Multi channel battery charger

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Multi Channel Battery Charger

aka the "SuperCharger"

See Product News for product availability.

Multi-Battery (Gang)Charger

Specifications and Features

• 15 batteries per unit.
• Charge batteries in 2 hours
• AC (120/240V) and DC operation
• Operates at 50 degrees Centigrade ambient temperature
• External laptop power DC cables.
  • 2 of the XO DC power cables available to the kids so they they can power their laptops while they switch batteries. This keeps them from having to turn off the laptops to switch batteries.
• Bi-Color indicator LED per battery channel
  • Red Led and Green Led. Same color setup as the XO laptop. Red, Green, and Yellow when both are enabled.

Future

• RJ45 10/100 ethernet connection

Electrical Input Requirements

• AC Power 100V-230V. 300W
• DC 10V-28V. 150W

Exterior Connections

• AC In: IEC for 120/220VAC
• DC In: 10VDC to 28VDC 2 Pin connector that mates with whats on the GP solar blanket.
• USB B connector (Its a USB device)
• 2 cables with XO DC jacks on them

Electrical Misc

• The CPU is an Atmel At91SAM7x family part.
  • See http://www.atmel.com/dyn/products/product_card.asp?part_id=3754
• The per battery DC-DC charger is a SEPIC design based around a MicroChip MCP1631 part

Software

• Forth/C combination.
• http://dev.laptop.org/git?p=projects/supercharger;a=summary

Mechanical

• Density. Getting as many batteries as possible in as small a footprint is a goal.

• Physical Safety. Its got to be stable and hold lots of heavy batteries but not be able to fall over on top of a child. Who might be trying to climb on it to get his battery.

• Stackable. More vertical space is available than floor sq footage so an idea was to make them stackable. But see above point.

• Heat dissipation. Each power supply stage is about 85% and there are 2 stages for a total efficiency of 72% So while on DC heat dissipation will be around 58 Watts and on AC around 88 Watts.

• Enclosure. Metal. Except perhaps for some plastic for the battery holder. Having metal available to heatsink to should help in keeping the electronics from burning up in hot countries.

Datasheets

• File:At91sam7x128 256 pc.pdf Atmel CPU
• File:DS2756.pdf DS2756