconsin
Posts: 41

ok check the link above. i could try a diff. flyback, the one i use doesn't get hot, its big though! i tried a few caps but nothing. i only had it on for a few seconds, so i dont know what happened.

EDIT: well it looks like kolas called it, it was the flyback. tried an ac one i had lying around and it produces some crazy arcs, ill post them later. it must have been on its last leg though, i never ran it more thatn a few secs. and no where near 300w. it was from a pretty old tv.

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