I would like to build a really small carbon arc light, as small and cheap as possible just to experiment with this ancient technology. I was planning on using the carbon rods from some AA or AAA carbon zinc cells that I have laying around. If it works then I may one day build a larger one.
I’m not comfortable “playing” with AC electricity, although I do have a 1kW 48VDC transformer and some constant current buck converters.
My questions are:
What’s a rough approximation of the minimum voltage and current needed to be able to see the light against a wall in a dark room?
Do I really need welding goggles to do it safely if I’m only making a “small”, low powered light? At what point in terms of voltage and current would I need to use welding googles?
Could I use something like a steel food can or other household items to make a primitive reflector?
Is there anything else I need to consider or be aware of? I will be doing this outside, well away from anything else flammable.
I don’t know much on the electric side of an arc lamp but I know that it gives off Tons of UV light. You need to contain the arc inside quartz glass otherwise the UV can be pretty bad for your health, especially eyes.
A xenon lamp for projector would make a fun project but it’s not carbon arc.
Even a small arc light will need eye protection as it is about the equivalent of a arc welder as far as light output is concerned, including a lot of UV. Even a small arc is very intense light. In fact a small arc welder power supply might be the way to go for powering your device. For years Harold’s Club here in Reno had a bank of smaller WW2 arc lights that they used on the casino roof to put on a light show to attract the tourists. They searched the world for unused surplus carbon rods designed for their lights to keep them going for years. I had a neighbor who told me about that as he was the casino’s maintenance supervisor for years.
You also need a carbon rods feed mechanism to keep the spacing between the carbon rods correct as they burn away and cover the initial start which requires the rods to touch and then be separated to the correct spacing. All in all this is a fairly complex mechanism if you want any appreciable run time once the arc is struck. I am old enough to remember when old WW2 large search lights were relatively commonly used for advertising to attract attention. Not many still in working condition after 80 years or so.