Changeset 17234

Timestamp:

10/17/13 15:17:30 (11 years ago)

Author:

tbretz

Message:

So far the assumption was that the precise one is the DAC, but (most probably) because some current is lost into the OpAMP, the really precise device is the ADC. Consequently, the inverse calibration factor applies to I9 and not to I8.

File:

• trunk/FACT++/src/feedback.cc (modified) (1 diff)

trunk/FACT++/src/feedback.cc

@@ -504 +504 @@
 
             // Current through ~100 Ohm measurement resistor
-            const double I8 = (adc-fCalibDeltaI[i])*fCalibR8[i]/100;
+            //const double I8 = (adc-fCalibDeltaI[i])*fCalibR8[i]/100;
+            const double I8 = adc-fCalibDeltaI[i];
 
             // Current through calibration resistors (R9)
-                // This is uncalibrated, biut since the corresponding calibrated
+            // This is uncalibrated, but since the corresponding calibrated
             // value I8 is subtracted, the difference should yield a correct value
             const double I9 = fBiasDac[i] * (1e-3/4096);//U9/R9;   [A]
 
             // Current in R4/R5 branch
-            const double Iout = I8 - I9;//I8>I9 ? I8 - I9 : 0;
+            //const double Iout = I8 - I9;//I8>I9 ? I8 - I9 : 0;
+            const double Iout = I8 - I9*100/fCalibR8[i];//I8>I9 ? I8 - I9 : 0;
 
             // Applied voltage at calibration resistors, according to biasctrl