Let me apologize in advance for the long winded explanation... skip to the end if you want a TLDR summary.
Game in question is a Genco "Criss-Cross-A-Lite"-- a 1930's vintage mechanical game, with electronic scoring, originally powered by a battery. When I acquired the machine I installed a transformer for reliability (and to avoid having to take the whole dang machine apart any time the battery needed to be changed!). The circuit is on for ~3 minutes, after which the game shuts off and the lights go out (by design).
The game originally used #40 bulbs. The bulbs screwed into a a thin piece of sheet steel that ran the width of the machine-- they were very poorly grounded and would flicker all the time. I went so far as to solder a wire to the bulb, and solder the other end of it to ground... and soldered the tip of the bulb to to a wire that I soldered to the original connectors. It wasn't pretty.
I searched for new #40 bulb holders, and the only ones I could find were like this: https://www.amazon.com/Sci-Supply-LC20505-10B-Bulb-Holder-Socket/dp/B077BWFDYG. These will not fit behind the backglass.
So... I removed all of the bulbs and installed #555 sockets and bulbs. Individually, the bulbs work fine, but they seem to be much more sensitive to voltage than their incandescent counterparts, and once 3 or more of them are lit, the light drops off dramatically. I'm a bit stumped about what I can do to compensate-- I know, I know... I could switch incandescent 555s in, but I'd prefer to not generate that heat if I don't have to.
Would a capacitor for each bulb solve this? And if so, how would I go about calculating the value? I(t) = C dv/dt... so if I'm thinking about this right, and approximate .1 amp draw for each bulb (it's probably smaller than that) it would be .1 * 180 (seconds)/ 6 (volts)... so a 3 farad (!) capacitor for each? That doesn't seem right.
TLDR: Experiencing voltage drop and LEDs aren't working. Can't figure out a reasonable solution.
