OK. I am in the middle of writing a story, and one of the heroes needs to take down a man in armor without using a weapon. Easy, I think. Have him use a stungun on him. But then it occurs to me…isn’t there some substantial padding worn under full armor? Would the resistance of all that metal somehow negate the amperage of the stun gun?
So I put it to those with more knowledge of these things than I: Would a stungun work on a man in full armor?
Well, first off, yeah there’s padding. But how would the ‘prongs’ of the stungun pierce the armor anyway? Even then, maybe the metal armor would ground the charge away from the wearer.
As I remember, full-on steel plate armor went something like:
Plates->chain->leather->cloth padding->clothes->skin
I don’t think it would attach to the armour (if it did, then it would go right through a regular dude)… even if it did, Phnord is right - the current would flow through the armour, not through the guy.
You could always go for a head shot. That should produce some satisfying spittle. 
Also, he would be riding on a warhorse, that is also wearing a fair amount of armor. And he’s in contact with the horse, and the horse is in good contact with the ground (iron shoes). So even if you could somehow make the stun wires stick into his armor, the charge would likely flow from his armor into the horse’s armor and then into the ground.
But maybe that would stun the horse, which would fall out from under him. Maybe even trapping a leg under the horse. Even without that, a dismounted knight is at a real big disadvantage. Some of them with the heaviest armor wouldn’t even able to get up from the ground without help!
Incorrect.
A knight who would fall on the ground could get back up just as easily as you and me.
Articulated plate armor worn on the field of battle was no where as restrictive as usually portrayed in holywood movies.
This misinformation usually stems from the late renaissance period where JOUSTING armor was used in tournament jousts.
Jousting armor WAS rather heavy and thick therefore cumbersome. But a knight would NEVER wear such a suit to battle!
Put him in Roman armour or similar and hit the thigh?
Assuming that you can’t have your person in a mail vest or similar, how about some sort of optical weapon? I was googling for limited shot flash/strobe weapons but couldn’t find any. This site might give you some ideas.
Pepper spray.
Thanks, everyone. Looks like my initial assumption was right…stungun was a bad idea. I think I’ll fall back on the Tom Clancy optical weapon for the time being. Given the number of re-writes these stories go through, it may be something completely different next week. Of course, I could just have the hero use the stungun, and then deal with the “Whatdoyoumeanitdidntwork” consequences…hmmmmmmmm…
Stun gun won’t work on metal armour. Short circuits the jolt.
Unhorse the man in armour. He will be virtually helpless on the ground due to the weight of the armour.
Isn’t a stungun a weapon?? 
Granted a non-lethal weapon, but a weapon non the less.
I’ll point you to my post above. Please read 
Anyway, what kind of armor is the guy wearing? Full articulated plate? Can he be something else? A norman footman? A conquistador?
Well, as written now, the guy is is full articulated armor (the traditional "knight on horseback). The point the hero was trying to make was that armor wouldn’t protect the other guy (sort of an “I am a great wizard…fear me” thing). Partial armor doesn’t work as well for the plot. The guy taken down has to feel, and those around him have to feel, that he is invulnerable to damage from an “unarmed” man (ie not holding a sword or axe or mace, etc).
Ahhh, well nothing like a 12-gauge double-barrelled Remington for just that kind of situations
Is the knight armed? That would make things a lot more difficult. Then again he might so confident that he doesn’t draw a weapon?
How bout something less high tech? A bolo would tangle the legs and take him off his feet.
I had kinda hoped to avoid the use of lethal force at this point in the story. Low-tech doesn’t work, plot-wise. It needs to be something totally alien to the knight and his people, otherwise the hero just looks like an ordinary person, not a “wizard.” I want to use the knight as a character later on in the story, so just bunching his ticket with a .45 doesn’t work either. Oh, well. The plights of an author…
Maybe I’ll just take him out of armor, and make him very large and famed for his unarmed prowess. Not quite as impressive, but it should still work.
Thanks for your input, everyone. Was very helpful.
There are always those ray-type weapons that became popular during the 1920s.
Have your hero tackle then powerbomb him or pull some weird pro-wrestling move on his rusty ass. I know I always feel like I’m watching a magical circus act when the WWE is on…
I am going to second the Pepper Spray proposal!! It would be small enough to fit in the ‘‘wizard’s’’ hand without being seen. All those around would only see a stream coming from his hand. And it would most definitely put the knight on his ass!
A directed gas weapon? Bear repellant maybe?