Battery Charger

Battery Charger - how to make charger in Realizer.
In this text is explained how a charger works and how to create one. A NiCd/NiMh works with a fixed current. This charger has a high (1C) charge current and a low (1/10C) maintenance current. The charger acts when the start button is pressed. If the current is too low in case of a defective battery the charger or the battery voltage is too high the error led starts blinking, and charging stops. After 60 minutes the charging is ready and a low current charges the battery for 2.5 hours.


A state diagram is used for different actions: Standby, charge high, charge low, and error.


The Realizer simulator is used to test the schematic.
The three outputs on the right are activity LEDs, if the charger charges highcurrent the top LED is on, if it charges lowCurrent the middle LED is on. And the bottom LED is power activity, and blinking when error. In the picture above the battery voltage is too high so error blinks.


Prepared for devices: ST2212G2 ST7FLite10 PIC16F88 other devices can be used by reconnecting I/O pins.