Extended InGaAs Biased Detector
Chapter 4: Operation
Page 8
TTN134037-D02
200 mA current without this resistor. This will significantly decrease lifetime of the
battery.
The output bias voltage will be dependent on the load resistor as described
below. The A23 battery voltage characteristics show that the charge level is
almost depleted as the voltage drops below 10 V. For this calculation we assume
9.6 V since V
BAT
= low battery voltage – one diode drop (0.6 V) = ~9 V. The
detector will continue to operate until the battery charge is completely drained,
however these numbers provide a reference point at which the battery should be
replaced.
∗
:
9 ,
50 ,
2540
Note that V
out
is a theoretical value. If one would like to reverse calculate the bias
voltage more precisely using this feature, then a high impedance load is
suggested.
4.11. Battery Replacement
Thorlabs delivers each DET with an A23 12 V battery.
This battery is readily available at most retail stores, as
well as through Thorlabs. The battery supplied will deliver
about 40 hours with a 1 mA load, roughly equivalent to a
continuous 1.5 mW light source with responsivity 0.6 A/W
The supply current when the unit is on and no light is
applied is very small and should not significantly degrade
the battery.
Locate the battery cap directly above the output BNC.
Unthread the cap and remove the battery. Install the new
battery into the cap, negative side in, and thread back into
the DET. Be careful not to cross thread the cap into the
housing. The DET includes a protection diode to prevent
damage if the battery is installed backwards. The battery
direction is located on the housing.
