I don't know if this exists—but—am looking for a slide viewer that you can hook a carousel into yet view in a box as opposed to projecting it. Dad has a zillion slides but at 94 can't handle a projector, etc. Thanks for any help!
I don't think I've ever seen anything handheld that would work with a carousel; the whole affair would be kind of unwieldy.
Kodak used to make a couple of Ektagraphic models, the 270 and 570, that do exactly what you're after. Both are cube-shaped (about a foot in each dimension) and are completely self-contained.
I'd be very surprised if you couldn't find one on eBay or somewhere else for not much money.
I recommend sending the slides in to a slide digitizing service. That way, your father could view them on whatever device is available — computer, tablet computer, smartphone, etc. Unless a "zillion" slides are so many as to be cost prohibitive to have digitized, that is.
Alternately, there are several slide viewers that will project slides onto a built-in screen (usually about 2" × 2" or so). Unfortunately, these viewers do not accept carousels. You have to load the slides individually, or some of them allow you to load a small stack (10-ish) of slides. Some of these slide viewers are powered with batteries and have an internal lamp. The cheapest slide viewers you simply hold up to your eye — they look like an enlarged jeweler's loupe, or a single-eye ViewMaster.