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renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 04:43am 18 Jun 2018
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Ended up having to go down to 5k1 and it's happily running @227v Finally got a newer scope, bit late but will help on build no 2.
Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 04:59am 18 Jun 2018
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That scope is much easier to compare that looks good. Without the choke and cap on the Toroid primary you get a wider trace due the 20KHZ from the SPWM not being filtered out.
That wave looks excellent . Do yourself a favour and look at the waveform on each side of the IR2110's, then at the 20 Ohm resistors on the power PCB and then at the 4 sets of MOSFET gates. Know what the should look like will be helpful later on.There are only 10 types of people in the world: those who understand binary, and those who don't.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 06:47am 18 Jun 2018
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Turned out to be a dud tip 41 that caused the fet blow up. Bloody hell brand spankin new parts and the fk'r things don't work, that really pisses me off!!! GRRRRRrrrrrrr
Anyway finally got it making power I won't count my chickens as it needs the other mosfets fitted then retest(could prob skip the retest, they are pretty reliable), then caps fitted and final test.
Still need to fit another 7kw of panels on roof and associated charge controller/s
Forklift battery needs a vacuum hood made and vented to garage roof.
Edit, OH btw that dud tip 41 that caused the blow up, I tested the little sh*t on one of these component testers and it came up fine. Mad told me to scope the signal from the 10 pin and keep following it till it goes bad, anyway that's where it turned to crap, but don't think one of those component testers will assure a fully working part, it must have worked to some degree or it wouldn't have done anything when the inverter was fed with restricted current flow, but it was rooted.Edited by renewableMark 2018-06-19Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 08:38am 18 Jun 2018
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So Mark, you learned something else now, do not trust component testers . Seriously, these things put a very tiny current through the part to make it turn on, you might get a better idea of good/bad transistor with a reasonable current.
If you do not have one already, get yourself a 'breadboard' from your nearest Altronics Or Jaycar dealer or, if you like waiting, from ebay.
With that breadboard you can rig up temporary test circuits without having to solder, so much easier to try different components by just plugging them in.
If it was me (strangely, the only faulty TIP42/42 I ever got was when it blew up due the mosfets blowing for a different reason) I would rig a circuit with a little 12V incandescent bulb - these draw more current than LED's - and turn the transistor on and off a few times to see if it switches that bulb OK.
You might learn a bit about NPN & PNP transistors in the process which, of course, you already know . Klaus
noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 513
Posted: 06:42am 19 Jun 2018
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As known, transistors gain drops under load, so it may have 100 gain a 5ma CE current but with 50ma CE current it might only be 10 (extreme case but point made) . Those transistor testers as klaus said only test a ma's and report what they see.. (actually quite accurate ) however it will NOT test under load... i explained ealier i had a bad batch of power transistors that there no load gain was spot on but would fall over with no where near the load they should have. . Great for non critical signals etc..I think it works !!
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 07:25am 19 Jun 2018
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Mark has done well as a newbie to electronics to get a working set of PCBs and learned a lot in the process. Shows that with persistence you will get there even if some take longer than others with more experience.
Is there anybody that has played with electronics and not seen some smoke?There are only 10 types of people in the world: those who understand binary, and those who don't.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 07:45am 19 Jun 2018
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"If ya aint seen smoke, ya aint built nuthin..."
I used to actually have a 'can o smoke', was it DSE that sold those for a while????
Ralph2k6 Senior Member Joined: 24/09/2017 Location: AustraliaPosts: 129
Posted: 08:47am 19 Jun 2018
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When my tinkering goes wrong, usually transistors just stop working on me. Or on the odd occasion i get a nice little splat happen within a glass fuse.
Nice work there Mark Edited by Ralph2k6 2018-06-20Ralph
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 08:50am 19 Jun 2018
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Thanks guys, I know it took me a while. From a complete novice to rewinding a torroid and getting something running I'm happy with my progress in 6 months. I actually got the Clockman board running way earlier, but a dud switch fooled me.
