Electronic Circuits and Projects Forum

Originally Posted by Marseyus

Example: I have two circuits each with a spark gap.Circuit one is 1,000 volts at 10 amps and circuit two is 1,000 volts with 100 amps.

At that kind of POWER, about the only difference would be how fast the electrodes MELT?

And where could you possibly get 1000 volts at 100 Amps?
That 100,000 Watts.

An Average home is only 220 volts at 100 Amps, that is just 22,000 watts.

Are your sure your not talking about 10mA and 100mA?

Brightness has as much to do with the Electrodes as the Current.
CARBON Electrodes (Usually Copper Coated) are used in BRIGHT Search Lamps.

Originally Posted by Marseyus

Clarification: As I stated earlier the numbers used were simply for even numbers. The project itself may one day involve voltages and amperage that high, if my initial project sparks my interest (no pun intended). The question is still if I'm correct in assuming that circuit two would have a brighter arc than circuit one.

Well a High Amperage is Good, you don't need that high of Voltage.

An Electric Welder puts out High Amperage at a Much Lower Voltage (25 to 50 Volts) and with CARBON Electrodes, it will produce a Very BRIGHT LIGHT.

Increasing the Amperage by 10 Times, Will make it a Little Brighter, But more likely, Just a LOT HOTTER Spark. Increasing the Voltage will give a Wider Gap, But more likely just result in Burning up the Electrodes FASTER.
A Good Reflector, Like on Spot or Search lamps will help Concentrate the White Light from CARBON Electrodes.

However, with Carbon Electrodes, you need a Mechanical Feed, to Maintain a Good GAP on the Electrodes.

Do a Search on "Carbon Arc Lamps" (AKA: "Search Lights".)

Might be helpful to you.

carbon arc lamps use a solenoid-like device for mechanical feed of one of the rods. if the arc begins to weaken because of the electrode eroding, the voltage goes up across the electrodes. the coil is in parallel with the electrodes. as the voltage goes up, the solenoid pulls in, pulling the electrodes closer together. once the voltage begins to drop off again, the solenoid stops moving at a point where equilibrium is maintained.. this keeps the arc stable, while feeding the electrodes. once the electrodes erode past a certain point, the solenoid reaches a mechanical stop, and since it can't feed anymore, the arc goes out. i have the description and a drawing of this device in an old applied physics textbook, but my flatbed scanner bit the dust a couple of weeks ago. i also seem to remember that the carbon rods have some kind of mineral in the core that makes the white light even brighter than just the carbon alone (possibly some thorium salts or other metallic salt that emits a bright spectrum when heated). when i was a teenager i played around with pieces of graphite from pencils to make a small arc lamp. it kinda-sorta worked, except i didn't have the parts for the solenoid device, so it would work for a little bit and go out.

also, a safety note: be aware that large amounts of carbon dioxide AND carbon MONOXIDE are produced by an arc lamp. these devices need plenty of ventilation. also, the light from one of these (even using pencil graphite) is very intense and contains a lot of ultraviolet light. and you should have some kind of eye protection like welder's goggles. sunglasses are NOT sufficient.