Adaptive® JUNIOR – Technical and HMI User Guide
REV 1.04
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Setpoint 0 to 100 % of full input voltage
Output mode
0%
50%
100%
(TEC) -ve & +ve
Full negative
output
0v
Full positive output
(Other) +ve only
Zero output
50% of positive
output
100 % of positive
output
(Other) TRIAC
0% duty cycle
50% duty cycle
100 % duty cycle
Table 6 Output drive polarity based on output mode and drive level
4.5.2.
Thermostat Control Mode
This mode works in the same way that a mechanical thermostat would
except that it has programmable hysteresis and dead band controls. It
maintains the temperature measured on sensor D’s input to the setpoint
entered using the values entered for hysteresis and dead band.
Hysteresis is used in systems to stop the control from continually
switching back and forth when the temperature is close to the setpoint.
In a mechanical system this reduces wear and tear of the parts and also
energy. Wear is less of a problem in modern systems but energy and
switching are still important.
Dead-band is similar to hysteresis, but where hysteresis is used to prevent the output switching unnecessarily, dead-
band switches off the output completely while the temperature is within its window.
The switching on point for the heater is (setpoint – dead-band – hysteresis) and for switching on the cooler (setpoint
+ dead-band + hysteresis). The heater switches off at (setpoint – dead-band) and the cooler switches off at (setpoint
+ dead-band).
Examples of typical output switching for both these modes is shown in the diagram below. Note to make the
switching points clearer in the diagram below, the heater will always be on below 23°C and the cooler always on
above 27°C.
Figure 16 Example configuration shown hysteresis and dead-band for bidirectional drive
23
25
27
Setpoint
°C
2°C hysteresis without dead-band
23
27
25
24
26
Setpoint
°C
1°C hysteresis with 1°C dead-band
Heater on
Heater switch on/off
Cooler on
Cooler switch on/off
Figure 15 Thermostat operating mode
Figure 14 Selecting the output drive method when
the control mode is OFF
