Battery charger repair?

rplarry · September 2006

I have a Todd engineering PC75b Power Source battery charger that needs repair. I understand that Todd has gone out of business and was hoping that someone on this forum might know of a place that can repair these chargers. It is very similar looking to the Iota chargers but the last time I checked Iota would not repair the Todd charger. Any ideas?
Thanks,
Larry

niel · September 2006

Re: Battery charger repair?

that could be a tough one to answer. even if you find somebody to fix it, parts may not be available for it. i know myself and a few others on the forum if we had it in front of us may be able to determine the source of the problem with it. this could be a bad transformer(can be expensive if available) or something as simple as an internal fuse. from your location makes this even tougher as there's nothing close so you could windup shipping it without knowing if it is repairable at all due primarilly to parts availabilities. i'd say if you have no luck finding somebody definite then look inside for something like a fuse or a loose wire that may be fixable by you or get another charger.

rplarry · September 2006

Re: Battery charger repair?

Thanks Niel
I did open it up and found burnt component on the mother board, not sure what the component was but I did find a place in Virginia that says they can fix it. I'll let you know how it ends up.
Larry
PS I'm at my summer place in San Diego right now, way too hot in Bahia in July, August, and most of September. Of course the fishing is really good down there at that time.

niel · September 2006

Re: Battery charger repair?

ah very good then and i wish you luck on the repair. odds are the component is a burnt resistor, but it could easily be something else too.

BB. · September 2006

Re: Battery charger repair?

Make sure that you:

1) get a firm quote from the guy doing the repair--and/or give him a price not to exceed. Also, have him tell you exactly what the part was replaced with--and if he knows what the part did in the circuit. It is possible that a) the part was too small (like an 1/8 watt resistor getting a 1/4 watt of power driven through it--so it will happen again unless a heavier component is used), or b) that something else shorted while you where working around the area (like shorting a sense lead or something).

And

2) before you send in the unit, look for heat/burned areas elsewhere on the board. On some designs, the designer runs many parts too hot (or there was poor cooling where the device was installed) and it is just time before one or more other components fails--and even the first repair is just a lost cause.

I google'd around and found a comment from somebody else that had the same (or similar) charger and he too reported a burnt resistor that he had replaced by a TV repair guy and all was well again.

-Bill

rplarry · September 2006

Re: Battery charger repair?

I contacted the place in Virginia and they do not mess with these things any more. Since I had nothing else to do yesterday I decided to try to repair it myself. I opened it up and found a blown FET a burnt resistor and a broken trace on the PCB. I took the board up to the local surplus electronics place and they were able to match the parts and I was able to solder the broken trace. After all was said and done I put it back together and plugged it in. No smoke but one of the large capacitors makes a loud pop, so I unplugged it and put it back on the shelf. Maybe someday I will find someone with ability to repair it that has nothing better to do. So much for my electronics abilities.
Larry

niel · September 2006

Re: Battery charger repair?

a cracked pcb is serious. did it get thrown out the window or something? recheck the board traces with a magnifying glass. no more opens from the cracked pcb or shorts from your soldering job. as to the cap it can be replaced too, but a determination of the type of cap and its values is needed to be known. go to radioshack.com to see the general look of it, but do be aware that some types have a polarity and if you remove the old cap make a note of which part of the cap was soldered where just in case. you went this far so keep going, but slowly if you're unsure.

