C A L I B R A T I O N A N D T R O U B L E S H O O T I N G
Calibration Overview
04_09
LDC-3700C Series
141
C H A P T E R
5
ITE Current Calibration
This procedure is for calibrating the ITE bi-polar constant current source. This
procedure calibrates the zero current set point automatically, then it automatically
drives the TE current output to internally set limits of
2 amp. When each of these
values is reached and is stable, the user enters the actual value of the current, as
measured by an external DMM. The LDC-3700C Series Laser Diode Controller
then automatically calibrates the TEC current source and limits.
1
With the output off, connect a 1
, 20 W resistor across the TEC output terminals (TE
and TE Module -).
2
Connect a calibrated DMM across the load resistor. You will be calculating TE current in
the following manner using Ohm's Law:
I = V / R
where V is the accurately measured voltage across the resistor, and R is the accurately
measured load resistance. I is the calculated current in Amps. (A 4-point probe
resistance measurement is recommended.)
3
Make sure that the
TEC
output is off before entering the I
TE
calibration mode. Press the
(
Communications
)
LOCAL
and (
TEC
DISPLAY
)
I
TE
switches at the same time to place
the Controller in TEC Current Calibration mode.
The Laser display blanks and the TEC display drives the output to a value of zero (0.000)
amps as the Temperature Controller calibrates itself. After 20 seconds, the TEC controller
drives the output to 2.000 amps. Once stable, the temperature controller is ready to enter
the actual TE current value.
4
Press and hold the (
PARAMETER
)
SET
switch and turn the Adjust Knob until the
TEC
display shows the correct value (absolute value of the I
TE
measurement). Release the
(
PARAMETER
)
SET
switch to store the new calibration value into non-volatile memory
The Controller drives the TE output current to the negative value of -2.000 Amps.
5
Repeat step 4 for the negative polarity of the TEC output current.
After the negative polarity value of the TEC output is entered, the controller automatically
calibrates its current limits and set points, indicated by the flashing TE Current Limit
indicator. The controller then returns to the state before calibration.
Summary of Contents for LDC-3700C Series
Page 2: ......
Page 8: ...L I S T O F FIG U R E S vi LDC 3700C Series...
Page 10: ...L I S T O F TA B L E S viii LDC 3700C Series...
Page 78: ...RE M O T E O PE R A T I ON Command Syntax 62 LDC 3700C Series C H A P T E R 3...
Page 150: ...C O M M A N D RE F E R E N C E Command Reference 134 LDC 3700C Series C H A P T E R 4...