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MESSTEC Power Converter GmbH
Operating Manual
TEC Controller
Document: 10100920OM
Revision: 1.1
Date: 10.10.2019
Page 47/71
above these limits, the transfer function is clipped to min. temperature and
max. temperature respectively.
Advantage:
The relationship between input voltage and temperature
setpoint in between the temperature limits is always the same.
(see basic transfer function).
Disadvantage: The usable adjustment range (potentiometer or voltage source)
may get too tiny for practical purpose.
8.1.2. HW-Setpoint Boundary Mode: Slope Transformation
In this mode, the relationship between the HW-Setpoint-Voltage and the tem-
perature setpoint is still linear but has a different slope than the basic transfer
function. Now a HW-Setpoint-Voltage of 0 V leads to a setpoint of min. tempe-
rature and 5 V lead to a setpoint of max. temperature (see solid red line in fi-
gure 31 below). This means, the complete input voltage range is used.
Fig. 31: Slope transformation mode transfer function
Example (see figure 31 above):
Supposed, min. temperature is set to 20 °C and max. temperature is set to
30 °C by PC-Software then a HW-Setpoint-Voltage between 0 V and 5 V leads
to a temperature setpoint between 20 °C and 30 °C (arrow 1 to 6).
I.E. a voltage of 2,0 V results in a temperature setpoint of 24 °C (arrow 3).