Linear response

[Kevin Weddle]

Most designs employ a large number of components and they generate a lot of noise. But error correction is linear in most cases. If a circuit is going to incorporate a microprocessor, why are smaller circuits limited to simple, linear error correction? A voltage regulator IC, a phase lock loop, an opamp circuit or any other feedback circuit never seems to be logic controlled.

 

[audioguru2]

Logic control is on and off. If it detects that the output voltage is too low then it can switch on full power until the voltage is high enough, then switch off. The output will be continuous waves of voltages.

A linear error correction circuit has an opamp as its error correction amplifier that has a very high voltage gain and makes subtle or drastic corrections. The opamp has a small delay which causes the output voltage to have undershoot and overshoot but is stable and accurate for most of the time.

 

[Kevin Weddle]

I don't believe linear control is unreliable. But a signal that is produced by logic control can poroduce a more time sensitive response. Microprocessors generate at the the nanosecond. So as far as audio goes, it's much more of a higher frequency than that.

Maybe a high frequency expert can explain as to why a high a frequency circuit can't be used in lower frequency applications.

 

[audioguru2]

I do not understand what you are talking about.

 

[Hero999]

Yes, you seem to be talking nonsense Kevin.

How about posting a schematic so we know what you're on about?

 

[Silent Jack]

Perhaps he is seeking to remove noise from what he feels is an overly elaborate circuit by using a microprocessor which, theoretically would be able to smooth things out by responding more quickly.  Much like generators in cars were replaced by alternators in 120 degree phase to smooth out the fluctuations.  Just a thought.

 

[Kevin Weddle]

An opamp can use a thyristor in it's feedback to limit gain. If the error correcting device is at a high enough frequency to detect an unwanted change in the input signal, the gain can be limited. If your going to use high speed logic devices in a circuit anyways, why not utilize them more?