When we discharge the capacitor in our Integrator we want it really discharged. Some capacitors do better than others for reasons that are not clear.
Mylar Capacitors were used in BattleZone, but did not work very well in Star Wars, which had a faster drawing speed. The capacitors that worked the best for us in Star Wars were Polycarbonate Capacitors.
Polycarbonate is a clear and colorless amorphous thermoplastic notable for its high impact resistance. In addition to its use in capacitors it is used in glazing, safety shields, and CDs. (An excellent Web site for the properties of materials is http://www.goodfellow.com/.)
Polystyrene capacitors are also considered high quality capacitors but they worked poorly in the Integrator.
The properties of polystyrene are similar to polycarbonate but for reasons that are unknown the polystyrene capacitors exhibited problems that appear to be the result of charge redistribution.
Finally, the issues of Leakage, Inductance, and Series Resistance are not confined to the capacitor itself.
They can also be caused by circuit design and layout. The circuit layout can also screw things up if there is crosstalk from another signal trace.
It doesn't always end there, either. One time I was asked to look at a prototype AVG board for another project which was producing really nasty vectors. The digital circuitry had been checked and was ok. We ended up unsoldering all the parts in the Integrator and connecting them together off the board in the air. That fixed the problem and we concluded that the material used in the PC Board was contaminated. The next run of prototype boards was ok.
« Older “It’s no better since Anita Hill because we don’t... | The Girl In The Yellow Dress Newer »