Fault finding is an art form in itself, Mad's assistance helped me find many a problem. He has been very patient and an enormous help, hopefully I'll have learned enough to be a bit more independent now. Cheers fellas, I didn't think the ride would be so hard but bugger it I was going to see it through.Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 09:37am 19 Jun 2018
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That's the spirit, *never* give up .
Actually, if yours had worked faultlessly first go that would have made the rest of us who studied electronics for years look a bit - you know what .Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 06:12am 20 Jun 2018
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OK got it running on no restricted power and with caps. Did a 1200w test then 2400w test.
@2400w the wave went a little bit funny as per pic. Also no load draw is 1.4A so something is not quite right.
I'll play around with the choke tomorrow and use the infra red heat gun to look for hot spots and scope the signal through again. But it ran the blowheater without going BANG. Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 06:24am 20 Jun 2018
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Have you got the Choke, capacitors and filter in circuit?
Also are you using just one channel on the CRO?Edited by Madness 2018-06-21There are only 10 types of people in the world: those who understand binary, and those who don't.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 06:31am 20 Jun 2018
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Choke and caps no filter. And yes just 1 channell.Edited by renewableMark 2018-06-21Cheers Caveman Mark Off grid eastern Melb
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 07:43am 20 Jun 2018
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with no load the wave did look different, it wasn't as sharp as it was before I put the caps in. Perhaps one of those is dodgey.Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 08:11am 20 Jun 2018
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I doubt it is a capacitor, never seen anything like that, what does look like on your LCD CRO?
Also what is the Idle current?Edited by Madness 2018-06-21There are only 10 types of people in the world: those who understand binary, and those who don't.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 08:31am 20 Jun 2018
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I haven't tried the lcd cro, will do tomorrow. Idle is 1.4A which is a tad high, can't remember what the other one was doing, but I'm pretty sure it was a lot less.
With no load, just the machine turned on the sine looks different than it did before caps. The only changes I made were adding caps and putting on heat sinks to tip 35's on control board and power board. The heat sinks shouldn't effect anything, but I'll take them off, then maybe swap the caps from the other Clockman inverter. That might be a long shot (and a pain in the ass) but they are known working parts.Cheers Caveman Mark Off grid eastern Melb
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 08:37am 20 Jun 2018
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Hahahahahaha only one person in the world could come up with that mate. I need to stop killing chinamen, smashing mirrors and walking past black cats.Edited by renewableMark 2018-06-21Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 08:51am 20 Jun 2018
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Mark, a tip for your CRO:
turn the brightness way down for taking pictures, you can then adjust the focus very sharp. If your camera has it, use a night shot setting.
Handheld camera is always tricky, best on a tripod.
Also, take pics in a darkened room so the screen reflections are less.
About your trace, you should have that 2uF mains cap (next to the little tranny) in place. Take your CRO probe from there. Double check the second channel by turning its input select switch to ground.Klaus
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 09:04am 20 Jun 2018
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Have you tried the other control board you have? Idle current should be around 1A. Can't help thinking there is something in the way you have your CRO set.
I find best results like Tinker says with the camera is turn down the CRO brightness, I find works best with my phone with it so low so you can barely see it. That makes the exposure time increase so I can get a full sweep of the trace in the image.
I would be leaving the caps alone for now at least, see what the LCD cro gives you.There are only 10 types of people in the world: those who understand binary, and those who don't.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 09:26am 20 Jun 2018
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OK, thanks guys, I'll do that and report back.
Cheers.
BTW the torroid did hum a bit with no load, but went nice and quiet @2400W so it kind of tells me it was happy, but that wave looked funny.
I was checking the wave from a 240/12v transformer that was connected at the torroid. That was an extra one I fitted on the torroid itself, so I should be measuring it from the control board, ok, I'll do that tomorrow.
Edit, checked last unit and it had a no load draw of 0.48A, so with the same torroid it should be similar, something is a tad amiss.Edited by renewableMark 2018-06-21Cheers Caveman Mark Off grid eastern Melb
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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. Seriously, these things put a very tiny current through the part to make it turn on, you might get a better idea of good/bad transistor with a reasonable current.
