Wavelength Electronics WHY5640, Datasheet And Operating Manual

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WHY5640 TEMPERATURE CONTROLLER
Resistor, R
2
, is a fixed resistance value that can be used
to scale or adjust the setpoint voltage, V
IN
, allowing control
above and below the ambient temperature. In most
applications select resistor, R
2
, equal to two times the
desired operating RTD resistance, R
RTD
.
Figure 19 demonstrates an example of how to use an
external voltage setpoint to control a 100 Ω RTD from a
range of 0 Ω to 200 Ω.
Figure 19. Example Using a 100 Ω RTD with External Voltage
Control
Operation with AD590 & LM335 Sensors -
Pins 1, 6, & 7
Use an AD590 and LM335 Sensor to operate the WHY5640
controller. Figure 20 illustrates how to connect the WHY5640
for operation with PTC (Positive Temperature Coefficient)
linear sensors AD590 or LM335. Choose one of the top
circuits (LM335 or AD590 sensor) to use with the bottom
circuit.
Equation 9 illustrates how to determine the setpoint
resistance, R
S
, given a desired operating temperature
measured in Celsius.
Rs = 2R3 [0.5 – (273.15 + T
Celsius
)(1mV / K)] (10)
Resistor, R
3
, is a fixed resistance value that can be used to
scale or adjust the setpoint resistor, R
S
. Select resistor R
3
equal to 10 kΩ for most applications.
Figure 21 demonstrates an example of how to use an
AD590 to control from -50ºC to +150ºC.
Figure 22 illustrates the setpoint resistance, V
IN
, versus
AD590 temperature for the example in Figure 21 .
+0.5V
SENSOR BRIDGE AMPLIFIER
R3
RS
1
7 6
SETPOINT
RESISTOR
V
T
= 1 mV/Kelvin
V
DD
LM335
10 mV/Kelvin
+V
T
-V
T
AGND
1/2LM358
SENS ERR
WHY5640
1 kΩ
9 kΩ
1 kΩ
V
DD
1 kΩ
AD590
1 µA/Kelvin
+V
T
-V
T
-V
T
+V
T
OR
Figure 20. AD590 & LM335 Operation Circuit
Figure 21. Example Using AD590 Sensor
Figure 22. Example Setpoint Resistance vs. AD590
Temperature
R
S
1 7 6
V
T
= 1 mV/Kelvin
V
DD
1 k Ω
AD590
1 µ A/Kelvin
AGND SENS ERR
1/2 LM358
1.5 k Ω
10 k Ω
+0.5 V
SENSOR BRIDGE AMPLIFIER
WHY5640
SETPOINT
RESISTOR
5 kΩ TRIMPOT
+0.5V
SENSOR BRIDGE AMPLIFIER
R
RTD
1
7 6
100 Ω RTD
V
IN
+
-
1/2LM358
AGND
SENS
ERR
WHY5640
200 Ω
5
6
4
3
2
1
-50 0 50 100 150
0
Temperature (Celsius)
S
et
po
in
t R
es
is
ta
nc
e
(k
oh
m
s)
RS Setpoint Resistor