Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

NiCd Battery Fast Charger

NiCd Battery Fast Charger

An advanced battery charger design based on Maxim’s battery charger IC MAX712. This device can fast-charge an NiCd/NiMH rechargeable battery.
This circuit is from the MAX712 Datasheet, and makes use of the ΔV/Δt and timeout methods to terminate Fast Charging. It is designed to charge two NiCd pencil (AA) batteries, at 300mA. After fastcharge is completed, Trickle charging begins, at 15mA.

Design equations for various circuit elements in the standard application circuits are given in the MAX712 datasheet. These have been used to calculate the values for various components. The indicated power transistor is a 2N6109, which was not available locally. I used an SK100 transistor instead. It works fine, except that since it is in a TO-92 metal-can case, heatsinking is inadequate for supply voltages higher than around 7V.

Construction of the circuit posed few problems, except for high-frequency oscillations observed on the power lines. This was before I had constructed the bridge rectifier stage, and was drawing power from a bench supply through a long wire. It proved very difficult to kill these oscillations (at 1MHz), but a few 0.1μF capacitors did the trick. This is mentioned in case you build the charger without a built-in rectifier. AC power is obtained from a modem power supply transformer. The whole circuit was assembled onto veroboard. Connectors for the AC jack were inserted after cutting three holes in the circuit board, and using large amounts of solder to hold it in place.

Visit Here for more.

 

More Articles to Read

uArm Swift is an open-source robotic assistant for your desktop
uArm Swift is an open-source robotic assistant for your desktop
Make your reflex punching bag interactive with Arduino
Make your reflex punching bag interactive with Arduino
DIY thermal imaging
DIY thermal imaging
Teardown, experiments and calibration of an Ist-Rees laser spectrum analyzer
Teardown, experiments and calibration of an Ist-Rees laser spectrum analyzer
IR thermometer hacked into an IR camera
IR thermometer hacked into an IR camera
Real Time Planet Tracking System
Real Time Planet Tracking System
Bookcase automatically opens to reveal secret lair
Bookcase automatically opens to reveal secret lair
PCI Express High Performance Reference Design
PCI Express High Performance Reference Design
Muxtronics open source 12V powerbank
Muxtronics open source 12V powerbank
TI’s Little Professor
TI’s Little Professor

Top




Shares