Mesing whith kV and caps

[Someone Electro]

I made an voltage mpltipyer that produces 1.2kV and it charges an 1uF cap

if you short the cap it make a loud bang an a big spark :twisted:

how degarus is it to toch the contacts of such an fuly charged cap?

It burns pencil tracks on paper (looks like an miniature fireworks display)
I put an 220 Ohm resistor in so wen it arcs ower it dosent BANG so loud

how much capacitance wod an thin plastic bag sadvichd betwen two plates of aluminium foill (ech foill about 10dm2)

 

[Nigel Goodwin]

I made an voltage mpltipyer that produces 1.2kV and it charges an 1uF cap

if you short the cap it make a loud bang an a big spark :twisted:

how degarus is it to toch the contacts of such an fuly charged cap?

Like any electrical shock, it varies wildly from person to person, but it's certainly potentially dangerous. Even if the shock isn't enough to kill you, it could easily make you injure yourself! - perhaps even fatally?.

 

[Someone Electro]

I wodnt be stupid enught to try.

But i toched an 2uF electolic cap filed to 200V.Ahhhhh! I was still ok.it was farr from faital.My finer ony hurt a but for 5 seconds

my multimter shows 3 MOhm ressistance of my fingers so Ohms law 1200V/3000000Ohm = 0,0004A = 0.4mA Huh?!? :shock:
Soo litle? but that is farr from harmful.I reed that 30mA is harmfull

Hmmmmm..... I dont get it

btw:how much capacitance dose two aluminium foils seperated by a thin plastic bag have(10dm2(cubic decimeters))? (my gues is 5-10nF)

I still like the arcs that the cap produces (the gap is 1mm).they look like blue firebals

 

[Nigel Goodwin]

I wodnt be stupid enught to try.

But i toched an 2uF electolic cap filed to 200V.Ahhhhh! I was still ok.it was farr from faital.My finer ony hurt a but for 5 seconds

my multimter shows 3 MOhm ressistance of my fingers so Ohms law 1200V/3000000Ohm = 0,0004A = 0.4mA Huh?!? :shock:
Soo litle? but that is farr from harmful.I reed that 30mA is harmfull

Hmmmmm..... I dont get it

The resistance of your skin varies greatly, though it would be unusual to be as high as 3MOhm?. Testing it with a multimeter (particularly a digital one) won't give the same sort of reading as measuring it with 200V applied 8)

btw:how much capacitance dose two aluminium foils seperated by a thin plastic bag have(10dm2(cubic decimeters))? (my gues is 5-10nF)

There's probably a formula for working it out?, but I suspect it would be easier to make one and measure it!.

I still like the arcs that the cap produces (the gap is 1mm).they look like blue firebals

Try a 100-200uF charged to 320V or so (main electrolytic in a TV set), it will destroy the end of a screwdriver!. It's not fatal though, at least it never has been on me so far? - a number of TV's have a nasty habit of leaving the capacitor charged up when the PSU blows up (Grundig sets are particularly bad for this!).

 

[Someone Electro]

I dont have an instrument to mesure resistance(got a basic multimeter R(0-20HOhm),V(0-1000V),I(0-20A)) But i cod also try to make one, charge it to 1.2kV and then discharge it whith an metal object to see a how big bang doe it produce


I seen someware an plastic yougurt cup whith aluminium foil on the inside and one on the outside makes an good HV cap (15-20kV)

I also tryed to charge an 100nF 250V cap to 1.2kV It holded charge until it got charge to ybout 1kV and then it clicked and vas proboly destroid

It aslo flashed an flourecent bulb(I have a tube from an 11W flourescent light bulb(ones you can screw in insted of norman flagment bulbs))wen you toched it.If you hold the tube in your hand the volage vod regulate to the lamps operating volage an the bulb lites up.But its blinking at 50Hz(It conected to two mains transformers whith one in backwards(I dont want woring whith mains!))since the bulb is demanding more than the volage mutiplyer can produce

Well the comany isent expeting an idiot toching it whithut discharging (so they didnt put it an discharge circut)

 

[chemelec]

Wet your fingers a bit and you will find out your resistance is MUCH Lower than 3 megohms.
Or Better yet, do a Resistance test at a Higher Voltage of about 50 volts and using a Micro-Ampmeter. Than Calculate the Resistance with Ohms Law.

