cap question, please help

[chris229 10+ year member]

caps don't get damaged by charging them without a resistor---- the battery cable didn't spark because it was charged---- you can test the cap by removing the power wire and testing voltage---cap help systems by suppling peak current and lowering the supply impedance----a 20v cap CAN'T kill you--- unless the teacher cap was more than 100v there was never a need to use a screw driver to short it

 

[Heresy 10+ year member]

I personally don't know what the cap was rated at that the teacher used. Basically all I saw I got to see is what was left of his "lesson". I was the class that met after it happened and he lectured us about it and actually tried to do it again but it wasn't accepting the charge.

As to where he got the cap, I have no idea. I know he salvaged it from something he had dismatled. And this teacher loved to cannibalize whatever electronic he could find, this included one of the very very old computers that took up a entire room. I guess it yielded quite a few large capacity caps and this is one guess of where they could have come from. Again, I am not sure.

I do know that AC is a lot more lethal than DC. Thomas Edison went for years making that point. At the worst, the cap probably could give you some burns.

 

[Fuel37 10+ year member]

my electronics teacher used to do taht with a cap out of a tv i think. it was like 20k v not sure how many amps but it would make quite a spark when he shorted it with the screwdriver. (he was just different though i don't think there was any method to his madness other than making a spark) one day this dumb guy in our class seperated the legs on a small l.e.d. and decided it would fit into the electrical socket..... that was kool.... hahaha big flash and little bits of led all over the desk...... oh well...

 

[Heresy 10+ year member]

I remember the days of students blowing up stuff too! They did the same thing with resistors, lightbulbs, and anything else they could find. Only about 3 or 4 people passed that class(me included). My teacher was a genius but he had no luck persuading people to listen to him in that class. A shame too 'cause he was dedicated and would help anyone who tried... Anyway, high school electronics usually involve explosions or someone getting electricuted.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Fuel37 10+ year member]

true dat... high school was a blast i just graduated this year.... our electronics teach was a scottish pilot that everyone called "ACE" (he was also bald) very smart man but absolutly no teaching skills. i saw a guy slit his wrist open on a computer case in that class one day and almost bleed to death.. that was interesting..... can't think of what else happened..... i just remember it was a real good time (i didn't do that great cause i was too busy having fun but i was also one of the few that passed)

 

[maylar 10+ year member]

Every audio person should have a DMM. Every automotive DYI'er should have a 12 volt test light. Get one or the other from Radio Shack or KMart.

Pull the main fuse (the big one at the battery side of the wiring) and put a DMM or test light across the cap. You should see 12 volts (light on) there. Put the fuse back in.

 

[chris229 10+ year member]

Originally posted by Heresy

I do know that AC is a lot more lethal than DC. Thomas Edison went for years making that point. At the worst, the cap probably could give you some burns. [/b]

it not about AC or DC ----it is the amount of voltage reguardless of AC or DC. you skin is a resistor and it will takes a high voltage to get current to pass through you body to kill you. 110v DC will kill you just as fast.

 

[Fuel37 10+ year member]

all i know is that it all hurts. i'd sooner be shot than shocked. lol

 

[chris229 10+ year member]

Originally posted by Fuel37 all i know is that it all hurts. i'd sooner be shot than shocked. lol

//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Fuel37 10+ year member]

true dat

 

[Heresy 10+ year member]

I'll admit I was wrong about the AC/DC debate. Thomas Edison was the one who claimed DC voltage was safer than AC voltage and took great efforts to prove his point. This included electricuting small animals and convicts. It was more of a PR campaign against Nikola Telsa's AC current being used in cities. The amount of money wrapped up in DC current was too great for Edison to just yield to AC. Anyway, I guess I believed the arguement without question and never looked into it until I was called on it. One of the better sites to read up on this not so interesting history is http://flyingmoose.org/truthfic/tesla.htm .

I'll just cower in the corner. I admit defeat to chris229. Listen to him, he knows what he is talking about. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[chris229 10+ year member]

Originally posted by Heresy

I'll just cower in the corner. I admit defeat to chris229. Listen to him, he knows what he is talking about. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif [/b]

it's not defeat----just----learned something new thats all--//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Fuel37 10+ year member]

wow is that someone actually being courteous when they were told they were right??? you deserve a medal man !!! too many arrogant people in this world!!