Miniature Lamp Resistance

http://en.wikipedia.org/wiki/Pachinko

damn, you're good! thanks

If the lamps are wired in parallel, they'd all use 9 volts. If they're wired in series (unlikely but possible), divide the 9 volts by the number of lamps in the series to get the voltage drop per lamp. Either way, however, you also want to get lamps designed for the same wattage, so just saying 9 Volts, or whatever, is probably not enough.

If you still aren't sure of the voltage, take a working lamp and try to drive it with a 9 volt battery. If it lights up properly, it's a 9 V lamp. If it's super-bright or flashes and burns out like a camera flashbulb, it was rated for far less than 9 V.

You might find the lamp code printed on the base of the lamp.

You can try reading the resistance. Since P = V²/R, then R = V²/P, so if the lamps are 9V lamps rated at 10 Watts (for example), the resistance would be 8.1 ohms. You can try this to determine the wattage, but the resistance will increase over time (and the actual wattage and brightness will drop).

For a really longlife and a lower price, go for 12 volt lamps of the same physical size.....the wattage will be quite close if not perfect when in the same size glass envelope.....

Using a slightly higher voltage will really help if when played, the machines are vibrated, even slightly....thats not good for full brightness filaments....

Its possible that some indicator bulbs bases can be bought nowadays with LEDs inside........but I have no idea which, sorry.....they are more resistant to vibration.

I would forget the bulbs ad switch to LED's They cost less, do not burn out and use far less power to operate.

Likely all are true, however there are several critical concerns the OP should consider before going with switching to LED lighting. It is not likely an LED will work with the existing power supply hardware. This will therefore require additional circuitry between LED and the power supply. To be honest, not a lot of circuitry or complicated circuitry but additional circuitry all the same. Since this is an "overhaul", there maybe value lost by not restoring with original equivalent components.

I had an older pachinco machind that used a 6 volt dry cell lamp battery