He he he … well you did make me laugh a little austingirl. Whether the unit has “auto sense” (i.e., the machine goes “on” when the needle is inserted) … or, if they use a foot switch to turn on the current, there is no difference. It’s like this:
Suppose the therapist sets the DC at 0.5mA. She starts the machine (either by foot, or by auto-sense) the current goes “on” and the amount you get is the pre-selected 0.5mA. And, that’s it.
“Current” usually refers to actual electrons moving through a conductor (in this case your body). “Voltage” is like the pressure needed to push those electrons through the body, (there is always resistance to current flow … unless, I think, you get to absolute zero?). The setting on the meter is a selection of current (or electrons, if you will), that travel in the body.
“Constant Current” means that if you select, say, 0.5mA … the voltage (pressure) will automatically go up or down to maintain that “constant current” flow of electrons.
Gosh, I hope I’m right on this. Maybe Brenton can help me on this. I think I basically got this right. The important thing? NO WORRIES, if it’s auto or foot switch … same thing.
I think the auto-start works by having an infinitesimal amount of current at the needle all the time. When the machine senses a change in conductivity/resistance (as from “no connection” to “wet body tissue”), the unit switches the current “on.” It’s a nice feature. Again, I might not have this entirely correct.
(Amazingly, there was an unending discussion about whether current goes from + to -, or from - to + Old literature said that there was a “buildup of electrons” at the “plus” pole and then went to the “negative” or electron-deficient pole. Today, it’s just the opposite. And, don’t even read this last paragraph, it’s BS for sure. True, but BS nevertheless.)
This electrical stuff is NOT my area of “knowing” at all, so wait for a much better explanation. Please … help here folks!