Rac - ILX Lightwave LDT-5900 Series User Manual

In V
setpoint voltage across the TEC. VTE mode is intended for applying a constant
voltage into a typical TE load (.1 < R < 2.5
In both I
output. However, sensor temperature is monitored for the purpose of
automatically turning off the output if the user specified limits are exceeded. (See
the "Output Off Registers" section in Chapter 3.) Auto-Tune is not available and
user selectable PID constants are not used in I
R
AC
Selecting R
module. The resistance of the TE module is measured by generation of a pseudo
AC current of small amplitude (< 15 mA). A small positive current (Ip) is input to
the module for time T and the output voltage (Vpi) across the TE is measured with
an ADC. The current is then reversed at the same amplitude (In) for time T, and
the output voltage (Vn) across the TE is again sampled by the ADC. The TE
resistance R
01_10
mode, the controller output current is continuously adjusted to maintain the
TE
and V modes, sensor measurements are not used to adjust the
TE TE
LDT-59XX
[002.500]
0
mode will enable the instrument to measure the resistance of a TE
AC
is then calculated with the following formula:
AC
R = .5 *
'i = 1..10
AC
'i = 10
TE
TEMPERATURE CONTROLLER
A
-
'i = 1..10
'i = 10
O P E R A T I O N S
Front Pa nel Opera t ion
and V modes.
TE
LDT-5980/ 5948
2
C H A P T E R
31