Keithley TEC SourceMeter 2510, Руководство пользователя

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4-2 PID Control Concepts Models 2510 and 2510-AT User’s Manual
Temperature control model
Figure 4-1 shows the overall control model for the system. The Model 2510 provides cur-
rent to the thermoelectric cooler (TEC), which uses the Peltier effect to maintain tempera-
ture at the desired setpoint. When current is forced through the TEC in one direction, the
device heats; when current is forced through the TEC in the opposite direction, the device
cools. In this manner, temperature is maintained at the setpoint, and equilibrium can be
maintained. Temperature feedback for the PID controller is provided by the temperature
sensor, which is in thermal contact with the thermoelectric cooler. PID control parameters
can be individually set to assure optimum temperature control as outlined below.
Figure 4-1
Temperature control model
Temperature control methods
The following discussion outlines comparisons between various temperature control
methods. Terms for this discussion are defined as follows:
• T
S
= setpoint temperature
• T
C
= cooler temperature
• W = power applied to thermoelectric cooler.
Model 2510
PID
Controller
Temperature Feedback Signal
Control Signal
Thermoelectric
Cooler
(TEC)
Temperature
Sensor
Thermal
Contact