[time-nuts] Making a HP 10811 and similar types better in the real world Part I

Bob Camp lists at rtty.us
Wed Sep 21 22:50:09 UTC 2011


Hi

Actually, overshoot is pretty easy to eliminate on a conventional OCXO by picking a good location for the thermistor. The heater will always run "hot", but the rest of the stuff does not have to.

Bob


On Sep 21, 2011, at 6:37 PM, Magnus Danielson wrote:

> On 09/22/2011 12:30 AM, Chuck Harris wrote:
>> Perry Sandeen wrote:
>>> GM List,
>>> ..............................................................................The
>>> 
>>> ovens are proportionally controlled. On start-up all ovens,
>>> proportional or not,
>>> will have over-shoot. Some more, some less. An inescapable fact of life.
>> 
>> Imagine that the set point is variable, and can be set below the desired
>> temperature. Then imagine that the set point can approach the desired
>> temperature more closely as it gets closer to the desired temperature.
>> 
>> ... And you will have discovered (100 years late) the PID controller.
>> 
>> PID controllers do not have to overshoot the desired temperature. It is
>> not an inescapable fact of life. 30 years ago I was designing PID
>> controllers,
>> with a little microprocessor magic, that could quickly arrive at the set
>> point
>> temperature and never, I repeat, never, exceed that temperature. Someone's
>> internal organs would have become toast if it did.
> 
> Overshot is fairly easy to avoid for a well controlled PID loop simply by setting the damping factor properly.
> 
> PIDs is nice in that you can control loop bandwidth and damping factor fairly well. Overshot properties vs. damping factor is a well researched field and already tabulated before I was born.
> 
> Cheers,
> Magnus
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.




More information about the time-nuts mailing list