Napa 12V/6V battery charger

[RJARRRPCGP]

Today, where I was at for a cookout, I encountered a battery charger that had red wires on the inside of the housing fried.

But, check this out, it actually looked like it had connectors in the wrong places.

[budm]

Re: Napa 12V/6V battery charger

I do not get your drawing, where is the rectifier? and what are those straight thick black lines?
May be good clear pictures of the unit?

[RJARRRPCGP]

Re: Napa 12V/6V battery charger

I do not get your drawing, where is the rectifier? and what are those straight thick black lines?
May be good clear pictures of the unit?

Darn it! I didn't have my camera...

For some reason I couldn't see the bridge rectifier and I believe there's zero filtering caps for the DC output! (AC hum heard in starter when powering up the starter of a riding lawn mower engine)

And the charging mode dial appears to just change which windings to connect to on the transformer. The transformer is large.

Where I said WTF is where I saw a connector blade of a red wire touch one for a black wire and thus appeared to connect with something unrelated.

[stj]

Re: Napa 12V/6V battery charger

i'v seen a lot of old car battery chargers that only used a rectifier & fuse - no caps.
the battery is a giant cap - so i suppose if there is no electronics to drive then they dont care.

[japlytic]

Re: Napa 12V/6V battery charger

i'v seen a lot of old car battery chargers that only used a rectifier & fuse - no caps.
the battery is a giant cap - so i suppose if there is no electronics to drive then they dont care.

Such chargers are pulse chargers which deliver its maximum current peak at the highest positive and negative peaks of the AC waveform, which helps prevent the battery from gaseous reactions.

[budm]

Re: Napa 12V/6V battery charger

Such chargers are pulse chargers which deliver its maximum current peak at the highest positive and negative peaks of the AC waveform, which helps prevent the battery from gaseous reactions.

+1, Full wave bridge will give 120Hz charging pulse, no filter cap needed.

[eccerr0r]

Re: Napa 12V/6V battery charger

My guess at the drawing is that the charger is a multi-winding primary, center tapped, multiple parallel output secondary. There is a 2-diode fullwave bridge depicted as a twig at the top of the "transformer" box...

But yes better picture needed :-p This was only a guess...

Then again this is atypical. There is usually a bit of regulation but that's definitely not clear from the picture...