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Candle Power:
A single lit candle in conjunction with an inexpensive thermopile voltage generator
provides enough power to charge a small battery when used with a small low voltage
DC to DC converter.
Do It
Yourself Portable Cell Phone Charger
It seems that as cell phones become more sophisticated, their operating times become
shorter and shorter. If you are on the go all the time and have difficultly
finding AC or DC outlets to charge your phone, you might consider this simple
scheme....
Solar Powered Lithium Ion Battery ChargerNEW The circuit below feeds a
controlled current and voltage to a 3.6v lithium ion battery. The current is limited
to 300ma and the voltage is limited to 4.2 volts. The circuit uses a LTC1734 IC from
Linear Technology. No diode is needed between the circuit and a 6 volt solar
panel....
Solar Powered Cell Phone Charger The simple circuit below regulates the
voltage from a 6v solar panel to a fixed +5v. That voltage can be fed to any
cell phone or USB connected portable device, to charge its battery. The
circuit uses a Reg113-5 voltage regulator from Texas Instruments. The tiny device
can handle up to 400ma of charging current. I would suggest using a solar
panel rated for less than 2 watts and one which contains 12 solar cells. One
such panel is shown below.
Two 12v
Battery Isolator: Linear
Technology has just announced a neat little chip (LTC4412). It has been designed to
be used in conjunction with an external P-channel power FET, to form an ideal diode
function with a very low 0.05v voltage drop. The chip monitors the voltage on either
side of the FET. As long as the voltage on the drain side is greater than the source
side, the FET is turned on....
Links to electronic circuits, electronic schematics, designs for engineers, hobbyists,
students & inventors:
1.3V Power Supply - This is a replacement power source for 1.3V mercury
cells or other small batteries. It has many uses and I use this circuit in my computer
to power a front panel multi adapter which has a digital thermometer… [Aaron Cake's
design]
12 Volt Gel Cell Charger - Recently, a fellow amateur was looking for a gel
cell charger which would first charge at a fixed rate and then later switch to a
trickle charge when the cell was fully charged. After reviewing several catalogs and
web sites, the MAX712 IC was discovered. This IC meets all the requirements for
almost any type of battery charging system. The circuit in Figure 1 was designed
specifically for 12 volt gel cells..... [Radio Amateur Society of Norwich]
12V input 12V battery charger - Well suited for charging gelled batteries
from a car, with the engine running or stopped. [Manfred Mornhinweg]
12V, 4-AA Cell Differential Temperature Charger - This project
makes a number of improvements over my Temperature Controlled NICD Charger
circuit. The new circuit runs on 12VDC, allowing it to be used in a car or
from a 12V solar power system. Additionally, a current sensor LED verifies
that the cells are receiving charging current. Note that the current
sensor circuitry... [G. Forrest Cook]
3.3V Lithium Cell Supply Requires One Inductor - 08/05/99 EDN-Design
Ideas Because of growing popularity of lithium-ion (Li-ion]batteries
and 3.3V power supplies, portable-equipment designers must often create a
3.3V supply that a single Li-ion cell can power.... [Design Idea by Matt
Schindler and Jay Scolio, Maxim Integrated Products, Sunnyvale, CA]
5v Solar Charger - This project uses the 1.2v rechargeable
battery and solar panel from a Solar Garden Light. These lights can be
bought for less than $5.00 in most $2.00 shops or similar shops that sell
general household items…..(diagram added 05/07)
A Solar Cell Battery Charger - A Simple Regulator for Charging Lead Acid
Batteries from a Solar Cell....(electronic schematic added 12/08)
Amplified Zener - A 13 volt Zener diode will work well for charging a 12
volt battery on Standby use. Or use a 14 volt zener a diode for a Standard 14.6 volt
charge…. (circuit / schematic design added 10/06)
Atmel Solar Panel Battery Charger - Batwatch is a simple monitor for a solar
panel battery charger, using an Atmel ATtiny13V. It periodically measures the charge
current and battery voltage, and shows them by blinking two LEDs. I built this circuit
into the plug of a VW solar charger panel that is used to prevent a discharge of the
battery when a car is not used for some time. A modern car contains a large amount of
electronics, and a quiescent current of 40-50mA (about 1Ah per day!) is considered
"normal". ….(Circuit design added 11/08)
Automatic Trickle Charger - Scroll down to find this circuit. Here is the
schematic for the automatic charger I have been using for my kids' battery cars. The
charger is a small molded unit that probably doesn't supply more than an amp and this
circuit would have trouble with much more. No current limit is provided by this
circuit....(electronic schematic added 05/05/05)
