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ZakWolf

Tue Jun 11 2013, 07:59AM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

so I received all my parts finished the driver and fired it up... No mosfet exploded, but the board produced no heat or sound.

I found out that i had a faulty cap for one of the ucc chips, no more shorts...

The 555 timer is working making an led blink and various speeds and duration's but the bridge isnt drawing any power.

That means something is wrong with my UCC chips ? If its not switching any power it means its not being turned on, correct?

EDIT: is there anything i can measure with my Multimeter i dont have a scope :(

Physics Junkie

Tue Jun 11 2013, 11:32AM

Registered Member #7267 Joined: Tue Oct 16 2012, 12:16AM
Location: Detroit, Michigan
Posts: 407

If you don't hear thus GDT buzz then possible wired the GDT wrong or something wrong the the UCC chips. You could check to see if your chips are dead with the resistance/continuity function. Did you use a 12V reg for the gate drivers? Check that the gate drivers are receiving the proper voltage too

ZakWolf

Tue Jun 11 2013, 09:12PM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

Physics Junkie wrote ...

If you don't hear thus GDT buzz then possible wired the GDT wrong or something wrong the the UCC chips. You could check to see if your chips are dead with the resistance/continuity function. Did you use a 12V reg for the gate drivers? Check that the gate drivers are receiving the proper voltage too

I do hear a small click sound every time the 555 gives out a pulse.

Which pins do i check with the continuity function to make sure there ok ?

Mads Barnkob

Tue Jun 11 2013, 09:39PM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

Sigurthr wrote ...

My main 2.25kW SSTC is based on this coil and runs CW on full wave rectified and filtered 120Vac input regularly with run times over 5min. I used this design as a template and simply added a few additional safeties and upgrades like lower RdsON MOSFETS (FDL100N50F) and gate protection zeners. The main change I made was using a 12V version of the 74HC14 and a heavier gauge primary (gets hot!). It just takes a VERY solid half-bridge construction to handle the power safely.

It handles CW duty very indeed :)

From 1:40

ZakWolf

Tue Jun 11 2013, 10:39PM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

When I just have the driver side powered up, i hear the fast click sound(really quite) and i started taking some voltage readings with my Multimeter.

I am getting 1.6v across the drain and source pin of one mosfet and 2v across the drain and the source pin of the other . All chips are receiving the correct voltage and nothing get warm.

I replaced the 74hc14 chip and now both ucc chips are pulsing correctly and( before only one had an interrupted out put) I am feeding the H-bridge side 45v and its not doing anything, the fets i assume are not turning on at all, once the smoothing cap cap is full there isnt any current draw.

EDIT: With a speaker on the H-Bridge output i can get a small buzzing sound that i can vary with the pots. Im starting to think i am missing a connection with my main power input

ZakWolf

Tue Jun 11 2013, 10:52PM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

Got it!!!! I was using the continuity setting and i found that i one of the 5ohm resistors wasnt connected, it tested fine when connected directly, so i bridged the gap and it started occilating loudly (the speaker) so i connected it to the secondary and it started lighting a florescent tube, no break out yet though

EDIT: BREAK OUT !!!!

Physics Junkie

Wed Jun 12 2013, 12:41AM

Registered Member #7267 Joined: Tue Oct 16 2012, 12:16AM
Location: Detroit, Michigan
Posts: 407

Glad to hear!

ZakWolf

Wed Jun 12 2013, 06:52AM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

Ok so im not really sure how to tune this coil.. I get only 6mm break out with 120v (no top load) but when i hole the anntena I get like 1cm, I have tried moving the antenna around its only 18cm long (~7in) long. does it need to be longer?

Also the mosfets get hot quick, im sure its because it needs to be tuned. I have 10 turns on the primary

Physics Junkie

Wed Jun 12 2013, 07:00AM

Registered Member #7267 Joined: Tue Oct 16 2012, 12:16AM
Location: Detroit, Michigan
Posts: 407

remove like 5 turns or so. you should not need that many turns. the schematic says to use 4 turns

ZakWolf

Wed Jun 12 2013, 07:16AM

Registered Member #3114 Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608

Haha got it already, Im at 7 right know its im getting about 4 in sparks, SSTC are way cooler then plain old SGTC....

This is awesome ! :D I will post pics soon thanks for all the help

EDIT: I cant draw arcs?? when I bring something near the output i get a really thin white spark and then there is no output

EDIT:**********VIDEO!!!!!

*********************

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