TE Technology TC-24-12 - Manual (Page 10)

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13.2 Set the Integral Rate Potentiometer (R16) to zero by adjusting it to its maximum counter-
clockwise position (voltage at TP5 = 0.0V). This turns off the integral function.
13.3 Set the Proportional Bandwidth Potentiometer (R14) to its maximum clockwise position
(voltage at TP4 = 5.0 V).
13.4 Adjust the Set-Temperature Potentiometer (R13) to the desired temperature using TP3 and
the voltage versus Set-Temperature graph/data as a guide.
13.5 Adjust the Proportional Bandwidth Potentiometer counter-clockwise until a small,
sustained temperature oscillation is observed. (You can adjust in initial increments of 1 V,
or 5 turns. Then, once an initial oscillation is observed, adjust the potentiometer clockwise
until the oscillations are barely detectable).
13.6 Record the voltage at the Proportional Bandwidth Potentiometer (at TP4) to sustain the
temperature oscillation.
_________________________ Volts
13.7 The time that it takes to go from one peak temperature to the next peak temperature is the
natural period. Record the time of the natural period in minutes.
_________________________ Minutes
13.8 Measuring the voltage at TP4, turn the Proportional Bandwidth Potentiometer clockwise
until the voltage recorded in section 12.6 is doubled (this now doubles the bandwidth.) If
the voltage recorded in section 12.6 is greater than 2.5 V, then adjust the Proportional
Bandwidth Potentiometer until the voltage is 5.0 V.
13.9 Set the controller Integral Rate variable (the number of repeats per minute) to the inverse,
or reciprocal, of the natural period recorded in section 12.7 by adjusting R16. There are
0.102 repeats per minute per turn of R16. Using the voltage at TP5 as a guide, the Integral
Rate can be set as follows: voltage at TP5 = 5/2.55 * (reciprocal of natural period
recorded in section 12.7). See the “Integral Rate as a Function of Voltage” graph for
further reference.
13.10 These Proportional and Integral settings are approximate settings and may need further
minor adjustments. Record the final voltages used on the Proportional Bandwidth
Potentiometer and Integral Rate Potentiometer.
Final voltage on the Proportional Bandwidth Potentiometer (TP4)
=__________________ Volts.
Final voltage on the Integral Rate Potentiometer (TP5) =__________________ Volts.
Additional systems with the same thermodynamic properties will operate using the
Potentiometer settings listed above.
Tuning Example: