This is a photo of a 1938 Stoner "Chubbie" machine.
The playfield lights that are controlled to go off when the playfield bumper is hit have these 50-60 Ohm resistors wired in series with the bulbs.
What is the purpose of these resistors (I think they are old style resistors, they have a wafer of mica inside the wrap length of wire)?
The playfield lights have ~15 volts of power going to them and they are an odd threaded base bulb, I think a #52.
But the controlled backglass bulbs that show the score are #44/47, don't have any resistor and are powered by the usual ~6 volts that these bulbs would normally use.
So why the two different types of bulbs? Why not just use #44/47 bulbs in the whole machine and why the resistors?
Resistors wired in series would just make the bulb dimmer.
Are they trying to give the light circuit more power draw so something else will work better?
Thanks for the help and any other info someone might have about this old machine.