Wavelength Electronics WTC3293-14001 User manual

© 2005-2019
WTC3293-14001 BOARD WITH DISPLAY
WTC3293-14400-J
Online Design Tools at
www.teamwavelength.com/support/design-tools/
GENERAL DESCRIPTION:
Simply stable temperature control. Wire your
thermoelectric cooler and thermistor to the
board with the cable provided. Add the
appropriate DC power supply and indicate the
expected voltage on the jumper. With the
output disabled, adjust the on-board 12-turn
trimpot and watch the setpoint temperature
change on the 4-digit display. Switch to Actual
and display your thermistor temperature.
Watch the LED tree to see “over / under
temperature” or “stable at setpoint” status.
Enable the output current and watch the
temperature quickly lock in on the setpoint.
Figure 1
Top View
WTC3243 Thermoelectric Temperature
Controller Board with Display
WTC3293-14001
FEATURES:
• Low noise, maximum temperature stability
commercially available
• Display thermistor temperature directly - no
tables to convert resistance to temperature
• LED indicator shows over temperature,
stable at setpoint, or under temperature
status
• Adjust setpoint with a 12-turn potentiometer
or an external voltage
• Control temperature using a 10 kΩ
thermistor
• Fixed resistors set Proportional Gain,
Integrator Time Constant, and
thermoelectric current limits
• Enable/Disable Output Current Switch
• Includes Output Cable
• Works with a wide range of thermoelectrics
WTC3243 INCLUDED
WEV301 INCLUDED
May, 2014
Pb
RoHS
Compliant
e
Ordering Information
WTC3293-14001
PWRPAK-7V
PWRPAK-9V
PWRPAK-12V
TEC Controller with Display
(WTC3243 & WEV301 included)
7 V / 2.8 A Power Supply
9 V / 3 A Power Supply
12 V / 2.5 A Power Supply
Distributor
[email protected]m
www.amstechnologies-webshop.com

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WTC3293-14001 BOARD WITH DISPLAY
PAGE 2
WTC3293-14400-J
The display is calibrated for a specic 10 kΩ thermistor, the TCS610:
where T is in Kelvin; R is in ohms,
A = 1.1279E-3; B = 2.3429E-4; C = 8.7298E-8
Bias Current is also chosen for this thermistor: 100 µA
Control temperature range for the 10 kΩsensor is 10°C to 50°C.
Fuse: For safety, a 3 A fuse is included on the board. Replacement part number is Littelfuse 297 003
(ATO MINI 3A).
Power supply input jack accepts a 2.5 mm diameter plug.
NOTE: The WTC3293-14001 is now designed to operate with the 7 V, 9 V, and 12 V power supplies. It is a
direct replacement for the WTC3293-14002.
NOTE: It is normal for the voltage regulator to get hot (~60°C). This regulator is located on the right side of
the unit. See Figure 2, below.
QUICK REFERENCE -- CONFIGURATION
1/T = A + B(ln R) + C(ln R)3
Figure 2
Voltage Regulator Location

