Wayne: Even at 19 ohms, a 12 volt source is only going to deliver 632 mA. 7.6 watts. I wouldn't expect any fireworks. Even on my test bench, lighting an automotive bulb didn't produce any unexpected sources of excitement. And that was with a 13.8 volt (19 amp) supply. The small metal contact I held against the carbon DID get a little warm, but my fingerprints are still readable.

Yeah, that kind of sucks the fun out of it. Oh well, plenty of other monkey business to get into.

 

Here y'go Wayne.