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Using less than 12 dollars worth of parts, get more power / fix your broken power inverter
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Signing UpStep 1Diagnosing the problem
This instructable is a guide for repairing/increasing the output power of a simple dc-AC power converter (this instructable address the boost dc-dc converter based power inverter). For the record, a power inverter converts ~ 12V dc--> ~120 AC (normally non-sinusoidal). to increase the power output, the amount of output current the device can source is increased, whereas its output voltage remains the same.
Below is an MS Paint rendition of the first stage of a boot dc-dc. the boost stage amplifies the current from a lower voltage to a higher voltage, all in a DC environment. Read about dc-dc inverters on wikipedia.dc-dc converter (boost)
The boost topology can be made smaller and lighter than huge transformer systems, like an APC or UPS power supply.
At the heart of this system is two N channel MOSFETS. (your inverters configuration could have anywhere from 1 to 4 based upon design)
For those who dont know what a mosfet is, its simple enough to say its a kinda like a really fast switch.
The characteristics of this switch are what determines how much current the dc side of the device can source.
Below is an MS Paint rendition of the first stage of a boot dc-dc. the boost stage amplifies the current from a lower voltage to a higher voltage, all in a DC environment. Read about dc-dc inverters on wikipedia.dc-dc converter (boost)
The boost topology can be made smaller and lighter than huge transformer systems, like an APC or UPS power supply.
At the heart of this system is two N channel MOSFETS. (your inverters configuration could have anywhere from 1 to 4 based upon design)
For those who dont know what a mosfet is, its simple enough to say its a kinda like a really fast switch.
The characteristics of this switch are what determines how much current the dc side of the device can source.
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I have a WAGAN Slimline 1500 watt Inverter. I ran the output through the breaker box in the house, which is grounded. I used my car to run the system, but had another, larger battery in parallel with the car battery. The unit ran everything in the house. Microwave, fridge, lights and TVs. Had the unit going for about eight hours, then decided to give it a break and turned it off. I then experienced a very dramatic fireworks / light / smoke show. I was most upset. I know enough about electronics to figure that the inverter was toast.
I put it down and forgot about it. Two years later I broke out the electronics gear and decided that I would try and fix it (the fact that another storm had passed through leaving us without light again probably had something to o with it!) I found that the MOSFET's on one side of the circuit board, all eight of them, were completely gutted. Talk about your catastrophic faliure. The MOSFETS are Fairchild FDP8770 N-Channel. There are eight other MOSFET's on the opposite side of the board, LVP640's (N Channel also). They look fine. The fans were working at the time of the fireworks.
My questions are:
1) Why did it blow up when the unit was being turned off?
2) If I start the car with the Inverter connected will it do any harm to it, and why?
3) I see three pots on the board, and am decent with a soldering iron. I want to fix it myself. Assuming I can get the parts I think it needs, Do I need to match the MOSFETs, which would mean I might have to throw away some good looking LVP640's, and how do I go about doing this?
The board is set up with four transformers, and each is in series with a fuse. None of the fuses blew. I know that I'm kinda above my head in this, but I wanna try. Thanks for any help I can get!
2)The starter motor of a car draws LARGE amounts of currents from the battery ( read 150 Amps) and placing do much load on the battery (inverter +car) will probably cause fireworks
3) I do not get the three pots thingy but if you wish to fix it you should replace all the blown components with new ones!
Best of luck :)
i am a new person here,can somebody help me explain how these modern inverters work without large transformers please?.
store.thesolarbiz.com/online/Items.aspx?code=SMA_GRID_TIED&key=cat
1.are you getting anything from the inverter, like does a cell phone charger, or something small work?
2. what are the exact lights that come on, it looks like there is a 10 bar led display on the front. when you plug it in with no load, what does it say?
3. whats the ethernet port for? (oh its for some kinda remote starter, nevermind)
4. is it doing any thing specific and sequential, like blinking red once ever 2 seconds or some weird pattern?
i looked online for a manual and found it at:
www.donrowe.com/user_guides/vector/vector_d_models.pdfwww.donrowe.com/user_guides/vector/vector_d_models.pdf
oh, is your laptop supposed to take in 50HZ or 60HZ. it appears the inverter is 120 AC, 60HZ. look on the back of your power supply for 50 or 60HZ. is it says both your in the clear. if it says 50 and your inverter does 60, you would have to modify the inverter.
best of luck, send a message back to this list for anything else. send a pic of your solar house if you can, sounds awesome
-Dane
this hack might be more useful for repairing an inverter, the power gain is on the order of 5 to 10 watts. its limited by the inverter's main inductor after that point.
unfortunately i didn't load cell test the device at the time (a year ago), so no numbers accompany the test. it was however more responsive to inductive loads (motors) after the modification than before.
-if i get a chance to test it i will post any increases. you bring up a good point.