System2 · October 2008

Re: Battery charger repair in Kabul

Greetings folks from Kabul. I am totally new here, but after an hour or so Googling, could only come up with this forum where I thought I might an answer.
I live in Kabul, Afghanistan (work with an aid agency). Given no electricty, we use solar set-ups. I inherited a Todd PC 45 battery charger from a colleague. We have city electricity once a week or so, and tonight was using the Todd to give our four worn out old batteries a charge.
Our power then failed at the meter box. I replaced the fuse, and when I came back the Todd had fused the power socket it was plugged into. After a bit of testing, it turns out the active and neutral wires inside it are linked, ie, on the multimeter, they give a beep. Any time I plug it in, it fuses immediately.
So - I have no real idea where to go. Can't see any burns inside the case, no bad burnt smell. the charger was working fine at a friends house charging his system. It was plugged into an unregulated 200-240/250 AC V supply; it was still plugged in when I replaced the meter box fuse.
- could that have created a power surge?
- can these Todd work fine with 240V? it has a US style plug on it... but it had been working fine for a week on 240V
- are there schematics I can fine somewhere?
- could it be an internal fuse? where could I find such a fuse?
Any help gratefully accepted. We dont have local repair shops here in Kabul.
Thanks,
Phil

BB. · October 2008

Re: Battery charger repair?

A person on another forum posted a PDF schematic for a PC 45 (or PC30)...

It appears that your unit may be a 120 VAC unit only... The fact that it worked for awhile on 220 VAC 50Hz (?) system is probably just luck... Many times, people would bring a small 220/120 VAC transformer to connect 120 VAC North American product... It is possible that the previous owner used such a transformer (60Hz vs 50Hz could also cause some issues).

If there is a local "TV Repair" shop--they can probably find a blown cap or rectifier bridge to fix it...

Measuring resistance with a meter may be a bit difficult--depending on the kind of meter, and voltage/test range it is set too...

You could take a small light bulb (night light or small filament desk lamp) and wire it in series with the power plug and start measuring and disconnecting caps and rectifiers until you find the short...

And yes, something shorting internally could pop your fuses.

Is there anything like a input power rating label? Also, if this was a dual voltage unit, there probably would be a 120/220 VAC switch (or jumper inside). Looking at the schematics, this is probably not a company/product model line that had auto switching 120/220 VAC.

I know you are a fair distance from Costco/Walmart--but it may be time to see if you can locate a replacement (should be over 10 years old by now).

-Bill

mike95490 · October 2008

Re: Battery charger repair?

With the schematic, and maybe a sympathetic HAM radio operator, you should be able to trouble shoot it.

niel · October 2008

Re: Battery charger repair?

you might consider asking one of the soldiers with a radio if he could help you with your problem or at least direct you to somebody who could.

System2 · October 2008

Re: Battery charger repair?

Thanks very much for the replies.
- the input specs were listed on the top cover, but tantalisingly, all that is now left is '..NPUT' and below that a V for the voltage input. The other letters have rubbed off over time. I'm guessing though it is a 110V model, and like you said Bill, I was just lucky. Probably when I replaced the fuse in the meter box (which I had to do with an old bolt, no fuses available...) there was a spike and that pushed it over the edge.
- I've got the schematic now (thanks Bill). (not that it means alot to me, but I'll get a colleague to look at it).
- given that the PC 45 is a 45 Amp model, and if it is a 110V model, wouldn't it require a quite a powerful transformer for me to run at 220V?
Thanks again.
Cold in Kabul,
Phil.

niel · October 2008

Re: Battery charger repair?

it would need to handle a good bit of power. minimumly it would need to handle the charger's power of 45a x 15v = 630w. losses and efficiencies taken into account along with a margin for error for the charger's power requirements could place this at 750w or more. in doing a search and looking at the first on the search list shows the appropriate transformer types and some of their pricing.
http://www.voltage-converter-transformers.com/step-down-transformer.html
the 1000w model isn't much more in cost than the 750w model and may be worth getting, if not for your present charger then for any in the future that would require this transformation.

System2 · October 2008

Re: Battery charger repair?

Thanks a lot Niel, really appreciate it. Getting information here is difficult, and we are all presently under lock down after the shooting of the aid worker last week. So I am grateful.
I'll see if we can get it repaired, and then buy a 1500W stabiliser/ transformer. There are good reliable ones available here.
Phil

Battery charger repair?

Comments

Categories