Newport LDC-3706 Series, Руководство пользователя

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December 2019 16 LDC-3706 Series Laser Controller
TEC Grounding Considerations: The TEC output connections of the LDC-3706 instruments are
isolated from the chassis ground, allowing either output terminal to be grounded. If a terminal is
grounded, be sure to connect it only to the Earth ground.
Connecting one of the TEC output terminals to analog or digital ground causes
catastrophic damage to the instrument. For the TEC connector, if any one terminal
pin is grounded, then no other terminal pin can be grounded. Do NOT connect the
Sensor (-) and TE Module (-) to the same ground; damage to the instrument and
devices will occur.
The Temperature Control output terminals of the LDC-3706 Laser Controller (TE
Module (+) and TE Module (-)) should never be shorted together or loaded with less
than 0.1
Ω . Doing so may result in damage to the instrument.
Analog Modulation Input : An isolated BNC connector is located on the front panel of the LDC-3706
and provides the capability to modulate the output of the laser current source. This connector can
accept a signal from 0 to 10 V, and a nominal input impedance of 1
k Ω . The transfer function and
bandwidth of this input is dependent on the mode of operation of the instrument. For further details
please consult the
Specifications section of Chapter 1 . This feature is useful in applications requiring
modulation of the output current without using the GPIB or USB remote interfaces.
Analog Temperature Control Input : An isolated BNC connector is located on the rear panel of the
LDC-3706 that provides the capability to adjust the temperature setpoint by applying a voltage signal.
The LDC-3706 can accept a signal from -5 V to +5 V, with a gain of 2°C/V and bandwidth of 5 Hz.
This feature is useful in applications requiring sweeping of the temperature without using the GPIB or
USB remote interfaces.
External Fan Control: The LDC-3706 features the ability to control an external fan through the
25-pin DSUB connector. This circuit can provide up to 500 mA and may be controlled from 1 to
12 VDC. The circuit will automatically increase the voltage to 12 VDC to start a fan from a
stopped condition and will regulate to the desired voltage once more than 20 mA is drawn.
Pseudo 4-Wire Temperature Control Measurements: The LDC-3706 offers a pseudo 4-wire
temperature sensor measurement feature which helps to minimize errors induced by cable
resistance both in thermistor/RTD sensor modes as well as on the TEC output terminals. This
feature is enabled by connecting the appropriate ‘sense’ terminals and is disabled by leaving
them disconnected.
External Trigger Output: For applications where an external measurement must be made
synchronously with the operation of the LDC-3706, a TTL level trigger output is provided
through a grounded, female BNC connector on the rear of the instrument. For further
information please consult the
Specifications section of Chapter 1.