Harbor Freight Inverter Schematic Diagrams

Discussion in 'Power Electronics' started by N11778, Dec 7, 2015.

  1. N11778

    Thread Starter Member

    Dec 4, 2015
    39
    7
    I have been using several of their inverters for powering small Air Conditioners(6000btu) , Refrigerators, Pool Pumps,etc. from my solar panels. They have been doing well except for the cheep fans they quit and a couple resistors get to hot.
    I have replaced (EBAY "mynewfan") all the fans with ones with ball bearings.
    Also the resistors that get hot with larger wattage ones.
    They have been running for 3 years or more with no problems and they are very Inexpensive.
    I made a control system from a keyence PLC that controls everything so I am not tied to the grid.
    The reason why I drew the Schematics of the Inverters is I blew a few of them up with my automatic controls design.
    I repaired all of them and they still work fine.
    I am attaching the diagrams In case someone else is interested in repairing them.
    Be advised there are mistakes in the diagrams, I found several. Try following a double sided board Yuck!
    But their better than none or a poke with a sharp stick.
     
  2. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Cool
    You don't see many schematics of inverters. All of the inverters I have repaired, I have had to "wing it", as in no schematics.

    Thanks for posting these.
     
  3. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    I don't need these, but I would like to recognize your awesomeness. Thank you for posting this.

    If ever I need a big inverter, I'll choose the one i can get schematics of, which i guess now means harbor freight, thanks to you. HF should compensate you for your advertisement, and for having the good sense that they don't, to publish friggin schematics! Why wouldn't they do that? Is their circuit so special? Is it revolutionary? Would they lose the market by publishing it? NO! Everyone makes inverters. That made in China inverter design was probably ripped off from someone else anyway.

    Well I'll cut the rant short, thanks again!
     
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,006
    3,763
    They probably don't publish it because they ne er had one. They just went to some tradeshow in Hong kong and said, I'll take 10,000 of those if you put this HF logo on it.
     
    DerStrom8 likes this.
  5. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    I have a 1000 watt Xantrex inverter that I burnt up and repaired. Xantrex is a big brand name, but still no schematics available. The electronics industry wants you to "buy new" instead of repairing. Remember the corner TV repair shop, long gone.
     
    Sinus23 and shortbus like this.
  6. N11778

    Thread Starter Member

    Dec 4, 2015
    39
    7
    I have another Inverter Schematic to add.
    An Older but Better 2000W Harbor Freight Item # 69662
     
    strantor likes this.
  7. bwilliams60

    Active Member

    Nov 18, 2012
    722
    88
    What program are you using to draw these? Nice diagrams.
     
  8. N11778

    Thread Starter Member

    Dec 4, 2015
    39
    7
    microsoft Paint Keep in mind there are going to be mistakes. I followed a double sided board.
     
  9. Denesius

    Member

    Feb 5, 2014
    89
    14
    Your perseverance is commendable!
     
  10. MrAl

    Well-Known Member

    Jun 17, 2014
    2,425
    490
    Hi,

    Yes very nice!
    +Like
     
  11. SLK001

    Well-Known Member

    Nov 29, 2011
    812
    225
    Are any of these pure sine wave output, or are they all just modified sine wave?
     
  12. N11778

    Thread Starter Member

    Dec 4, 2015
    39
    7
    They are all modified sine wave.
     
  13. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    Does anyone know the switching frequency of the PWM controller/driver-transformer? Just curious.
     
  14. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    And isn't modified sine wave just a glamorous way to say 3-step square wave? My inverter puts out a square wave but with a brief zero-voltage in between peaks. Hi-zero-low-zero and so on. I'm pretty sure that makes it a modified sine wave.
     
  15. N11778

    Thread Starter Member

    Dec 4, 2015
    39
    7
     
  16. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    Yup.
     
  17. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    I do not have it. As noted in #2, those are usually hard or impossible to find.
     
  18. Joy Smith

    New Member

    Jun 22, 2016
    2
    0
    Thank You soo much! I run 4 of these units for daytime only apps. I like them because they go to sleep then wake up with the sun. Most don't. Obviously the time bomb is R50, R118 and R119. I kept some going for years by just cutting a big hole in the top cover and installing a 4" 12V fan hooked to it's own small PV panel. Yes, the fans suck,and I had the fan controller go out on one. When the resistors burn you can't read them, so I am very grateful to get the values from you. I have several units in the scrap pile I will go back to and try to repair this winter. We are a solar dairy so summer is busy. Is there anything else that dies when these resistors go? I'm guessing not. Yes, I have been too lazy to open a new one to read those resistors!
     
  19. Joy Smith

    New Member

    Jun 22, 2016
    2
    0
    I wonder what parts you might recommend I keep on hand for these inverters.
     
  20. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
    1,143
    202
    Awesome.

    If you like doing these I have some single sided boards you can do for me. I'll pay. I do have a parts list, but not electronic at this point. Possibly some mirrored pics that I could get scanned. Physical parts not required.

    Thanks.
     
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