Originally Posted by chuck H
Here is a video of the John Bedini Earthlight with solar cell. In this one We are using a Dupont #800 water filter with Zinc strips and distilled Alum water. The LED shuts off when there is the correct amount of light. The Zinc is from a sheet sheared into strips and soldered together. It makes only 1volt but as you can see it has plenty of current to run this circuit. The Magnesuim ciruit would leave only about .6volts under this load but the Zinc under load has .7 volts. I have not checked the current draw yet.
YouTube - Bedini earthlight solar with zinc cell.wmv
Chuck---- I'm glad that you got that to work. I worked with this idea all week and found that if you wrap plain old aluminum foil around the cartridge you get almost a volt with enough punch to run the circuit. I used just plain tap water with no additive. The foil seem to hold up amazingly well. You can't beat the cost and availability.
I decided to use an infrared phototransistor between the base and emitter of the 2N2222 to solve the on/off problem instead of using John's way. It is an easy idea but not my idea. I saw it done somewhere before and it works very well except that when it shuts down the circuit it still leaks about 100 to 200 micro amps. For the battery situation we have-- where all we care about is turning the light on and off ---it works just fine. The Radio Shack part# is 276-0145 and here is a link to the part:
Infrared Phototransistor - RadioShack.com
The thing looks like a white LED. The collector (short end) goes to the base of the 2N2222 and the emitter (long end) goes to the 2N2222 emitter. When light hits it the device keeps the transistor from functioning. Sensitivity is controlled by adjusting the base resistance.
I enjoyed your link to the article on magnesium. That really helped.