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WTC3293-14400-J
1. SELECT POWER SUPPLY VOLTAGE and INSTALL JUMPER
The WTC3293-14001 has been designed to operate at one of three discrete voltages: 7V, 9V, or 12V.
The POWER jumper must be installed for the chosen voltage.
To choose the appropriate voltage for your application, use Wavelength’s online Safe Operating Area
(SOA) calculator for Temperature Controllers:
www.teamwavelength.com/support/design-tools/soa-tc-calculator/.
a. On the calculator page, in the Product dropdown menu, click WTC3293-14.
b. In the Max. Heatsink/Enclosure Temperature text box, type the maximum ambient temperature
the controller will experience.
c. In the Limit Current text box, type the limit current setting you will use.
d. In the Load Impedance text box, type the impedance of the thermoelectric (Vmax / Imax).
e. In the Supply Voltage text box, type the power supply voltage you want to use. This number will
be 7, 9, or 12.
f. Click Find SOA Compliance. A graph showing the Safe Operating Limit and the Load Line is
generated. If the calculations are not within the Internal Power Dissipation Safe Operating Area,
reduce the power supply voltage until the conguration stays within the SOA.
Install a jumper indicating which power supply you have selected on the header near the DC input
plug. NOTE: When you plug in the supply, make sure the Enable Switch is OFF. Do not operate with
a voltage less than 7 V.
WHY? The WTC3293-14001 uses the WTC3243 temperature controller, which is designed to drive
currents as high as 2.2 Amps. The resistance of the thermoelectric will create a voltage drop across
the thermoelectric proportional to the current (Voltage = Current x Resistance). The voltage drop
across the WTC3243 will equal the power supply voltage minus the thermoelectric voltage. If the
power dissipated by the WTC3243 is too high (Power = Voltage x Current), the WTC3243 will overheat
and be destroyed.
2. SELECT HEAT AND COOL CURRENT LIMITS
To protect the thermoelectric from over current damage, set the heat and cool current limits as follows.
The standard product is shipped with 2.00 kΩresistors for 0.5 A cooling and heating limits.
Resistors should be 5% metal lm. Carbon resistors will introduce noise and instabilities.
OPERATING THE WTC3293-14001
Table 1
Current Limit Set Resistor vs Maximum Output Current
MAXIMUM OUTPUT
CURRENT (A)
CURRENT LIMIT
RESISTOR (kΩ)
RAor RB
0.0 1.58
0.1 1.66
0.2 1.74
0.3 1.83
0.4 1.92
0.5 2.01
0.6 2.11
0.7 2.22
0.8 2.33
0.9 2.45
1.0 2.58
1.1 2.71
MAXIMUM OUTPUT
CURRENT (A)
CURRENT LIMIT
RESISTOR (kΩ)
RAor RB
1.2 2.86
1.3 3.01
1.4 3.18
1.5 3.36
1.6 3.55
1.7 3.76
1.8 3.98
1.9 4.23
2.0 4.50
2.1 4.79
2.2 5.11

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WTC3293-14400-J
R=
100,000
100
P- 1
[Ω]
( )
( )
P=
100
100,000
RP
+ 1
[Amps / Volts]
OPERATING THE WTC3293-14001, continued
Table 2
Proportional Gain Resistor RP vs Sensor Type
and Thermal Load Speed
Proportional Gain
Resistor, RP
Proportional Gain,
[Amps/Volt]
Sensor Type/
Thermal Load Speed
4.99 kΩ5Thermistor/Fast
Thermistor/Slow24.9 kΩ20
20
100 kΩ50
50
RTD/Fast
RTD/SlowOpen 100
24.9 kΩ
AD590 or LM335/
AD590 or LM335/
Fast
Slow
100 kΩ
To optimize the control loop (minimize overshoot,
settling time, avoid cycling, etc.) change the
control parameters as described below. If the
load doesn’t stabilize, contact the factory for
troubleshooting advice. Resistors should be 5%
metal lm. Carbon resistors will introduce noise
and instabilities.
3. ADJUSTING THE CONTROL LOOP
PROPORTIONAL GAIN
The control loop proportional gain can be
adjusted by inserting an appropriate resistor,
RP, into Control P location to set P from 1 to 100.
(Shown in green in Figure 4.)
Equation 1 demonstrates how to calculate a
value for RPgiven a desired proportional gain.
Equation 2 demonstrates how to calculate the
proportional gain, P, given a value for RP.
Table 2 lists the suggested resistor values for RP
versus sensor type and the ability of the thermal
load to change temperature rapidly.
Equation 1
Calculating RPfrom P
Equation 2
Calculating P From RP
CONTROL
P
I
Figure 4
Control P and Control I Resistor Locations
Figure 3
Current Limit Set Resistor Locations
A
B
Note: If you want a wiring diagram with values,
use the online WTC3243 design calculator.
This can be found at:
www.teamwavelength.com/support/design-tools/wtc-calculator/

