During our tracks relationship with family and friends provides us with a cell phone. Unfortunately, during his work is limited to about three days, and any charger, we can not help – No source of electricity: power outlet or car.
The only source of electricity is treke- penlight batteries used in flashlights, ratsiyah, the receiver (here I do not see exotic sources that are used in long-term base camp – Gasoline, solar, muscle, wind genegatory).
There chargers for cell phones that use such batteries, but they are rare and are expensive. I suggest that such a device with your hands. You will need a desire, hands and a bit of time, but also the ability to solder will not be superfluous.
The figure shows a diagram of the device. A few words about the scheme. As the controller chip LT1307- one selected from a large number of chips to control voltage conversion. The chip is enabled by the scheme recommended by the manufacturer, but the inverter supplies unstabilized voltage and constant current required for zaradi phone battery.
Voltage feedback to stabilize the current shunt is taken from R102 and to the input 2 chip, this chip is committed to maintaining the input voltage of 1.2 volts, ohms shunt resistance 12 means an output current of 100 milliamps.
If an output of the inverter is not connected to the phone, the entire load on the zener take VD102 and VD103, while it is strongly heated. Switch from the inverter is not and it starts to work immediately after connecting the battery, the LED VD104 used for process control with full battery discharge finger he goes.
The housing is arbitrary, then verify that the circuit is filled with hot melt to protect from moisture. Details: choke inductance L101 10 microHenry and current up to 100 mA at 6.2 V zener diodes and a current capacity of 100 milliamps, the diode VD101 necessarily Schottky diode voltage more than 20 volts and a current of 1 amp.
A warning: do not turn on the device with unconnected phone, it leads to wasting batteries and heating of the converter.
Andrew Andreev19 March 2012 at 00:33