Universal DRSSTC Driver V2.5 (Sold Out) / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

Universal DRSSTC Driver V2.5 (Sold Out)

first previous 8 9 10 11 next last

Move Thread

LAN_403

Kizmo

Mon Jul 15 2013, 06:43PM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

Finally got some time to put one together and of course it doesnt work. First whole driver was latched in OCD trip state and there was no life at all at the gate drive section. It turned out that the OCD comparator was dead (it had 1V on its output all the time and i couldnt set the ref. voltage over 880mV). After removing the comparator both of those problems went away.

Now i get nice pulses to the gate drive section BUT it acts all weird. When i measure GDT primary against board ground both ends of the GDT get nice 24V square wave pulse as expected. Only problem is that those pulses are identical and perfectly in same phase! So the differential voltage over GDT primary is nothing!

This is starting to be pretty annoying. First UD2.1 was big fat fail and now this. All i want is sparks but nope, seems like im stuck with UD1.3

Gregory

Mon Jul 15 2013, 10:14PM

Registered Member #2922 Joined: Sun Jun 13 2010, 12:08AM
Location:
Posts: 226

Why the decision of take out the pulse limiter?

Kizmo

Tue Jul 16 2013, 03:31AM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

For debugging purposes only.

All these problems lead me to believe that i may have one or more bad ICs that are trolling me. UD2.1 didnt work and i never solved that issue. Only common thing between these builds were parts. Im not saying that mouser sells faulty stuff but maybe this box of drsstc parts was little bit too close to my sstc experiments or something.

<- old problems

Just to be sure im going to order fresh set of every semiconductor on that thing and we will see if that helps.

Goodchild

Wed Jul 17 2013, 06:57AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Although this may sounds stupid, do you have the Tl3116 and the LM311 swapped? I only ask because I at one point did this on the UD2.1 and it lead to similar issues to what you were describing.

anyway I'm sorry to hear it's giving you grief... My advice, step through the circuit with a scope and signal gen on the input and check to see where the signal stops being correct.

Lastly your gate signals being in phase sounds to me like you have the phase jumpers set wrong, are both jumpers on the same part of the header?

Kizmo

Wed Jul 17 2013, 06:10PM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

Goodchild wrote ...

Although this may sounds stupid, do you have the Tl3116 and the LM311 swapped? I only ask because I at one point did this on the UD2.1 and it lead to similar issues to what you were describing.

anyway I'm sorry to hear it's giving you grief... My advice, step through the circuit with a scope and signal gen on the input and check to see where the signal stops being correct.

Lastly your gate signals being in phase sounds to me like you have the phase jumpers set wrong, are both jumpers on the same part of the header?

You pretty much nailed it. I had indeed those ICs mixed up. Now it works... just like the UD2.1 i had hard time about a year ago!

primary current vs inverter output voltage

You dont need oscilloscope to tell its not really working..

What kind of sorcery is this?

Same thing as before, i can drop in UD1.3 and it works perfecly.

Goodchild

Wed Jul 17 2013, 08:51PM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Unlike the UD2.1 the jumper by the inductor set a R or RL burdon network. ie you can disable the pheas lead functionality for debugging. I would try setting the jumper so just the R is in the burdon network and try it again.

From your previose scope shots it looks to me like a possible phase lead issue, maybe the wronge size inductor or somthing along those lines. If this goes away when you switch the network to just R this may be the issue.

Kizmo

Thu Jul 18 2013, 04:06AM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

I dont have inductor in place. Same with UD2.1, inductor value didnt have any effect.

Goodchild

Thu Jul 18 2013, 03:13PM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

Without the inductor in place you are basically running that feedback input open circuit. Although technically it has a chopper network I have had bad things happen because it was left open.

Humor me on this, put your scope on the output of the TL3116 (pin 7 or 8) and take a scope shot in these three conditions.

First, just how you have it now, no inductor in place.

Second, with the inductor in place.

Third, with the jumper set such that only the R is in the feedback network.

This will also show if the problem you are having is an issue with that first part of the board which 90% time with these phase lead controllers that's usually where it is. Everything after the TL3116 is simple digital stuff and is usually not the issue.

Kizmo

Fri Jul 19 2013, 05:56AM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

I think this is somewhat complex problem. I see quite a lot of noise at the output of the phase comparator BUT its difficult to tell if its real or just common mode noise. I have to retest it with my differential probe which has very good common mode noise rejection.

Perhaps next test will be with differential probe and battery power for the driver. Right now there is so much common mode noise from bad switching timing that all it takes is a probe touch to the output of the phase comparator and whole thing will go from sort of working to not working at all.

Strange thing is that i have had this problem with two very different setups. First one was with ultra fast 150A semikron and this one is 24h series cm300 H-bridge. Only thing common with these two builds are builder and most of driver side parts.

ivest

Fri Sept 06 2013, 08:15PM

Registered Member #30780 Joined: Tue Jul 30 2013, 07:55PM
Location: Rossendale, Lancashire
Posts: 6

Hey everyone! Love your work Eric. Here is a picture of some of your rev a design just waiting to be populated and used for my coil. Sorry about the quality of the picture it was just a quick snap in less than ideal lighting. There was minimum order so if anyone in the UK wants to buy one then just shoot me a PM. Â£8 including 1st class post.

first previous 8 9 10 11 next last

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob