MEP-831A Battery Charger

[kloppk]

Anyone have a defective MEP-831A battery charger available?
I need one I can partly disassemble to do some reverse engineering.
I'd pay for shipping.
If it's fixable I'll repair it and return it to you.
(Posting here instead of classifieds since no one would likely look in the parts wanted section to sell a defective one)

 

[Demoh]

Ill test the 2 that are untested. I know I have 2 different styles.

If nobody has a bad one you could borrow one.

 

[kloppk]

Looks like there are the rounded corner version and a square corner version.
I have a good one I'm working with now. I don't want to do any further dis-assembly of it and risk damaging it.
Thank you for the offer. I'll hold out for a while and hope to get a defective one.

 

[avenger]

The Battery Charger from my mep 831a Burn down an kill a Resistor.
Has got somebody the electrical resistance value.

 

[kloppk]

That part is a 0.01 ohm 2 watt 1% resistor made by Ohmite. It's the current sense resistor in the charger.
Part number 12FR010E. Can be purchased from several electronic supply houses for ~$3.15 US
https://www.digikey.com/product-detail/en/ohmite/12FR010E/12FR010E-ND/822889
https://www.mouser.com/ProductDetail/Ohmite/12FR010E?qs=xI6jRGneEnB8KXlAgk8WIw==
https://www.newark.com/ohmite/12fr010e/current-sense-resistor-0-01-ohm/dp/64K7857?CMP=AFC-ECIA

If that resistor smoked there may be other damage to the charger.
It's possible the contacts in the relay have welded together and won't open which would cause your battery to discharge when the set isn't running.

 

[dav5]

It looks like it is toast. I bet Kurt would love to get his hands on it to reverse engineer it!!!

 

[avenger]

Thank`s for the fast Help.
I change the resistor and the tree elkos and now it works !!!
Gruß aus West Germany Felix

 

[kloppk]

Excellent! Thank you for getting back and letting everyone know.

For those reading:
elkos = electrolytic capacitor
Gruß = greetings or salutations

 

[kloppk]

Update....
I received a charger from a S.S. member so that I could complete the reverse engineering.
Done.
Prototype charger using the same parts and circuit as the original works as expected.
Printed Circuit Boards designed and being fabricated now.

My plan is to be able to offer assembled, tested replacement boards to drop into dead MEP-831A battery charger housings.
Will include bridge rectifier, diode and transistor located between the PCB and the metal base of the charger housing.
Will post updates and pictures of the new boards once received and populated.

 

[kloppk]

Project completed.
MEP-831A Battery Charger repair kits and repair service available now.
See ad in the Classifieds in the Parts section.

 

[Light in the Dark]

Yeah, but does it make my teenagers complain any less? Thats where the real value prop is...

 

[Chainbreaker]

Very nice work!!! Great to see someone is making after market parts as good or better than OEM!

 

[Guyfang]

Now when are you going to work on some older stuff............................................................

 

[kloppk]

Now when are you going to work on some older stuff...

Guy,
Presently I only have 831's and an 802 in my possession that I can use to develop products.
If I get my hands on or easy access to other generator models I could tackle some of those items.
Could you PM me a list of replacement PN's that are in high demand?

 

[Guyfang]

I will sit down and think about what would fit that criteria. One of the nice things about the old sets was that the -34 manual normally had test and repair procedures. And the -24P had part numbers. And, its old tech. Simpler.

 

[Chainbreaker]

There are a lot of MEP-002a/-003a's out there in service that NEVER run in 3 phase mode. A modern somewhat plug-n-play module to replace/eliminate the AC distribution box internals (except for retaining the output lugs) with an intelligent controller with DIGITAL gauges and options for autostart, etc. would be a VERY attractive retrofit. If done right it would greatly improve reliability (eliminate failing transformers, problematic reconnection switches, failure prone HZ gauge, Volts gauge, etc. and offer much better utility by using digital technology.

SS member "Rusty Stud" did something similar using a modern commercially off the shelf controller. However, if I recall correctly, the changeover took him a quite a while to work out and he knew what he was doing. In other words, it was not a kit that the average MEP-002a/-003a owner could install by following instructions.

 

[Light in the Dark]

Wish Rusty was still around

 

[Light in the Dark]

I've got an 002 local to you Kurt that has an inop hertz gauge, amongst other issues this series is prone to if you are interested in borrowing it...

 

[Guyfang]

Wish Rusty was still around

Rusty is sick, but not down. Tough old bird.

 

[Light in the Dark]

I thought he was banned... swore I saw that under his name just a few weeks ago.