Bipolar Control; Warm Up Supply - Lakeshore 335 User Manual

5.4 Bipolar Control

5.5 Warm Up
Supply
Menu Navigation:
Zone SettingsQOutput (1, 2)QZone to edit (1 to 10)
Interface Command: ZONE
The most common type of temperature control output device is a resistive heater,
which requires only unipolar output, since they will add heat regardless of the polar-
ity of the excitation voltage. There are, however, temperature control devices that are
bipolar. These devices, such as thermoelectric devices, can work in both polarities,
moving heat from one side of the device to the other when a current is applied. There-
fore, a surface can be heated or cooled using a bipolar temperature control device. For
these types of bipolar devices, the Model 335 features a bipolar control mode. In this
mode, the Model 335 is configured to drive these devices to control temperature
using Output 2 in Voltage mode. Refer to section 2.11 for more information about
thermoelectric devices.
To use Output 2 for bipolar control, first set the Heater Output Type parameter to
Voltage, then set the polarity to Bipolar. The Closed Loop PID control mode can then
be used to control a thermoelectric device, providing a control output of
-10 V to +10 V. Refer to 2.11 for information on thermoelectric devices. Refer to sec-
tion 3.7.5.4 for information on scaling the output for voltages less than 10 V.
Menu Navigation:
Output SetupQOutput 2QOutput Type (Voltage)
Interface Command: ANALOG
Warm Up Supply mode is designed for controlling an external power supply used for
rapidly increasing the temperature in the controlled system, for example, to bring a
system to room temperature in order to change samples. Refer to section 3.7.5 for
information on using an external power supply for Warm Up Supply mode.
Warm Up Supply mode is only available when Output 2 is in Voltage mode. The Con-
trol Input setting, determines the sensor that is used for feedback in the Warm Up
Supply mode. Refer to section 4.5.1.7.1 for details on the Control Input parameter and
section 4.5.1 for Output Type.
Once Warm Up Supply mode is configured, use the Setpoint key to set the desired
temperature, then use the Heater Range key to activate the output by setting the
range to On. The front panel display must be configured to show the Warm Up control
loop for the Setpoint and Heater Range keys to be used. Refer to section 4.2 and
section 4.3 for details on front panel keypad operation and display setup.
The Power Up Enable feature determines if the output will remain on after power is
cycled. Refer to section 4.5.1.4 for details on the Power Up Enable feature.
Menu Navigation:
Output SetupQOutput 2 QOutput Type (Voltage)Q Output Mode (Warm Up Supply)
Interface Command: OUTMODE
5.4 Bipolar Control
Q Polarity (Bipolar)
ENTER
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