July 27, 2003
Charge Controller for Kinkajou
Photovoltaic (solar) cells and human-power generation represent two possible means of recharging batteries in off-grid rural communities. What we need a simple, low-cost robust circuit for connecting both DC appliances like the Kinkajou microfilm projector and their batteries to various power sources.
What we're looking for is a circuit for the Kinkajou that we can connect to something like a pedal generator or solar panel and:
- run the Kinkajou directly from the renewable power source
- run the Kinkajou while charging the batteries with the extra juice
- charge the batteries directly while Kinkajou LED is switched off
The charge controller has to be smart enough not to overcharge the batteries, and it can't overdrain the batteries when the generator is off. In addition to the Kinkajou projector, such a circtuit could be applied to any battery-operated device intended for rural communities, like a radio or Light Up the World's solid-state home lighting systems.
Posted by Timothy Prestero at July 27, 2003 11:56 PMThis looks like an interesting and useful design challenge. What I don't understand are the constraints that make existing, commercial charge controllers unsuitable for this application. Can you elaborate? For example, let's pick the criteria that the device be built from locally available components. Central to practically all "smart" charge controllers is a microprocessor, yet these are manufactured only in a very small number of countries. Even India, with it's abundant semiconductor design expertise has no significant VLSI fabrication facilities.
Posted by: Tim McNerney at January 3, 2004 03:30 PM
