An easy place to start might be to cannibalize the parts from a flashlight or radio. These will be set up to charge 2-4 AA equivalent NiCad or NiMh cells. I’ve not done this experiment my self so don’t have any circuits/schematics handy. I’m gonna go waaaay out on a limb and say you just might be able to find such online.
LOL! Thanks for the suggestion, Professional Engineer. I suspect you are correct, and I’ll poke around and see what I can find. If you should somehow stumble across any in your travels, it would not hurt my feelings at all if you would be willing to share them! Thanks again!