How to make a spark gap

[Lance]

I have seen the 5V rail of an ATX PSU completly melt the standand insulation and burn up the wire before shutting down. The 5V rail will supply a massive surge of current when shorted, easily enough to cause general mayhem and damage.

[YT2095]

I have seen the 5V rail of an ATX PSU completly melt the standand insulation and burn up the wire before shutting down. The 5V rail will supply a massive surge of current when shorted, easily enough to cause general mayhem and damage.

 

Thank You!

 

I`m Vindicated at last!

I think you`de also agree that anyone holding Onto such a wire would also receive severe burns as a result too.

[5614]

If what Lance said did happen then I agree that holding the insulation would not save you.

 

However I have held the 5V rail/wire whilst it sparked and I'm still here.

 

What you're saying can happen, but that doesn't mean it will. However obviously one shouldn't take the risk.

[concrete_hed]

thankyou everyone for your feedback. Especially woelen for the link. One final question. Where did u manage to get a 40,000μF capacitor? What sort of capacitor is it?

[YT2095]

you`ll get capacitors like that out of old computers easily, I once had 5 131,000uf capacitors out of an old Wang Mainframe

 

if you go to an automotive shop, where they sell hi-fi systems for cars you can get 1 Farrad caps there too! (used for subwoofer Amps as a reserve).

[concrete_hed]

Say i had a car ignition coil ( i dont really but i could get one ), how would i connect it to give me just one quick spark. Without making any complex circuit. Something as simple as tapping the ends on a battery or using a charged capacitor. Any ideas?

[Lance]

Say i had a car ignition coil ( i dont really but i could get one ), how would i connect it to give me just one quick spark. Without making any complex circuit. Something as simple as tapping the ends on a battery or using a charged capacitor. Any ideas?

 

You could make oscillations by dragging a nail across a steel file.

[Pleiades]

If you just want a momentary spark, you should do what KFC said and use a Piezoelectric Igniter (http://www.americanpiezo.com/products_services/ignitors.html) you can get these out of some of the fancier cigarette lighters. You know you have a lighter with one because of the way it feels; you’ll feel increasing pressure as you press the igniter button, then it will give and make a ‘clack’ sound, and you should see a small spark. You can also find them on old barbeque grills, the big red button that some models have is a piezoelectric igniter, usually a more powerful one. The bbq ones have two wires already, but the ones form lighters need a wire soldered onto the brass bit on the end.

 

These can make a spark that will go 6 or 7 mm. they hurt if you shock yourself, but not much. I managed to build one into a pen; I could shock people with two small wires coming out of the tip of the pen.

[YT2095]

but non of that uses a 12 car batt as Outlined in his original post.

 

anything outside of this would be Off Topic.

[concrete_hed]

ok, i have done some experimenting with batteries and coils. I noticed that when a battery is connected directly to a coil with no other components in between it creates a spark when you remove the battery, this is because as the magnetic field collapses, the energy needs somewhere to go so a spark jumps to the closest earthed object. I want to use this principal to create a spark that would jump accross a small gap, and i want the gap to be at the end of a long piece of wire (away from me). I know its not good to connect a battery and a coil directly like that, but all i want is a working spark, i can work on improving it once i have the basic concept. Any ideas?

[YT2095]

you`re correct, connecting a coil across a power source for any duration is a great way to get them nice and Toasty! unless they`re Rated for that purpose.

and the spark created by the back EMF is more than capable of Stunning you momentarily, so excersize caution.

having gotten That out of the way, If you wish to make your sparks this way, then you`ll simply need to atatch one lead of the coil to a batt terminal, then the other lead of the coil to one side of your lond wire and the other to the remaining batt terminal.

then proceed as you have been doing.

at the end of your long wires you`ll get a tiny arc if they`re correctly spaced and the wire resistance isn`t too great

[concrete_hed]

in the method you replied above, the way i read it, the coil has 3 leads? how do u get a coil with 3 leads? did i read it right or am i just stupid? or did u mean connecting the two leads of the battery to two long bits of wire (for the spark gap), with a coil parrellel in the middle?

 

sorry if my explanation is crap

[YT2095]

the easiest way for me to explain is to put your coil across your batt but with a switch in line, so it connects Ony when you press the switch.

the arcing will occur across this switch`s contacts, the ideal place to run to wire from to what ever you want to spark.

this whole idea/method isn`t very elegant at all, but will provide what you asked for using the parts you have.

[concrete_hed]

ok i get you, thanks

[concrete_hed]

this is probly the last question i will ask on this thread. How are explosives detonated? You know like a car bomb that is about the size of a cellphone you see in the movies, just before they explode you can hear a buzzing sound that gets higher and higher as if something is charging up and then BANG! Is this the sound of a magneto spinning? What device is used to detonate the bomb?

