Re: Power Inverter for a Car (Diagnose + Repair)
In the board there are no shorts, did you want me to yank them out?
In the board there are no shorts, did you want me to yank them out?
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Re: Power Inverter for a Car (Diagnose + Repair)
Also another test, with the driver transistors still on the board, remove the IRF640's and turn the unit on. Make sure the HV DC bus is on, and measure the voltage from the gate pad (where each IRF640 mosfet gate pin was) to ground.Muh-soggy-kneeComment
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Re: Power Inverter for a Car (Diagnose + Repair)
Q7,Q16 the outer ones are NPN KSP42
Q12,Q24 the inner ones are NPN PN222A
I built a transistor testing station i found here, (the third or fourth one down from the top)
http://www.kpsec.freeuk.com/components/tran.htm
I pulled all 4 out and put them in this circuit and all of them acted as an insulator (no LED light) untill I applied voltage to the base, then my LED lit up.Comment
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My cheap crappy 1KW grid tie inverter (GTI) seems to keep blowing IGBTs. When I first got it, it had two failed IGBTs. It used four 60N100's (TO264). I bought 5 from a dubious source (fleabay) and replaced just the two that were dead. The GTI worked for almost two years but recently one of the two that I replaced failed. Since I had three spares, I replaced the dead one. Then a few weeks later it failed again. Weird. Well since I bought dubious China-sourced IGBTs from fleabay it could very well just be a mixture of fakes. I replaced it, but then a day later it failed again! I put in the last...
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I just got this tv today and it appeared to have no backlight on. After taking off the rear cover and checking again in the dark I can see that MAYBE one quadrant is lit.. But still it's quite dim. I was going to check the LEDs with my tester, and I found LED 1 and LED 2 + pins on the wire from the inverter, but I couldn't identify a ground. Nonetheless I tried using a mounting screw on the inverter board and also the chassis as ground but regardless my tester reads 300 which is what it reads when there is no voltage draw.
I don't know how exactly to test the inverter itself. Is it... -
I have a tripp-lite aspint 3636vr inverter charger which blow some of mosfet transistors. I replaced them repaired also the driver circuit and tested but the mosfets burn again.
It work very well as inverter and also as charger if I let the rear switch in auto mode (inverter) and charger only(charging) but in auto when I connect the feed line 220V AC first time it pass ok to line and start charging the batteries but when I remove the feed line it pass to inverter mode and if I do it again the second time when passing from charging to inverter the Main transformer start making a...03-06-2023, 07:07 AM -
For some reason I'm just not going to let this 19" TV defeat me. I guess because I have a schematic to work from I feel like I'm oh so close.
History- while adding a turn-on circuit I let a small screw roll under the power board. Worked through all of that circuitry, probably replacing a MOSFET and PWM controller that were not bad but I was following the service manual. Finally figured out that the power supply is in working order when the inverter section (for the backlights) is disconnected. When the +12 supply to the inverter is disconnected the +12 and +5 will come up... -
If I had a solar fed grid tie inverter (GTI), a modified sine wave inverter, and a power outage occurred, what would happen if you disconnected mains, backfed the modified sinewave inverter (MSI) into house power, and hooked up the GTI to the output of the MSI, would it work?
Next thing is trying to charge the batteries using solar power, but that's another issue ...
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