How the WPC lamp matrix is switched
TIP107 PNP transistors put +18 V on the eight columns and TIP102 NPN transistors ground the eight rows. One column is lit at a time and each comes round about 60 times a second, so all lamps look lit.
Systems
Related tips
- How the WPC lamp matrix works
- WPC lamp matrix and GI driver parts
- A lamp column or row stays on all the time
- A row or column of lamps stuck on and too bright
- Which transistor drives which WPC solenoid and lamp circuits
- BR1 (D11-D14 on WPC-95) and the board around it scorched
- A lamp row very bright or dead
- Where the WPC coil and lamp drivers sit
Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer