© 2023
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WHY5640 TEMPERATURE CONTROLLER
STEP 7
ADJUST THE SETPOINT
TEMPERATURE
Adjust the RSET trimpot to change the setpoint temperature.
With the RUN/SET switch in the “SET” position, measure
the resistance between the two test points next to the RSET
trimpot. Adjust the RSET trimpot to change this resistance
to the resistance value of the thermistor at the desired
operating temperature. Once the RSET resistance is set to
the desired level, return the RUN/SET switch to the “RUN”
position.
shows the location of the RUN/SET
switch and test points.
STEP 8
ENABLING AND DISABLING THE
OUTPUT CURRENT
Enable and disable the WHY5640 output current using the
onboard toggle switch. The output is enabled when the
green ON LED indicator is lit.
NOTE: Before enabling the output, make sure the
RUN/SET switch is set to the “RUN” position. When
enabled with this switch in the “SET” position, the
controller will run at the cooling current limit regardless
of the temperature setpoint, which can cause damage to
the controller or your thermal load.
STEP 9
MONITOR SETPOINT AND ACTUAL
TEMPERATURE VOLTAGES
Use VM1 and VM2 to monitor voltages referenced to the
COMMON terminal of the setpoint temperature and the
actual temperature. The input connector includes three lines
for externally monitoring the WHY5640 setpoint resistance
and the actual temperature sensor resistance levels by
monitor voltages produced by the sensor bridge circuit. By
monitoring VM1 and VM2, you can calculate the thermistor
resistance using the following equation.
R
T
=
(
VM2-VM1
)
R
SET
(7)
VM1
