Any USB port can supply 5V at up to 500mA. The USB standard specifies that a device may not use more than 100mA until it has negotiated the right to use 500mA, but apparently no USB ports enforce that requirement. This makes the USB port a convenient source of power for devices such as this charger. [via]
USB AA NiMH and NiCd Battery Charger - [Link]
A flyback converter implements a current-limited power supply to charge lead-acid batteries. The MAX773 current-mode controller limits the output current and the flyback transformer provides isolation and flexibility for input voltages both above and below the battery voltage. The MAX471 current-sense amplifier monitors the charging current and feeds back to a threshold detector so that below a designed threshold the flyback converter can switch to a lower charging voltage for trickle-charge mode. [via]
MAX773 Lead Acid Batteries Charger - [Link]
Mark: To keep the lights on and the camera going I have a multi-purpose battery charger. This contains around 24Wh of energy storage in eleven NiMh AA cells and circuitry to charge my laptop, satellite phone, mobile phone, camera battery and a PP3 for Ju’s Dog Dazer. It can also power a white LED tent light that sheds just about enough light to cook by. A cunning design means that some of the AA cells can be removed from the internal battery stack and exchanged with flat ones from a torch or whatever. [via]
Multi-purpose charger - [Link]
I think this subject will always get new project because of the spread of the ipods. People will always want to charge their iPods when their away or any mod to an iPod will always show interest for the public.
The circuit’s pretty simple, basicly it’s just a voltage regulator. Both the LM317 and the REG1117A (LDO) fit the PCB, maybe there are even more types that I’m aware of that can be used on it. I did add one extra thing: a LED that shows if the connected device is consuming power. To do this I used a shunt resistor and a current converter. [via]
USB iPOD Charger based on REG1117A - [Link]
This cheap and easy to build NiCd/NiMH Battery Charger is suitable for automatically charging a wide range of batteries for many applications. Proper chargers are usually expensive and cheap chargers supplied with the original equipment often incorrectly charge the cells and dramatically shorten their life. This ‘intelligent’ charger was designed for high current and rapid charge applications such as cordless power tools and model racing cars. These battery packs are expensive and sometimes difficult to purchase. This charger uses the cell manufacturer’s recommended charge method, to safely and quickly charge batteries.
Intelligent NiCd/NiMH Battery Charger - [Link]
Freeloader Solar Charger is the pocket size solar charger and can store the power up to 3 months.You can use it to charge your electronic gadgets such iPod, mobile phone, PSP, PDA anytime, anywhere.This device is suitible for any traveller.
Freeloader Solar Charger - [Link]
This is a NiCd/Ni-MH charger that can charge with constant current and automatic charge termination when the total voltage for all cells reach the setting voltage.
Ni-cd charger - [Link]