[time-nuts] Question about SoundCard stability?

[Bill Hawkins]

Group,

The primary controller issue is too little reset because the
integrating capacitor is too small or bad. After that comes
too much gain.

Power lead resistance would reduce the gain. Conversely, high
voltage would increase gain.

Don't think extra insulation is a stability issue, unless it's
between the heater and the sensor.

One other thing - dead time will destabilize the control loop,
when there's too much delay between the heater's heat being
sensed by the thermistor. This is usually a location problem.

Bill Hawkins

(50 years in industrial process control)

-----Original Message-----
From: Bob Camp
Sent: Wednesday, October 13, 2010 5:58 AM

Hi

Controller cycling is often a result of one of two things:

1) Resistance in the power lead 
2) Extra insulation / dead air
3) Internal controller issues

There are a few other possibilities, but they are remote enough that
you are unlikely to ever come across them. There's no advantage to
building a controller that's cycling. It was more likely a bug than
a feature.

Bob