Do you remember those clunky boxes with a large plunger used by cartoon coyotes and mustachioed villains in old cartoons to set off dynamite? Those are absolutely a real thing, and are called exploders.
Sometimes known by the arguably more technical names 'shot exploder' or 'blasting machine', these boxes housed a generator which generated an electric current when the plunger was depressed. This current traveled down a wire to the blasting cap, which set off the main charge.
Exploders were originally fairly large -- the cartoons have the scale just about right -- and took some effort to depress the plunger, as the rod is covered in teeth, in order to spin a gear as it descends, which in turn spun the dynamo. Just to be extra safe, the rod was also the 'pin' that completed the circuit once fully depressed, so that an unexpected electrical discharge wouldn't kill the workers when they were setting the system up.
Modern systems use a battery and work with the push of a button, often by remote control. They are unassuming and small, but may take a degree in electrical engineering to use properly. No self-respecting cartoon villain would be caught dead using one.