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Unread postPosted: Thu Aug 25, 2011 9:13 am
Author: Hotwired
FFFFFFUUUU

Zapped myself with the pointy end.

Teach me to have two hands on it at the same time.

For the record there isn't room for two hands on it.

jackssmirkingrevenge wrote:Very nice! Looks like it would fit in a largish pistol grip...


Could do but the plan for this one is a semi-remote ignition box. Wire up a chamber as required and set it off.

Unread postPosted: Fri Aug 26, 2011 4:46 am
Author: Crna Legija
Can you use any type of capacitor because I de-soldered a few from random electrical things i pulled apart they are really small 7mm in dia and 10mm long will that matter? and is the little Gray strip the negative?

dam I really am cheap lol could go buy one for a few bucks lol.

edit: forgot cap specs 440v 0.47uf

Unread postPosted: Fri Aug 26, 2011 5:43 am
Author: Zeus
That should do fine, just make sure you can remove it if it doesn't perform as you'd want.

Don't use any that look like a can, they won't work as well.

Unread postPosted: Fri Aug 26, 2011 6:08 am
Author: Crna Legija
i just remeberd i have the high voltage part of one of these Image portable TV's it works by its self but can only make 1mm long arks, can i dump the cap though it?

Unread postPosted: Fri Aug 26, 2011 6:58 am
Author: Hotwired
What is "the high voltage part"?

The exact item you need is a high ratio coil, if it's not a coil then no.

As for the capacitor it's a polarised electrolytic, unlike the plastic capacitors you need to make sure that's the right way round in the circuit or it can be charged in reverse and fail if not actually burst its case.

Ideally you want a plastic type capacitor.

Unread postPosted: Fri Aug 26, 2011 7:10 am
Author: Crna Legija
Hotwired wrote:What is "the high voltage part"?

The exact item you need is a high ratio coil, if it's not a coil then no.

inputs is 4aa out put is a 1mm thick blue arc so i guess it is.
[youtube]http://www.youtube.com/watch?v=m1F-z8ciNvk[/youtube]
Hotwired wrote:As for the capacitor it's a polarised electrolytic, unlike the plastic capacitors you need to make sure that's the right way round in the circuit or it can be charged in reverse and fail if not actually burst its case.

Ideally you want a plastic type capacitor.


Like
Image but blue? that's what the one i have looks like[/youtube]

Unread postPosted: Fri Aug 26, 2011 3:21 pm
Author: Technician1002
The high voltage part is the power supply to light the cold cathode tube for the LCD backlight.

Unread postPosted: Fri Aug 26, 2011 5:21 pm
Author: Hotwired
Yes the red capacitor here is exactly the type you need.

Image

When you said a stripe on one side I thought you were meaning a polarised electrolytic which has a very distinctive stripe down one side.

With the plastic ones it doesn't matter which way round they go. Charges either way.

The transformer on the HV circuit is certainly producing a few thousand volts, at relatively high current it seems since I saw smoke coming off the wires.

However it looks physically small and not suited for trying to do tens of thousands of volts. The windings are not very substantial and the pins are a few millimetres apart.

I'd keep that as a HV source in itself if you can run that on batteries already, perhaps add a voltage multiplier and see how far you can step up the voltage using that as a base.

For continuing the path of this thread, I'd grab a miniature ignition coil instead from say a scooter, mini-moto or similar.

The only suitable HV coil I can think of in common consumer electronics is the flyback transformer in CRT devices and then again that's questionable because it's quite large, heavy and has many surplus windings which on modern flyback transformers are potted in epoxy so you're stuck with them.


However you've just reminded me I have a circuit from a mini plasma ball which I recall put off a few thousand volts. I may examine that again.

Unread postPosted: Thu Sep 01, 2011 6:46 am
Author: Hotwired
Something just arrived in the mail :)

Image

However to my disgust the circuit merely bumps up 2xAA to ~ 400V to charge a chubby capacitor.

I was hoping for the type which, yes bumps up the voltage to ~400V but then has a 3 stage multiplier after that for over 1000V output.

Now I need to do my own multiplier :?

One step closer to a higher powered version anyway.

Unread postPosted: Wed Sep 21, 2011 12:57 am
Author: jazzman56
This may sound dumb but, it's 30,000 volts but at a very low amperage so that if you jab someone it will not permanently disable them. :shock:

I am a novice in the electronics field and am having trouble of how each component plays it's role in the circuit??

EDIT MR Crowley,
Yes i know it's for a spark strip for a combustion cannon but, if i'm wiring it up etc. and accidentally jab myself i won't knock myself out. Just making sure before i get any ideas of undertaking this project.

Unread postPosted: Wed Sep 21, 2011 1:04 am
Author: MrCrowley
jazzman56 wrote:This may sound dumb but, it's 30,000 volts but at a very low amperage so that if you jab someone it will not permanently disable them. :shock:

The goal of this stun gun isn't to use on people, if that's what you were inferring.

It's for an ignition circuit.

Unread postPosted: Wed Sep 21, 2011 1:35 am
Author: Hotwired
jazzman56 wrote:Yes i know it's for a spark strip for a combustion cannon but, if i'm wiring it up etc. and accidentally jab myself i won't knock myself out. Just making sure before i get any ideas of undertaking this project.


People react differently but being knocked unconscious I'd say was... impossible unless you did something really stupid and got the voltage across your brain which would require significant effort to do so.

The way a stun gun works is it locks up your muscles by spamming them with electrical pulses causing them to contract. There is the potential for that to happen however this is a much lower power device than your average stun gun and the effect, should it happen at all, should be much less, more painful than incapacitating.


The key thing is to never have a scenario where you are in contact with the high voltage AND unable to turn the circuit off.

The switch you can see on the white boxed circuit is:

1) Insulated - it's made of rubber on a plastic box. Pressing the switch cannot result in contact with electricity.

2) Momentary - press down firmly, the circuit is live, let go and it's off. The circuit will not stay on without you holding the button down.


In the scenario you give there is no reason whatsoever for you to be wiring up a circuit that is attached to a battery.

That's extremely dangerous especially if you are not 100% on how it works.

All switches should be off and battery removed before you do anything with it.

The capacitor on the circuit may hold a charge of a few hundred volts and could shock you once if you don't short it out or add a resistor to drain it when power is removed but aside from that the circuit is safe to fiddle with.

Unread postPosted: Wed Sep 21, 2011 2:02 am
Author: MrCrowley
jazzman56 wrote:EDIT MR Crowley,
Yes i know it's for a spark strip for a combustion cannon but, if i'm wiring it up etc. and accidentally jab myself i won't knock myself out. Just making sure before i get any ideas of undertaking this project.

Ah, that makes sense. You didn't end your previous comment with a question mark so I assumed you were making a statement.

Unread postPosted: Wed Nov 02, 2011 3:28 pm
Author: nathanhd123
Hotwired, could you post some links to the websites you use to buy things for this project. Thanks.

Unread postPosted: Wed Nov 02, 2011 6:01 pm
Author: Goats spudz
i have jabbed myself with one of these before it hurts badly but it wont harm you :D


and hotwired will this work without the spark gap?