Wavelength Electronics LDTC2/2E, Техническое описание и руководство по эксплуатации

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LDTC2/2 LASER DIODE DRIVER AND TEMPERATURE CONTROLLER
OPERATING INSTRUCTIONS –
TEMPERATURE CONTROLLER
!
Operate the LDTC2/2 with all loads attached.
If you short either the LD or TC output
connections during setup, current will flow
and possibly overheat/damage the WLD or
WTC.
RECOMMENDED ORDER OF SETUP
WTC configuration should be addressed first, using a
simulation diode load in place until the temperature control
section is working properly. After the temperature control
section is operating according to preferences, then the
laser diode load can be configured. Using a simulated diode
load until you are comfortable with WLD configuration and
operation is recommended in order to avoid any potential
damage to an expensive laser diode.
CONFIGURING HEATING AND COOLING
CURRENT LIMITS
The LDTC2/2 has two trimpots that independently set the
heating and cooling current limits: LIM A & LIM B. These
are 12-turn trimpots. Maximum current (2.2 A) is at full CCW
position.
Table 3
shows the meaning of the trimpots with
various sensors and load types. Note that PTC sensors
include RTDs, the LM335, and the AD590.
Table 3. Trimpot Function vs. Sensor & Load Type
SENSOR LOAD LIM A LIMITS LIM B LIMITS
Thermistor Thermoelectric Cool Current Heat Current
PTC Thermoelectric Heat Current Cool Current
Thermistor Resistive Heater OFF = Fully CW Heat Current
PTC Resistive Heater Heat Current OFF = Fully CW
WIRE OUTPUT CONNECTION
Use Table 4 to determine the connection from the LDTC2/2
to your thermoelectric or resistive heater.
Table 4. Wiring vs. Sensor & Load Type
SENSOR LOAD
TEC+
PIN J3:6
TEC-
PIN J3:7
Thermistor Thermoelectric Thermoelectric
positive wire
Thermoelectric
negative wire
PTC Thermoelectric Thermoelectric
negative wire
Thermoelectric
positive wire
Thermistor
Resistive
Heater
Quick Connect:
Connect the Resistive Heater to TEC+
& TEC- (polarity doesn’t matter). Adjust
the Cooling Current Limit A trimpot to
zero - fully CW.
Max V Connect:
Connect one side of the resistive
heater to TEC- and the other side to
the voltage source V
S
. LIM A trimpot
setting is then irrelevant. Allows for
approximately 1 V less internal voltage
drop across the LDTC.
PTC
Resistive
Heater
Quick Connect:
Connect the Resistive Heater to TEC+
& TEC- (polarity doesn’t matter). Adjust
the Cooling Current Limit B trimpot to
zero - fully CW.
Max V Connect:
Connect one side of the resistive
heater to TEC- and the other side to
the voltage source V
S
. LIM B trimpot
setting is then irrelevant. Allows for
approximately 1 V less internal voltage
drop across the LDTC.
CONNECT TEMPERATURE SENSOR
The LDTC2/2 is configured to operate a 10 kΩ thermistor
with a 100 μA bias current. If your application requires a
different sensor, please contact Wavelength for details.
Wire the thermistor between Pins 8 & 9 (SEN+ & SEN-) on
Connector J3.
!
Operating the LDTC without a temperature
sensor will drive maximum current through
the tec or heater, potentially damaging it.
For sensors other than thermistors, see “Configuration For
Alternate Temperature Sensors” on page 14 .