PowerBright Pure Sine Inverters Part3 - Repairing the 2200 Watt Inverter continued...
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- čas přidán 29. 08. 2024
- In this series I cover my experience(s) with two PowerBright Pure Sine inverters including unboxing, disassembling, repair, and testing.
Another good video! I really liked the fact that you spent some time going over the stages and some basic this is how this works type stuff. Hopefully you can get a free sample to get it up and working.
When mounting transistor pairs with one mounting screw in the middle, I recommend putting a thin bead of solder on the rocker clamp, right over the dice of the transistors. You don't want the clamp to touch the edge of the transistors near the screw, because it tends to roll the transistor bodies inwards, and off the pads. If you can shim the very centers of the transistor bodies, so the force is applied to the center of the body, you will get much better heat transfer from the device to the heat sink. I think that's what happened to the 2,200 watt inverter. If you read the specs on the transistors, they're more than adequate for the extra current. another advantage of using rocker clamps with spacers over the device bodies, is that they act something like a spring, maintaining pressure on the devices, as the insulators become thinner, and, it compensates for thermal expansion. Anything is better than using screws and shoulder washers through the mounting holes, especially on the smaller TO-220 devices. On the larger TO-247 devices, the mounting hole works pretty well, because it's more in the center of the foot print, and, the larger pad area transfers heat better anyway.
I quit having problems with my amplifiers when I went from screw hole mounting to rocker clamping, because of the less-than-perfect extruded heat sink surfaces.
TL594C. I ended up buying a couple of them so I still have one extra. Thanks for offering!
I've used those thin alligator leads and they themselves make a nice fuse when need be :D Have saved my projects on more than one occasion. Nowadays I use a decent lab power supply for any kind of repair work. Not nearly as fun as those alligator leads :)
You mean the flexible extendable slow blow fuses with visible smoke indication?🤣😝😁
no problem, just didn't know how hard it was gonna be to get a hold of them cause like you said most places don't let you get onesies and what not but good luck in getting that one to work, guess you you got lucky on the other one though, seems to work decently, even after the heatsink mishap.
GREAT VIDEO very educational.. thanks, thumbs up....
That chip quick stuff looks pretty nifty, I might have to give it a try. I admit that I do not really have the proper equipment on hand to be doing this stuff efficiently.
its a trap!
Good video,
That looks like a TL-494, would be a good idea to get an 100 MHZ > oscilloscope else, you flying blind (you need to determine the shape of the waves ect..) another thing, PLEASE always use a heat-sink,internally good switching circuits OR high power ones, always has a dummy-load internally about 1 watt or so, (with RF snubbing) enough to heat/warm all the MOSFETS to death without a heat-sink.
Anyway, I suspect one weakness is the mosfet drive current to the gates, it seems insufficient at first glance, that IC only supplies 200mA per buffer phase of the TWO phases when configured in push-pull mode which is the case here, you can easily calculate the required MOSFET drive gate charge by adding up all capacitance of all the gates (found in the datasheet) and check the "drive frequency", IR has some good papers around this.
The PNP stages are used as a fast turn off, this is used to pull the FET to ground, basically discharge the mosfets gate by the time the second phase is on the first phase is "guaranteed" to be off, protecting the FETS from "shot through".Good switching power supplies use efficient gate drive IC schemes IR2113 OR 2110 (some clever engineers use desecrate BJT methods) to perform efficient gate driving (and maybe coupled with a final totem pole BJT if gate current requirements increases)
(Anyway, get a scope I would like to see more videos with "live probing" the output waves tells alot about the inverter never mind the way it looks.
Cheers ;)
I'd love to have a scope for this sort of work, but a decent very basic DSO is around a thousand dollars and I've found ways to get around needing one from experience working with circuitry and scopes. I haven't gotten 'burned' yet with educated guessing on these (often poorly designed) inverters, but someday if I find a good deal on a scope I may be able to show more.
***** You can get a rigol ds1052e for about 329 dollars (new) OR DS2102 (series 2000) for 1,200 dollar (if you want advance features) at a cost of course.
I own a SIGLENT SDS 1102CML 100Mhz I paid 350 dollars for it (new) it works fine.
Yes, a variable power supply would be nice for this type of project. Too bad the only reasonably priced ones I've found are Chinese junk. I should probably just get one anyway though since they're better than nothing. I think..
If you do get one, take it apart, and check to see that the power transistors are properly mounted to the heat sink. Typically, the design is pretty good, it's just the workmanship you need to be aware of. You may see the same mounting problem you saw in these inverters, and it's also something I check in cheap car audio amplifiers.
miss my scope 514 d tecktronix big 5^ crt aah single trace but all tube some glass some metal
I have a go power 3000w having a little problems. I have replaced few capacitors and all 5 main fuse board have blown and replaced but my fuse keep blowing. Do you have any ideas whats goin on? Or where i need to check first??? Thanks
Mosfets dont work with current like bjt it works with voltage
I have a similar faulty inverter that goes to overload when power without any load connected. Do you have any video on how to repair the fault?. Thanks
I also have an inveter almost the same .. HQ pure2kw-24 and also my overloaded marker without load attached
hay dude, you wana build a generator inverter pss .that dosent need gas. something to run a house with and barely much cost inverters are a help but need a cheaper way to charge the batterys well enough aganst the drain. or power off till charged .ide like to build something that gives a few choices of power source also for different locations.
whats the part number on it? I have a ton of TI SMD components and I may have one if im lucky.
hi, do you have the scheme of this inverter? could you send it to me?
where did you buy your miniscope???
eBay about 10 years ago. It is now obsolete but still works well for this sort of thing.
is that limited edition?
dj minions de spicable
It was a standard Craftsman product at the time. I'm not sure why finding a scopemeter is so difficult today. Technology has progressed to the point where it would literally only cost an extra $20 or so to put it into a meter but, well, I guess the demand just isn't there.
***** that sucks. i been keeping an eye out for a multimeter like yours with the scope. i'm just in love with it. my meter dun have one. and while i know it may not be as good as a major oscilloscope, i would be happy with one like yours for the portability. this is all i got. its ok i guess. lol tinyurl.com/m6gmrfa
need parts allied electronics digi key mouser just to mention a few, need more yell ,i did tv shop 30yrs some ham cb good deal of everything allways willing to help other techs novice i allso build. tubes to chip . audio is my specialty . unfortunately in new york i cant get the work i used to see and do on repairs, i still do works but ppl are into much, cell pc lap ipod tablet its soo stupid thay dont even know what cb radio is, people in public used to have hobbies things to build to learn how to create now its like there just robots, wtf sorry dude ,its just retarted to see know.
The throwaway nature of products today and people's complete disinterest in knowing the basics about the products they use and rely on bothers me too. I guess everything is so complicated anymore it's just not worth the effort to know how it works.
*****
I totally agree with You. Consumers (in general) just have no interest whatsoever regarding the stuff they throw their hard earned money at. People looking for the best-bang-for-a-buck products are scarce. Manufacturers, of cource, act accordingly and they are absolutely not to blame. I would do the same in their position. That's why I've made a habit of hunting down and refurbishing "old rubbish". Yeah, right...those over engineered and thought out quality products are definitely junk compared to modern consumer level electronics. Makes my head hurt thinking about it...