TC5 TEMPERATURE CONTROLLERS0 pages

TELEDYNE
JUDSON TECHNOLOGIES
A Teledyne Technologies Company
1/6
221 COMMERCE DRIVE
MONTGOMERYVILLE, PA 18936-9641
PHONE: 215-368-6901
FAX: 215-362-6107
www.teledynejudson.com
TELEDYNE
JUDSON TECHNOLOGIES
A Teledyne Technologies Company
PB 3315 September, 2003
TC5
TEMPERATURE CONTROLLERS
Operating Instructions
GENERAL
The TC5 Controller is one of
several models of controllers
manufactured by Teledyne Judson
designed to provide high stability
temperature control with a design
approach that is user friendly.
Figure 1 is a block diagram that
illustrates the major components
of this controller.
PRINCIPLE OF
OPERATION
Please refer to Figure 1 as the
following section is reviewed.
The Controller is powered by
standard AC input voltages (115
or 230). Incoming AC voltage is
converted to low voltage DC for
use by the control circuitry.
These low power voltages are
available on the rear panel
connector J1 and can be used to
power low voltage external
circuitry. Also included in the
controller is a separate DC
voltage power source for driving
the thermoelectric cooler (TC).
The resistance of the thermistor
used to measure the temperature
of the TC is converted to a DC
voltage and compared to the
voltage used to establish the set
point. The difference between the
set point voltage and the voltage
resulting from the conversion of
the thermistor resistance is
amplified and applied to a power
driver. The power driver controls
the current flowing in the TC to
bring the thermistor resistance
equal to the set point. While this is
occurring, an integral term is
developed to maintain the required
current flow to the TC when there
is no difference between the set
point and the thermistor resistance.
The current limit control prevents
TC currents from exceeding the
preset value (Imaximum for
thermoelectric cooler). This
feature helps to prevent damage or
reduced performance of the TC.
Figure 1
TC5 Block Diagram