I wonder what parts you might recommend I keep on hand for these inverters.

If you have the older inverter (three fans on the rear) in the scrap pile do not let them get away.
I have not needed one of the U16C40A yet. They cross to a FEP16JTA which is now Obsolete.
I can find nothing to replace it with. If you find something to replace it with post it if you would please.
I found most of the other stuff. If you need the EM78P176ND 18 J (PLC chip you can't program it
anyway) use the rest for spare parts. Send me the U16C40A rectifier chips

 

Do an enquiry here: http://www.littlediode.com/components/search.php?mod A nice company to deal with.

 

I have open R50 and R118 Resistors, sounds like it might be a good idea to increase the wattage. Thanks for the info...

 

Is there a specific type, size or better yet, part number for the replacement of the R50 and R118 (to the .5 W) resistors?
I'm not finding any that are the size of the originals...They are about 3/8 inch long, 1/8 in width. Dark brown in color,
or at least they are now! 5 band color code...
Thanks in advance

 

Is there a specific type, size or better yet, part number for the replacement of the R50 and R118 (to the .5 W) resistors?
I'm not finding any that are the size of the originals...They are about 3/8 inch long, 1/8 in width. Dark brown in color,
or at least they are now! 5 band color code...
Thanks in advance

I don't know what you're asking for. If you know the Ohms values, they should be easy to find at Mouser or any other supplier. If you don't know the ohms values, there's nothing we can do.

 

I don't know what you're asking for. If you know the Ohms values, they should be easy to find at Mouser or any other supplier. If you don't know the ohms values, there's nothing we can do.

Sorry I was hoping N11778 might be able to provide the correct upgraded resistor values. They are 10k and 15k, with 143.5 vdc supplied to them. If I'm not mistaken, that would be 1.36w for the 15k, and 2.04 for the 10k.
Thanks to the online ohms law calculator... They have burned out at the original wattage rating, which is still unknown to me. According to my research, the resistor would normally have two to three times the normal wattage range expected at the resistor designed into the circuit. Assuming this to be true of this circuit, I'm thinking that the original resistors are probably resistor 5W to 6W resistors? Perhaps a photo will help...Of course the brown ones that are out of circuit are the ones I need to replace, and would like to increase the wattage from the originals... Any suggestions?

 

I replaced the 10k with a 7watt and the 15k with a 5 watt.
none of mine failed I replaced them when I changed the fans because they were black already.
I put the resistors on the foil side of the board they are to big to fit on the component side.
I replaced them in 7 Inverters and they are still working ok as I type this. Knock on wood desk.
there is room on the foil side if you keep them fairly close to the board.

http://www.ebay.com/itm/25-pcs-15K-...242?pt=LH_DefaultDomain_0&hash=item1c37c5638a
http://www.ebay.com/itm/25-pcs-15K-...242?pt=LH_DefaultDomain_0&hash=item1c37c5638a
http://www.ebay.com/itm/QTY-10-10K-...036?pt=LH_DefaultDomain_0&hash=item19e470efac

 

I replaced the 10k with a 7watt and the 15k with a 5 watt.
none of mine failed I replaced them when I changed the fans because they were black already.
I put the resistors on the foil side of the board they are to big to fit on the component side.
I replaced them in 7 Inverters and they are still working ok as I type this. Knock on wood desk.
there is room on the foil side if you keep them fairly close to the board.

http://www.ebay.com/itm/25-pcs-15K-...242?pt=LH_DefaultDomain_0&hash=item1c37c5638a
http://www.ebay.com/itm/QTY-10-10K-...036?pt=LH_DefaultDomain_0&hash=item19e470efac

 

Thanks a bunch 'N'. Very much appreciate the reply. I'm trying to save a Christmas
gift from last year, I only got about 3 months use out of the inverter before it failed. It
took about 3 months before I installed it, so it was well out of warranty.
I can imagine the resistors might actually run a little cooler on the foil side too...closer
to the heat sink/cover, and further from other components.

Thanks again!

 

Hmmm, I did replace the open resistors, and the inverter did work afterward on a small load (a light bulb). But under
higher load, it cycles on and off repeatedly at about 2 second intervals. I removed and tested all 8 of the mosfets, they all check good using a
transister tester. Any ideas from here??

 

Can you detect heat being generated in one spot? If you suspect a part, they sell canned coolant you can spray on that part to keep it colder longer. You might be able to diagnose where the problem is.

 

Hmmm, I did replace the open resistors, and the inverter did work afterward on a small load (a light bulb). But under
higher load, it cycles on and off repeatedly at about 2 second intervals. I removed and tested all 8 of the mosfets, they all check good using a
transister tester. Any ideas from here??

Sounds Like you mite be using a battery that is to Small or the voltage is already low.
Try two light bulbs then three etc. and watch the battery voltage.The inverter shuts down at aprox 11 volts.
It's built in to protect the battery from going to low and back charging a cell.
when the voltage goes low the inverter shuts off then the battery voltage climbs back up and the inverter restarts.
100 watt load is about 10 amps from the battery. the battery current goes up fast.
2000 watts is about 200amps from the battery. Good golf cart batteries are about 200 amp hours.
you also have to use large enough wire to handle the amps from the battery number 6 or 4 wire is the smallest
you should use for big loads.
sounds like the inverter is OK.

 

Mine were blown, this helps, thank you.

 

Can somebody tell me what is the 10K and the 15K, labeled 1 and 2 in photo, so can replace mine. The color is so faint I can't read them.

 

I figured it out. r118=10k. r50=15k