Micro Controlled Battery Charger

[PeterDove]

Hi All,

After posting my instructable

**broken link removed**

I decided I wanted to make a more complex micro-controlled charger. Now the main problem I came up against was how to control the current coming out of the L200C - since it needed a resistor there to limit the current. After reading up a small amount on resistor networks etc and using transistors as switches I came up with this

**broken link removed**

The 5 switches represent the PIC turning on or off the 5V at each of the PORTA 0..4. As it turns each one on or off it causes current to flow(or not) through each of the transistors. Because the resistors are in parallel here we can get quite a range of values, from 100mA to 2A ( which is the max of the L200C ). So this appears to me to be a nice Digital to analogue convertor which allows me to control the current. The reason the voltage source is 0.45 is because that is what is coming from pin 5 of the L200C.

I am not a experienced PIC programmer ( only read not done! ) but this seems like it could work - anyone know any different?

Peter

 

[justDIY]

should work ... there is a similar example in the LM117 family datasheet

 

[PeterDove]

should work ... there is a similar example in the LM117 family datasheet

Just looked it up now, thanks.

Peter