parallax 7300 converter

[quaddriver]

I have torn into the blown unit from my stepdads View, sourced some power and started probing....I really could use a SCM which no one says they have, but does anyone have operational info on these PPS converters?

what does work is the AC filter system, and a rectifier/doubler that outputs 170VDC!~~ 170!!! that is 'burn off your flesh painfully' territory.

Im guessing, but they produce high VDC, invert it at a higher frequency, then rectify it, and then filter out both sides of the transformer with chokes?

there is also no provision for a battery cutout to isolate the battery and charge it, in fact the manual states full output can be used to charge the battery. burn the battery out?

are there known issues with these burning out batteries? the stepdads batteries were zorched, which in turn I think took down the converter.

anyone know the values of R67-74? they got so hot the colors are burned off....they are 1w resistors, was gonna replace with 2w or better

[quaddriver]

S-U-C-C-E-S-S

they were 2w, and I found 5w online. I measured the resistance in the circuit of all 5 of 67-71 (the others ok) and found 36.6ohm. working backwards using ohms law and algebra, that works out to 180ohms.

So I call PPS and talk to 'Marty Rhett' ask him the value of R67-71 he comes back with 180ohm, 2w, 5%. Am I good or what.

Apparently, the dog killed it. water dish was nearby, it got spilled, was covered in fur from where he laid for the last year and a half, wet fur on output, ran over, popped the 10A fuse leading to the inverter section. ITs soldered to the board, so I have a ACG fuse holder, a soldering gun, some fuses, gonna make it a user servicable item.

Since I was dealing with LOTS of DC, I tested this thing using the old rheostat trick.

Now who here has a bad 73xx series? Send em in...

PPS wont release the schematic or give much help other than identifying parts, but I got this pretty well traced out.

Since I am no longer using the battery charge section of the 6330 in the winnie, when I pop this in, the 6330 will be available...any interest?

[JohnB]

Quad

Good you got it sorted out. Those electronic skills come in handy. If they would give a true electronic schematic of these RV things it would make it a bit easier to trouble shoot. However I too have board traced and created my one from time to time. It works, just takes longer.

John