[OpenTRV-dev] OT: Charge battery

[Kevin Wood]

> are the reason for the buck converter that it can adjust the voltage above
> the input voltage from the PSU ?

No, although you could use a boost converter instead to achieve that. I
suspect the prime reason for using a switching converter is efficiency and
to reduce size and heat dissipation. I think the ap note was aimed at
small battery powered appliances using AVRs.

If you're not so worried about efficiency, you could make the pass element
a simpler linear device, but still control it using a voltage derived from
one of the AVR PWM channels. You could do something similar to make an
active load for testing the batteries.

Best Regards

Kevin