A Multimeter doesn't have enough potential to give an Accurate Reading for Skin Resistance.

Although a DC Current isn't as dangerous as an AC Current is, You Are Stupid to grab a cap charged at these voltages. Especially larger capacitance ones.

Just because it hasn't happed yet, It DEFINATELY has the capability to Stop your Heart.

 

[Someone Electro]

I meade the mesurments:
-from left hand to right 0,35mA-142kOhm
-finger whith probes half cm apart 0,73mA-68kOhm

at that resistances the curent shod be(at 1200V):
-hands 8.5mA
-finger 17mA

what!??!This certanly isent right or was the rasistance so big(i most of the times have realy dry hands)

whith moist fingers its 20mA.Well is aproching fatal curents but you wod still survive.its 24W runing thru the finger(i shure wodnt want that)

Ok back to the homemade capacitator

i made one out of two shets a alufolium and a well.. a garbege bag.

ech sheet was 13dm2 and roled together it was 30cm long so i folded it 3 times.conected it to the voltage multiplyer and after abot a second a pop was herd from the cap!
BAD news!So it was ovius that the cap arcd inside.The first sufpect was my conctrucion but i codnt find out anything so the second siuspect was the gabage bag.
I chose it becose its realy thin.Next was the arc test of the gabege bag.I tock a pece of the leftovers from cuting it and conected the cultipier on bouth ends and yep it arced right thru it!
But it was able to store charge i estemate it bay the spark size at 100nF (compared it to an 100nF cap and the sparks ware alot identical)

I think i had enuf HV experementing for a wile

I think i got huked to PIC microprocesors (at microchip an PIC 20Mhz,18pin...)
Its amazing itat it only needs 150uA to run at 20Mhz and they cost $1 or 2 or even half a dolar!

 

[bmcculla]

5mA through your heart will kill you. With good medical electrodes a 9V battery will run this current through you.

With dry skin anything below about 60V shouldn't be dangerous but you should still be careful.

 

[Someone Electro]

how can medical electrode get the resistance sooooooo far down?

50V AC from an mains transformer can be fum making your finger vibrate up an down at 50Hz

 

[zachtheterrible]

id imagne that 1.2 kv would jump. could it even jump past the dry part of your skin?

hey electro, try discharging that 1.2kv through a smaller cap that doesnt have vents, im sure itll make quite a nice boom boom :lol: . just make sure ur plenty far away, i dont know if it might throw shrapnel?

why do caps have to have vents!?!? im gonna try getting some jbweld and "welding" the top of a rather large capacitor shut, then connecting to mains :twisted: . if i get a capacitor that is rated for 200volts, itll still blow because of peak voltage, which is above 300v, for 120vrms, right?

 

[bmcculla]

Medical electrodes are silver covered with silver-chloride. The chlorine atoms act as charge carriers. The also use a special gel to get a really good connection with the skin.

 

[Someone Electro]

charging an 200v electrolic to 300v wodnt blow it but it wod dramaticly decrese life time

the 1uF cap i use is rated at 400V (I think its poiester)but it handles 1200V like it was 400V

I tryed it on an 100nf 250V cap and the only thing hapend was the pops coming from the inside

I laso tryed to pus the 1uf charged in to the tables structure.It arcd thru the paint and pulverising it (loud bang)

too bad Electric Raian iset online enymore (we ware frends(we bouth make dumbass experements))

by the way:anybody here knows anything about PIC microprocesors (i think i got hoked to PICs)
Nigel is proboly an expert at this stuf.

 

[andrew2022]

ive accidently touched a 400V 47UF cap before. got a nasty belt from that

 

[spuffock]

If you poke the ohmmeter prods through the skin you will get a LOT lower resistance :twisted:
The first thing a kilovolt will do to the skin is burn itself a couple of holes. If you had the kit to measure the peak current, I would expect to see a peak of several amps!

 

[Nigel Goodwin]

If you poke the ohmmeter prods through the skin you will get a LOT lower resistance :twisted:
The first thing a kilovolt will do to the skin is burn itself a couple of holes. If you had the kit to measure the peak current, I would expect to see a peak of several amps!

I can't say I've ever tried sticking prods through my skin (and I'm not going to!), but a shock like this DOES burn holes through the skin at the contact points. A 'good' shock can kill the skin for half a cm or so! - but it grows back 8) (eventually!)