Triacs switch AC lamps

Unlike an SCR, a triac can switch AC, which is why WPC uses triacs to switch and dim the general illumination strings.

Systems

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

Related tips

• Checking GI triacs with the game on
• Testing a lamp diode
• Replacement GI triacs
• How the WPC lamp matrix works
• Testing lamp-row drivers with a test lamp
• Testing lamp-column drivers with a test lamp
• Bench testing a GI triac with a 9 V battery
• The three WPC lamp circuits

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