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WTC3293-14001 BOARD WITH DISPLAY
PAGE 5
WTC3293-14400-J
( )
RI=
100,000
(1.89) ITC - 1 [Ω]
( )
ITC = (0.53)
100,000
RP
+ 1 [Seconds]
OPERATING THE WTC3293-14001, continued
4. ADJUSTING THE CONTROL LOOP
INTEGRATOR TIME CONSTANT
The control loop integrator time constant can
be adjusted by inserting an appropriate resistor,
RI, into Control I location to set ITC from 0.53 to
4.5 seconds. (Shown in red in Figure 4, prior
page.)
Equation 3 demonstrates how to calculate a
value for RIgiven a desired integrator time
constant. The integrator time constant, ITC,is
measured in seconds.
Equation 4 demonstrates how to calculate the
integrator time constant, ITC, given a value for RI.
Table 3 lists the suggested resistor values for RI
versus sensor type and the ability of the thermal
load to change temperature rapidly.
Overshoot with Small Loads
When using the WTC with small, fast loads, the
unit has a tendency to overshoot by up to 10˚C.
This problem is caused by overcompensation by
the integrator and can be solved by taking the
integrator term out of the system. This can be
done by placing a shorting jumper in the Control
I location.
Table 3
Integrator Time Constant vs Sensor Type and
Thermal Load Speed
Integrator Resistor,
RI
Sensor Type/
Thermal Load Speed
21.4 k3Thermistor/Fast
Thermistor/Slow13.3 k4.5
1
0.53
4.5
RTD/Fast
RTD/Slow
Open
1
AD590 or LM335/
AD590 or LM335/
Fast
Slow
13.3 k
112 k
112 k
Integrator Time
Constant, [Seconds]
Equation 3
Calculating RIfrom ITC
Equation 4
Calculating ITC from RI

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WTC3293-14400-J
5. WIRE OUTPUT CONNECTOR
Connect the Thermoelectric wires to the Red and Black cable wires as shown. If the polarity is reversed,
the system will only heat. Connect the thermistor wires to the Green and White cable wires (polarity is
not important).
Table 4
OUTPUT CABLE wiring for Thermoelectric
Wire Color FunctionPIN #
RED
GREEN
WHITE
BLACK
1
2
3
4
OUTPUT B - Positive TE wire
SENSOR +
SENSOR -
OUTPUT A - Negative TE wire
Table 5
OUTPUT CABLE wiring for Resistive Heater
Wire Color FunctionPIN #
RED
GREEN
WHITE
BLACK
1
2
3
4
OUTPUT B - One side of RH
SENSOR +
SENSOR -
OUTPUT A - NO CONNECT
Connect other side of RH to V+
Change RLIM A to 1.5 kΩto limit the
cooling curent to ZERO.
Resistive Heater operation assumes
NTC sensor.
OPERATING THE WTC3293-14001, continued

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WTC3293-14400-J
7. ADJUST THE SETPOINT TEMPERATURE
The setpoint temperature can be adjusted from 10 to 65°C either by using the onboard 12-turn
potentiometer or an external voltage source.
The VSET wire pads can be used as test points to monitor the potentiometer setting or for connecting
an external voltage source (such as a function generator). If an external voltage source is used, set
the setpoint potentiometer approximately mid-range (1 to 1.5 V). The input voltage range is 0 to 2.5 V
which corresponds to 0 to 25 kΩof thermistor resistance. [Transfer function is 10 kΩ / V.]
8. ENABLE THE OUTPUT CURRENT & MONITOR IN-RANGE STATUS
The switch next to the In-Range indicator enables and disables current through the thermoelectric.
The green LED on the In-Range indicator lights when the actual temperature is within 0.05°C of the
setpoint. If the actual temperature exceeds the setpoint, the upper LED will light. If it is below the
setpoint temperature, the lower LED will light.
6. VIEW THE SETPOINT and ACTUAL TEMPERATURE
The switch next to the setpoint potentiometer determines whether Setpoint or Actual temperature
is displayed. When the setpoint is displayed, the rightmost decimal point is lit. The resistance to
temperature conversion software assumes the thermistor bias current is 100 µA and the thermistor is
characterized by the Steinhart-Hart relationship:
where T is in Kelvin; R is in ohms, A = 1.1279E-3; B = 2.3429E-4; C = 8.7298E-8 (TCS-610)
If another thermistor or bias current is used, the temperature display will not be properly calibrated.
To use another sensor or change the calibration, contact the factory.
1/T = A + B(ln R) + C(ln R)3
Setpoint Potentiometer
Setpoint/Actual
Display Select Switch
In-Range Indicator
Enable/Disable
Switch
OPERATING THE WTC3293-14001, continued

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WTC3293-14400-J
MECHANICAL SPECIFICATIONS
2.25 [57.2]
2.25
[57.2]
2.000
[50.80]
0.125 [3.18]
1.00
[25.4
]
0.625
[15.88]
0.08 [2.0]
0.40
[10.2]
0.115 [2.92]
0.125 [3.18] dia thru 4x
Max height from top side of PCB to fan is 1.50” [38.1 mm]
Standoffs are 0.625” [15.88 mm] tall
Board thickness is 0.60 [15.2” mm]
Allow 0.375” [9.53 mm] clearance from bottom side of PCB for airflow
The WTC3243 connects to the evaluation board by
two 7-pin SIP sockets. The socket manufacturer is
Aries Electronics, PN 25-0513-10.
Dimensions are inches [mm].
All tolerances are ±5%.

