HV Potential across air -- how much to create an arc on contact with solution?
Madeinchina, Sat Mar 03 2007, 11:34PM
I am drawing up plans for a (small) pyrotechnics project for a large event in late summer in the Nevada desert. Essentially I will be floating small bubbles filled with H2O (in gaseous form) up into a grid of HV wires. This will be mobile and battery powered, likely motorcycle 12 or 24 volt. I have not been involved in any HV projects before, but I am quite familiar with precautions from projects running on mains current.
I am looking at a basic flyback design, but I noticed a lot of them are high power enough to sustain an arc. I only want an arc when the bubbles float into the grid.
What I am hoping for is to get an idea of a target kV number in my circuit design and a related gap size between the grid wires to ensure reliable ignitions and minimal shorts. Also, will the use of a high amperage lead-acid battery be a concern as to the final amperage of the HV output? Or does the flyback have internal limitations? Thanks in advance!!
Re: HV Potential across air -- how much to create an arc on contact with solution?
ragnar, Sun Mar 04 2007, 04:27AM
Just about any flyback and any driver with any power source will do.
You position the electrodes so they are just out of arcing range, and I think it's almost guaranteed that if moist bubbles go anywhere near/between the wires (depending on your arrangement of AC/DC) that you'll get an arc and successful ignition.
Re: HV Potential across air -- how much to create an arc on contact with solution?
Sulaiman, Sun Mar 04 2007, 08:11AM
You could use a battery-powered bug killer/zapper circuit
and make your own grid.
Probably easiest to just buy one and 'modify' it.
Re: HV Potential across air -- how much to create an arc on contact with solution?
ragnar, Sun Mar 04 2007, 08:50AM
Methinks it would be problematic without a custom grid and a 'proper' (20kV+) high voltage supply -- if you encounter the issue of the bubble bursting before the circuit is completed through an arc... ignition won't occur..?
Re: HV Potential across air -- how much to create an arc on contact with solution?
Steve Conner, Sun Mar 04 2007, 11:30AM
This sounds like the kind of thing that is best solved by doing a load of fun experiments with different wire spacings and HV sources. I'm surprised you guys even need an excuse to start zapping hydrogen filled bubbles with flybacks. Personally I'd be looking at getting the grid to spray corona from points all over its surface, and hope the corona would ignite the hydrogen even if the bubbles didn't burst in the right places to start arcs.
Is it Burning Man? It would be neat to think that 4hv had a hand in something that gets shown there.
Re: HV Potential across air -- how much to create an arc on contact with solution?
Nik, Mon Mar 05 2007, 01:43AM
Do you mean soap bubbles filled with hydrogen and oxygen or just cloud/bubbles in open air? If it's a soap bubble then pretty much any flyback will ignight the bubble as long as it touches two of the wired, if it is clouds/bubbles in open air I dont know how that woudl be done.
Have fun.