ILX Lightwave LDC-3700C Series, User Manual, Page: 57 / 176

O P E R A T I O N S
Functions and Features
04_09 LDC-3700C Series
41
C H A P T E R
2

connected to the laser output, and therefore, no dummy load is required for
precise adjustment of the current limit. Furthermore, since the current limit
circuitry is fully independent of the main current control, the current limit can be
adjusted safely, even while the
LASER output is active.
Now you are ready to modulate the laser injection current. To enable the
controller output, in the
LASER MODE section of the front panel, press the push
button labeled OUTPUT . The accompanying LED labeled ON will illuminate
indicating that the laser current source's output is enabled. The instrument will
drive the current source to the value set by the corresponding
LASER MODE set
point . When the LASER output is off, an internal short is placed across the laser
output. This condition is indicated by the OUTPUT SHORTED indicator becoming
lit. To disable the output, press the OUTPUT push button again.
Boosting the TE Controller
For users who need more than 16 Watts of TE Controller power, a booster current
source may be required and the LDC-3700C Series Temperature Controller may
be used as the control element. This section describes the use of the
LDC-3700C's Temperature Controller as a remote temperature controller.
Whenever a connection is present between the BOOSTER PRESENT (pin 14)
and DIGITAL GROUND (pin 15) of the back panel TEC Input/Output connector
(see Figure 2.5), the LDC-3700C's TEC OUTPUT will be disabled. In this case, a
BOOST CONTROL signal voltage equal to ±10.0 Volts will be available for
controlling an independent current source. This control voltage is available
between the
BOOST CONTROL (pin 10) and AGND (pin 9).
Figure 2.5 Rear Panel TEC Connector
ON
OUTPUT
I
HBW
P
I
SELECT
LASER MODE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1, 2 TE Module (+)
3, 4 TE Module (-)
5 TE Module Shield
6 Sensor Shield
7 Sensor (+)
8 Sensor (-)
9 Analog Ground
10 Control Signal
11 Voltage Limit
12 Current Limit
13 Temp. Limit
14 Booster Present
15 Digital Ground