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WTC3293-14001 BOARD WITH DISPLAY
PAGE 9
WTC3293-14400-J
REVISION HISTORY
REVISION
REV. E
REV. F
REV. G
REV. H
REV. I
REV. J
DATE
Aug-2005
31-Aug-09
25-May-11
30-Jul-12
25-Jan-13
7-May-14
NOTICE:
The information contained in this document is
subject to change without notice. Wavelength
will not be liable for errors contained herein
or for incidental or consequential damages in
connection with the furnishing, performance, or
use of this material. No part of this document may
be translated to another language without the
prior written consent of Wavelength.
SAFETY:
There are no user serviceable parts inside
this product. Return the product to Wavelength
for service and repair to ensure that safety fea-
tures are maintained.
LIFE SUPPORT POLICY:
As a general policy, Wavelength Electronics, Inc.
does not recommend the use of any of its products
in life support applications where the failure or
malfunction of the Wavelength product can be
reasonably expected to cause failure of the life
support device or to signicantly affect its safety
or effectiveness. Wavelength will not knowingly
sell its products for use in such applications
unless it receives written assurances satisfactory
to Wavelength that the risks of injury or damage
have been minimized, the customer assumes all
such risks, and there is no product liability for
Wavelength. Examples of devices considered to be
life support devices are neonatal oxygen analyzers,
nerve stimulators (for any use), auto transfusion
devices, blood pumps, debrillators, arrhythmia
detectors and alarms, pacemakers, hemodialysis
systems, peritoneal dialysis systems, ventilators of
all types, and infusion pumps as well as other
devices designated as “critical” by the FDA. The
above are representative examples only and are not
intended to be conclusive or exclusive of any other
life support device.
CERTIFICATION AND WARRANTY
CERTIFICATION:
Wavelength Electronics, Inc. (Wavelength) certies
that this product met it’s published specications at the
time of shipment. Wavelength further certies that its
calibration measurements are traceable to the United
States National Institute of Standards and Technology,
to the extent allowed by that organization’s calibration
facilities, and to the calibration facilities of other
International Standards Organization members.
WARRANTY:
This Wavelength product is warranted against defects
in materials and workmanship for a period of one (1)
year from date of shipment. During the warranty
period, Wavelength will, at its option, either repair or
replace products which prove to be defective.
WARRANTY SERVICE:
For warranty service or repair, this product must
be returned to the factory. An RMA is required
for products returned to Wavelength for warranty
service. The Buyer shall prepay shipping charges
to Wavelength and Wavelength shall pay shipping
charges to return the product to the Buyer upon
determination of defective materials or workmanship.
However, the Buyer shall pay all shipping charges,
duties, and taxes for products returned to Wavelength
from another country.
LIMITATIONS OF WARRANTY:
The warranty shall not apply to defects resulting from
improper use or misuse of the product or operation
outside published specications.
No otherwarranty isexpressed orimplied. Wavelength
specically disclaims the implied warranties of
merchantability and tness for a particular purpose.
EXCLUSIVE REMEDIES:
The remedies provided herein are the Buyer’s sole
and exclusive remedies. Wavelength shall not be
liable for any direct, indirect, special, incidental, or
consequential damages, whether based on contract,
tort, or any other legal theory.
REVERSE ENGINEERING PROHIBITED:
Buyer, End-User, or Third-Party Reseller are
expressly prohibited from reverse engineering,
decompiling, or disassembling this product.
[e-mail]
web: www.teamWavelength.com
NOTES
Document Control release
Updated links to support new
website
Merged WTC3293-14001 and
WTC3293-14002
Updated Mechanical
Specications
Added socket manufacturer
Extended warranty, updated
limit chart, and section 1 of
operating instructions
Distributor
[email protected]
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