Battery charging contact ideas for H/H device

Jun 12, 2006 10 Replies

Hello,



I am working on a hand held device containing a rechargeable battery. When not in use, the device will be placed in a charging cradle / holder. Charging current is only a few tens of milliamps. I am looking for a few ideas on how to make the spring loaded connections between the cradle and the device. I have searched through quite a few catalogues but have not seen anything suitable as yet.



Maybe someone has overcome this previously and would care to share their experiences with me? I am open to all ideas.



Andy



Maybe something like the "Pogo" pins used on PCB bed-of-nails testers? Farnell have them. How about an induction coil that doesn't need contacts? Is this for production volume?

A cheap and somewhat crude solution would be two banana plugs sticking up out of the charger box which mates with recessed or low profile banana sockets on the device. That will hold the device securely up in the air too, no "cradle" required. Some force required to sit it down, but serves a dual purpose. Using 2mm banana plugs will save space too.

Dave :)

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look at their battery connectors

Cheers Terry

If you are only looking for a really small current, then why not just ordinary induction, no need for any exposed pins, you dont even need a moulded cradle, just sit the h/h device on a pad and let magentism do the rest ?

Regards Mike * GMC/VL Commodore, Calais VL Turbo FuseRail that wont warp or melt ! * High grade milspec ignition driver electronics now in development * Twin Tyres to suit most sedans, trikes and motorcycle sidecars http://niche.iinet.net.au

Hello Dave and group,

Thanks for the replies so far. I forgot to mention the source for the charger will be DC only (from a vehicle). This may complicate the induction idea somewhat. I haven't looked into this fully but maybe there are dedicated devices to achieve this without too much extra engineering?

At this stage only looking at low volumes. I will investigate the 2mm banana plug idea.

Thanks,

Andy

Another possibility is to have two side contacts (one on each side) that contact through wipers when the unit is put in the cradle. Should be fairly easy to do and self cleaning.

Alan

-- Sell your surplus electronic components at

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Search or browse for that IC, capacitor, crystal or other component you need.

One transistor oscillator and coil - little mtp3055 would be ideal and transmit more than enough power, dont even need a core, air is fine, full bridge in receiver with resistor and a zener would prob suffice.

Think big,

Regards Mike * GMC/VL Commodore, Calais VL Turbo FuseRail that wont warp or melt ! * High grade milspec ignition driver electronics now in development * Twin Tyres to suit most sedans, trikes and motorcycle sidecars http://niche.iinet.net.au

Does it need a cradle - can it possibly be mounted directly into the cig. lighter? Like the removable / low cost hands-free phone jobbies.

The best way is to check out cordless phones.

Basically the base as two horizontal bars that can be depressed down, and the phone has two horizontal bars sticking out of it perpedicular.

You could try looking at some of the bistro food places that have radio pagers for when you food is ready. They seem to be quite innovative. Just stack the pagers in a cradle and they charge up thru the lower ones. They seem to be custom made so that may be a problem. There are several variations and you could try the food at the same time.

John G Wot's Your Real Problem?

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