[Pleiades]

Any sounds heard before a bomb goes off on TV are just sound effects. In reality a bomb could be detonated without any sounds (except the sound of the explosion of course). The basic principle for electronically detonating a bomb it to heat up a piece of wire using electricity, this gets hot enough to detonate a small charge of sensitive explosives, this small explosion sets off the larger one almost instantaneously. This is grossly simplified, but I’m not going into any detail.

[Mole]

I have a similar problem.

 

I need to get a Spark from a 9V battery, using a remote control. I've built several Spudcannons and So Far I've had no problems using peizo-electric ignitors. However, my latest spudgun is a big big. I've got approx. 1.5m of 4" diameter combustion chamber. I'm not too comfortable holding that on my shoulder, because if it goes pear shaped, It'll probably take off my head, and that's bad, as I'm rather attached to my head...

 

Unfortunately, I haven't done much in the way of physics, so all I can draw on is my GCSE... Ideally, I'd like to be able to press a button on a radio-handset which will set off a spark inside the chamber.

 

So far, I've tried:

- Dismantling transformers (battery chargers for old phones/portable vaccuum cleaners) but I've found that they dont spark. However, they are plenty of fun for shocking your friends.

- Dismantling Peizo-electric ignitor & wiring them up to 15ft of wire - No spark (I'm guessing too much resistance in wires)

- Using thread to tie down a Peizo-ignitor and pulling a length of string to cut the thread... crap if the cannon doesn't go off first time, which it didn't... so I walked over and I pressed the ignitor in to reset it... and it did. (Very smart, yes I know).

 

Were Tazers legal here in the UK I'd gladly use one of them, however they're hard to come by. And they're not legal in France, Italy, or NZ. I've thought about cattle prods, however they don't actually spark, they just shock, kinda like the transformers.

 

I've considered trying to get the transformer directly from electronics stores, but I don't really know exactly what I'm looking for, or where to find it.

 

Latest plan: Spark Plug & Coil from an engine. I'd like to keep costs low so this wasn't my first option. That and the parts aren't so easy to come by, AND it sounds rather more complicated. I have no idea where to go to get the parts, or what to do with them.

 

Past actually getting the Spark, I also need to get it activated by remote. I was hoping to buy a cheap R/C car and hack it to pieces, or going to an electronics store to get a DIY R/C kit... and by hoping, I mean haven't looked into this at all.

 

Its not essential to run them off 9V batteries, I just assumed that they'd be the most convenient power source.

 

Any suggestions???

[concrete_hed]

For a remote control, the easiest way would to use an infrared diode and receiver. The small current that will pass through the reciever will be enough to turn a NPN transistor on that will then turn a small relay on, there will be a capacitor in series with the relay so that the relay will swith off shortly after it is switched on. When the relay is switched on it will allow a very large current to travel from a charged capacitor (or another power source) to a coil, and then when that capacitor is automatically switched off it will cause a small spark to run accross the spark gap.

 

This is my theory anyway, there are some limitations such as the infrared reciever which may be affected by the sun and other hot objects. And my spark gap, the spark may run between the tiny terminals inside the relay instead of where i want it to go. Im not entirely sure if my idea would work but i have tried running it through some electronic circuit simulators and it seams to work fine. But without me showing a diagram it is probly difficult to picture what i just explained.

 

Im not sure if that helps but im still learning too

[Mole]

I'm not Dead keen on Infra red, as I'll probably be using the Cannon in broad daylight, from quite a distance. I've found remotes to stop functioning from the other side of the room, let alone the other side of a garden, In broad daylight...

 

But that does sound really good and simple Just to clarify: The actual Ignition circuit involves: Power source, Capacitor, Spark Gap, and relay switch. The ignition circuit is controlled by the relay switch, which is controlled & powered by the I.R. receptor. Right?

 

Great... Now where can I get the components I need, how much would they cost, and what sort of capacitor/relay switch do I need??? I'd imagine the capacitor would say its... capacity on the label... but relay switches & I.R. controlls???

[concrete_hed]

As i said earlier im not entirely sure if my idea will work, but it does work when i run it through Crocodile Clips (an electric circuit simulator). For the circuit i used in the simulation:

 

1000uF capacitor

a push button swith

9 volt battery

a relay (the relay will have to be able to swith over with 9volts)

 

that is just for the circuit to turn the relay on to allow a larger current to pass through the relay. For the ignition circuit i used

 

100ohm resistor (i would recomend building your own resistor so it is able to handle the current)

10mH inductor

12 volt battery

 

If you live in New Zealand like me then you will be able to everything you need from DickSmith, if not, there ought to be an electronics shop near you that sells these components. The most expensive parts would be the relay and the battery, you would probably have to make your own inductor out of magnet wire which could also be costly depending on how many turns and the guage of the wire u want. The rest of the stuff (switches, capacitors) can be bought for less than $1. Over all it would cost $25 (NZD) for the ignition circuit (relay, swith, capacitor, inductor, resistor, wire) (excluding batteries).

