Actually it was a reference to Back to the Future but I am an in-the-closet nerd. lol
OK... just googled 'star trek Flux capacitor' and doc brown wasn't the only one that used one. The flux capacitor was referenced in the episode "Hollow Pursuits" Next Generation and "What You Leave Behind" DS9. According to the "start trek encycolpedia" (who the heck new there was one!) " the existence of a "flux capacitor" in the Trek universe is a light-hearted nod to the Back to the Future series of films, in which the device enables time travel."
I am not a trekkie (although I love all things sci-fi) I am however trying to find ways today to not look at the stock market, so looking up instances of who has used a flux capacitor will do for a little while!