This is a 2-3 year old ryobi 40v lithium battery charger. It has stopped working. I wondered how complex it could be inside… a transformer, a bridge rectifier and maybe a capacitor or two to smooth out rough edges. First I had to find a &@#$)@# torx screwdriver as they don’t seem to want people to look inside.

This is what I found:

inside charger

From the 110vac on the right the circuit starts with a transformer at the bottom, a bridge rectifier and then a 220uF capacitor.. exactly what I was expecting.
Then there was all that other stuff! Wow. Another transformer, some non-power handling diodes, lots of capacitors and a couple of ICs! A friend suggested the rest of the components are a switching power supply. And the other thing to note is the three output leads (red, black and white) to the battery.

A replacement charger is in the $140-200 range so cobbling together something that will charge would be very nice!