I have to confess that the two stainless steel Wittnauer Electro-Chrons below are two of my favorite watches. Those hands are so.....kewl!

The Electro-Crons featured the Landeron 4750 movement which first appeared in 1960...only three years after the first Hamilton 500. I also own a Clinton and Waltham with this very interesating movement.

There were two types of Electro-Chrons: most had a large, now-obsolete, WD-5 battery while others had a rechargeable cell.

Although the electronic Wittnauer in the last image doesn't quite have the same appeal as the Electro-Chrons, the dial logo with the transistor and atom symbols are a nice period touch (although not as stunning as the Waltham). This one contains the ESA 9150