hi
what will be the best transformer to use to create a spark 5mm-10mm in length?
input=9v
will one from a prank gum
http://electronics.pickegg.com/Electronics-image/2010-10/Electric-Shock-Chewing-Gum-Prank-Toy-6342221662675000005.jpg
and will it be lethal?
What is the arduino going to be do-ing.
You need DC for decent spark lengths, not AC as they quench on every zero-crossing.
You also need to be aware of the risks and need to limit the maximum current to something
less likely to kill. If not sure assume lethal shocks are possible and take the necessary precautions.
RF sparks are another possibility (as used in Tesla spheres/coils), and they have the advantage
of not penetrating far but burning at the surface due to the skin effect. Yes RF is AC, but too
fast for the spark to quench (the ions don't have time to recombine).
But remember safety is paramount - it only takes one mistake with high power high voltage
supply... If in doubt: don't.
I remember that prank from the 1970s, the "shock" was from the snapping noise made by a spring that flipped over when a stick of gum was pulled out.
I don't see how you can easily interface it to an Arduino.
I forgot to say that I don't think the item in the link will be lethal.
From what I can remember, this device worked about as well as the X-Ray spectacles that you could buy.
JohnLincoln the gum packets have batteries and a small pull up transformer inside.
will i be able to create a spark using a 9v battery and this small pull up transformer.
question about transformers
is it only the volts that change or amps and volts that change?
help9meh:
JohnLincoln the gum packets have batteries and a small pull up transformer inside.
will i be able to create a spark using a 9v battery and this small pull up transformer.question about transformers
is it only the volts that change or amps and volts that change?
volts out * amps out < volts in * amps in
Voltsamps out can't be higher than voltsamps in, otherwise you'd be creating energy out of nothing, and since efficiency isn't 100%, the output power (volts * amps) will be lower than input.
Seems like they have updated this prank, with the latest technology. Perhaps modern X-Ray specs work better too.
what will be the best transformer to use to create a spark 5mm-10mm in length?
The dialectric breakdown voltage for air is 3,000,000 V/m
which can be rearranged to 30000 V/cm (by dividing numerator and denominator by 100)
which tells you that you need at least 30,000 V to get a spark 1 cm in length.
okay...
I'm trying to get something similar than the spark fun cap ignighter but thats retired any thoughts on how i can get one or recreate it?
hi this might be inconvenient but since its looking like i won't get my sparks I've gone for a different way of ignition
nichrome wire for 8$nzs
thanks for your help and possibly saving my life 
I don't think you can get any thing that has both the HV and the current. I got shocked by a 30,000 V neon transformer and all it did was startle me.
Before you go lethal, try a relay and a 9volt battery.
Connect the battery through the normally closed contact to the coil.
The relay turns itself on/off very fast.
The buzzing relay creates high voltage spikes across the coil.
Leo..
Did you follow what Wawa said ?
If you connect the + terminal of the battery to one end of the relay coil and connect the other end of the coil to the COM of the contacts and the N.C. contact to the - battery terminal,, what happens ?
ON because the N.C. contacts are already connected
OFF because as soon as the coil energises the circuit is opened.
ON because the coil de-energized connecting the N.C. contacts again..
etc
et
etc
etc
Don't forget to touch the coil..
sorry im a noob and i have no idea what you said and i dont even know how to use a relay all i want to do is to ignight rubbing alcohol vapour
is the spark fun gap ignighter completely gone?
We're not in the habit of detailing DIY incendiary devices.
???