The three WPC lamp circuits

General illumination is five strings of 6.3 V AC bulbs switched and dimmed by triacs. Flashers are 12 V bulbs run from +20 V DC through coil-type drivers. The lamp matrix runs up to 64 6.3 V bulbs from +18 V (higher because each lamp is only lit part of the time) and has electronic short protection.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)

Related tips

• How the WPC lamp matrix works
• WPC lamp matrix and GI driver parts
• Lamp matrix fuse F114 (F106 on WPC-95) keeps blowing
• Testing lamp-row drivers with a test lamp
• Testing lamp-column drivers with a test lamp
• An entire lamp row or column is out
• How the lamp matrix drives a bulb
• No lamp matrix lamps light

Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer