Hi,
No problem at all ? If you null it even that will reduce to zero, but be careful. It's not always straightforward measuring such things, and I would again use a low pass filter on the output to get a "truer" reading.
Does your meter actually read 0.000volts with the probes shorted ? If you swap the meter leads round does it show -0.1mv or something different
No problem at all ? If you null it even that will reduce to zero, but be careful. It's not always straightforward measuring such things, and I would again use a low pass filter on the output to get a "truer" reading.
Does your meter actually read 0.000volts with the probes shorted ? If you swap the meter leads round does it show -0.1mv or something different
Mad thoughts as you do, not just from todays posts but going way back.
Regarding power amps -- have the error signal fed to a sample/hold circuit that only operates at switch on for a minute or so and then say every 5 mins after that, just for long enough for a new error voltage to be aquired. Problems, well I suppose if there were significant drift of the offset then each time it corrects that could be audible.
Captain Mainwaring again " Your getting into the realms of fantasy now Mooly "
Next ? (Back to the preamp now) Use the output of the servo to correct the OPA via it's offset null terminals. That could interesting, perhaps setting a deliberate error up on one pin and correcting via the other, or perhaps some Opto scheme.
But I think with 0.1mv untrimmed we won't bother today.
It's Tea Time -- and not a moment too soon
Regarding power amps -- have the error signal fed to a sample/hold circuit that only operates at switch on for a minute or so and then say every 5 mins after that, just for long enough for a new error voltage to be aquired. Problems, well I suppose if there were significant drift of the offset then each time it corrects that could be audible.
Captain Mainwaring again " Your getting into the realms of fantasy now Mooly "
Next ? (Back to the preamp now) Use the output of the servo to correct the OPA via it's offset null terminals. That could interesting, perhaps setting a deliberate error up on one pin and correcting via the other, or perhaps some Opto scheme.
But I think with 0.1mv untrimmed we won't bother today.
It's Tea Time -- and not a moment too soon
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