Wet plugs for charging

[Packhorse]

Got a MB SUB halogen 50watt hand held on my bench for repair/conversion at present.

Have not seen one before but what I find interesting is that it has wet plugs for charging. These lead into the unit and go directly to a bridge rectifier ( even though the charger is DC).

The result is that you can connect the charging leads to any wet plug and there is not feed back of current from the battery when the light is submerged.

I had though of this before but wasnt 100% sure if it would work.

If its good enough for MB SUB then its good enough for me!
Cant see an OPV in the light though so I am unsure what happens if the NiMh cells off gas when being charged.

 

[cummings66]

I've seen this in some of the electronics I repair at work and it's an ingenious solution to users who can't be trusted to plug things in correctly. I like it a lot, but there is a voltage drop of course due to the rectifier and you'd need to take that into account.

Also, some smart chargers don't like a diode in the circuit because it gives them a false reading and they won't work. In my RC planes I've had to bypass the diode in my transmitter because my Alpha IV wouldn't charge it otherwise. It's a smart charger and it could sense the battery condition and the diode interfered with that, so no charging.

Still, I'd bet the gas vented wouldn't be a big problem, other than they claim if you vent from a battery there will be a reduction in battery performance up to and including it's spilling it's guts out depending on how bad it was.

 

[sharkbite]

Always thought this would be a good idea, and will now give it a try...

Although my idea was a single diode - not a rectifier.... (you'd have to wire it up the right way to charge, but would result in only half the voltage drop)

You could put the charging cct inside the canister as well.....and design it so that it can only charge slowly....
limiting the chances (or at least minimising the effects )of a gas-off....

i'd pot the whole charging cct in epoxy as well...

my thoughts would be to have two SS bolts sticking out rather than a connector - so you could use
a standard 12v battery charger (and its associated alligator clips) to supply the current....

this and a magnetic switch would mean only one hole (cable gland) that the canister can leak through....

 

[Stephane_A]

Hi,

You can build your own rectifier with power schottky diodes which have a low drop-out voltage.
But I don't know how the charger will react with the diodes: will the delta V detection be sufficient?



--
Stéphane Acounis

 

[josb]

Question,

Does anyone have a wiring diagram on how to connect things like this?

 

[DIWdiver]

Take two diodes and tie the cathodes (marked with a band or bar) together. That's your '+' output.

Take the other two diodes and connect the anodes together. That's your '-' output.

Tie each of the loose anodes to one of the loose cathodes. These are your 'AC' inputs. You should end up with four diodes tied in a ring. It doesn't matter which way you connect the input, the output will always come out as stated above.

 

[sharkbite]

!!!!!


http://en.wikipedia.org/wiki/Diode_bridge


!!!!!