How the Gottlieb fluorescent displays work
The tube works like a vacuum tube: the AC-heated filament is the cathode, and a segment lights when its anode and the digit grid are taken positive. Because the filament swings negative each half cycle, a small positive DC offset is added to it so a grounded grid or anode really stays dark.
Systems
Related tips
- How the System 80 fluorescent displays light
- Measuring voltages on a display board
- Meter check of the display board 7432
- Checking the +60 V filter caps on a display board
- Replacing a display glass tube
- Never plug displays with the power on
- Which CPU chips run the displays
- Reviving a faded Futaba display
Source: Troubleshooting Gottlieb Displays (On Target technical newsletter, vol. 3 issue 7, 1982), Gottlieb "On Target"