SETTING THE TRANSFORMER TO HIGH TAP
All the manufacturers have a transformer setting for locations with "low line voltage".
Low line voltage happens most often in the summer when your game is plugged into a
power line that shares an air conditioner.
The high-tap transformer setting will bump up the solenoid voltages (only, does not
affect light voltages) about 2 or 3 volts. This gives your pop bumpers, kickers, and
flippers a bit of extra power. Not a ton, but just a bit. Don't worry, you won't burn out
coils with this setting. I set most of my EM games to high-tap and it gives them just a bit
more punch. But again, it's personal preference and what you like.
High-tap does NOT effect the lights. High-tap ONLY effects the solenoid voltages. The 6
volts used for the bulbs aren't effected. They use a separate winding on the transformer.
Well, this isn't completely true. If your Gottlieb game has a light feature like "Last Ball In
Play", high-tap could roast that particular bulb (only). This happens because some
feature lights run off the 30 volt solenoid voltage and use a 75 ohm 10 watt resistor to
knock the 30 volt current down for 6 volt lamps. If you go to high-tap, you may need to
increase this resistor to 125 ohms. Otherwise those select bulbs (only) will burn too hot.
These lamps can be easily seen on Gottlieb schematics. All the normal 6 volt lamps will
be on the upper left corner. If a lamp is shown on the shematics in the same section as
coils and relays, then there will be a drop-down resistor to limit its lamp current.