 

Again i say, im no genius, im still learning how to do this stuff. If you would like to see a diagram of the circuit, please email concrete_hed@hotmail.com.

[Mole]

Damnit... I was in NZ for 5 months... Just got back in may. I think I know a Similar store Called maples here in the UK... and by think I mean hope.

 

Hangon... In the Relay circuit, what's the capacitor for??? Isn't the relay circuit just power source, relay switch, and on switch??? (If using IR, then powersource and on swich are same... like you said) And the Ignition circuit the Capacitor and power source??? What do you need the resistor for?

 

Thanks for this btw.

[concrete_hed]

As i said earlier it is probly hard to picture what im talking about without showing u a diagram. Basically, the capacitor is used when the power is turned on by the infrared, it turns on the relay and at the same time the capacitor is charing, it will charge for about a second (depending on size of capacitor) and then when it is fully charged it will stop the current flowing to the relay therefore the relay will switch back to its original position.

 

The reason i have designed it like this is because the spark only happens when the powersource is disconnected from the inductor, and this was the easiet way i could think of without using more complicated circuits. You could just use a normal switch instead of the relay, you would have to switch it on and then off quickly to get the spark, but that wouldnt be remote. this way all you have to do is press a button to turn the relay on, and then the relay will switch itself off automatically, giving you a spark. And the other reason why i used a relay was because that relays can handle high voltages and large currents that you would get from the spark, transistors cannot.

 

Ok i finally figured out how to attach images. If you can understand the circuit below then good on ya because im not very good at designing stuff. When i run it through the simulator, the spark gap and the relay blow up. But when i look at the stats of the process afterwards, it tells me that the spark gap reached a voltage of 1.2e+017volts. My guessing tells me that the relay should still be useable after a shot, as long as you dont use too much power. If you can think of any ways to improve me circuit then please help me.

[Mole]

BLIMEY!!! THANKS!!! 1.2e17??? If I'm not mistaken... thats 120 000 000 000 000 000. If You can easily produce that from a few 9V batteries and components from an electronics store... I'll be prepared to set up a small cult worshipping your mastery of electronics.

 

Ohyeah, and I love the Safety angle... with the discharging the capacitor... I'd never have thought of that.

 

Right... I really hope those red & blue things aren't important... because I really don't get their significance.

 

Now, That really big Green thing, I'm guessing is an electromagnet to close the spark circuit??? (See Purple ???'s) And I'm assuming the Thing in the circle with *capacitor?* written is the capacitor... Same for the Electrmagnet in the sparker circuit...

 

And... what's the purpose of the resistor marked "100"??? The rest I can ... roughly grasp.

[concrete_hed]

first of all the big green thing is a relay. when current is passed through it it creates an electromagnetic switch to be switched on, when the current is removed then the switch will go back to its original position.

 

The thing right next to the spark gap is an inductor (coil). This creates an electromagnetic field as current is applied to it (when the relay is switched on), when the current is released (relay is switched off), the electromagnetic field collapses all at once, as the relay switch has been turned off the electrons will have no where to go so they will jump accross the spark gap. Some of the electrons may jump accross the gap in the relay, but since the spark gap is closer, most of them will go accross there. This one in this circuit is 10mh, i dont know how many coils that one is but there are other sites on the internet that u can use to calculate the amount of coils and guage of wire to use for building coils. It doesnt have to be exactly 10mh, could be more, could be less.

 

The 100ohm resistor is used to stop the circuit blowing up as soon as the relay is switched on. If you ever try connecting a 12volt battery negative and positive terminals together without an energy user inbetween, it will make lots of sparks and the battery heats up and could be damaged. Using ohms law i calculated that with 12 volts of power and 100 ohms resistance this should create a current flow of 0.12 amps which should be a safe current.

 

Yes that thing in the circle is the capacitor. And just ignore the red and blue things, they are just part of the simulation program i used to monitor the voltage and stuff.

 

although the circuit says that it creates 120 000 000 000 000 000volts, i dont think that the simulator is correct because that many volts is FREAKIN MASSIVE, even tesla coils and tazers arent that high voltage.

 

If you want to try Crocodile Clips you may like to download it, its fun and it might help you. If you are going to build one of these dont blame me if it doesnt work, im not a genius you may want to ask someone else on what they think. And make sure that you use a relay that will switch over with around 9 - 12 volts, otherwise it wont work at all.

[Mole]

Smashing. You've been loads of help.

 

Yeah, Tazers start at 50,000 V and the most I've seen is a million... as for 120 trillion... no... just no.

 

Crocodile clips you say??? Hmm... I'll Look into that.

 

As for short-circuiting batteries... So THATS why they got so warm!!! I was wondering :s

 

I don't quite get how the coil next to the spark gap works... But I'll take your word on it... after croc-clips.

 

Thanks!!!