Analog Out; Setting The Current Limit; Constant Current Mode (Cc) - THORLABS LDC200C series Operation Manual

LDC200C Series

3.1.4 Analog Out

The output "CTL OUT"
The output voltage ranges from:
· 0 ...+10 V with cathode grounded
· 0 ... -10 V with anode grounded.
When connecting a load avoid ground loops. The load resistance should be >10 kW. The
conversion coefficient for this output can be calculated to:
where I is the max. output current for the given controller.
max
Example:
For an LDC202C with a max. output current of 200mA the conversion coefficient k
equal to 0.05 V/mA.

3.2 Setting the Current Limit

Prior to switch on the laser diode, always set an appropriate injection current limit to protect the
laser diode from destruction:
· Switch on the unit - button "LINE" (F10).
· Make sure the laser current is switched off
· Select parameter "I
· Use a screwdriver to set the desired current with the potentiometer "LIM I" (F11).
Note
The current limit can be displayed at any time by selecting the parameter "I
If the laser current reaches it's limit during operation, the LED "LIMIT" (F5) lights up and a short
beep alerts about that. The current limit can also be adjusted when the output is switched on.
Avoid any adjustments when the LED "LIMIT" (F5) lights up.

3.3 Constant Current Mode (CC)

· Switch on the LDC2xxC.
· Make sure, that the current limit "I
· Make sure that the correct
· Connect the laser diode
· Select the display "I
· Turn the adjust knob (F9) completely counter clockwise.
· Select constant current mode ("I") by pressing the key "CONST" (F24) until LED "I" (F22)
lights up.
· Switch on the output by pressing the key "LASER ON" (F8). The LED "LASER ON" (F7)
lights up, the output is activated and the current slowly rises (about 1 s) to the value set with
knob (F9).
Note
The current output can be switched on only if the jack "LD OUT" (R6) is connected correctly
14
(R3) delivers a DC voltage, proportional to the actual laser current.
10
k = 10V/I
CTL OUT
" (key F17 or F18).
LIM
" is
LIM
laser diode polarity
.
12
" using the keys (F17) or (F18).
LD
[V/mA]
max
adjusted properly
14
is set.
12
"
LIM
.
© 2015 Thorlabs
is
CTL OUT