Troubleshooting - THORLABS DET10A Operating Manual

the voltage drops below 10V. For this calculation we assume 9.6V since VBAT = low battery voltage – one diode drop
(0.6V) = ~9V. 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.
Battery Replacement
Thorlabs delivers each DET with an A23 12V battery installed. This battery is readily available at most retail stores, as
well as through Thorlabs. The battery supplied will deliver about 40 hours with a 1mA load, roughly equivalent to a
continuous 1.5mW light source at peak wavelength. 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.

Troubleshooting

There is no signal response.
- Verify that the power is switched on and all connections are secure.
- Verify the proper terminating resistor is installed if using a Voltage measurement device.
- Verify that the optical signal wavelength is within the specified wavelength range.
- Verify that the optical signal is hitting the detector active area.
- Connect the DET to an oscilloscope without a terminating resistor installed. Most general purpose
oscilloscopes will have a 10MΩ input impedance. Point the detector toward a fluorescent light and verify that
a 60Hz (50Hz outside the US) signal appears on the scope. If so the device should be operating properly and
the problem may be with the light source or alignment.
There is an AC signal present when the unit is turned off.
The detector has an AC path to ground even with the switch in the OFF position. It is normal to see an output
response to an AC signal with the switch in this state. However, because the detector is unbiased, operation in this
mode is not recommended.
The output appears AC coupled with long rise times and the power switch ON.
This is usually an indication that the battery level is low and needs to be changed. See the Battery Check and
Replacement Section.
Maintaining the DET10A
There are no serviceable parts in the DET10A optical sensor. The housing may be cleaned by wiping with a soft
damp cloth. The window of the detector should only be cleaned using isopropyl alcohol and optical grade wipes. If
you suspect a problem with your DET10A please call Thorlabs and an engineer will be happy to assist you.
Contact
Americas
Thorlabs Inc.
435 Route 206 North
Newton NJ 07860
USA
Ph: (973) 579-7227
Fax: (973) 300-3600
www.thorlabs.com
Email:
techsupport@thorlabs.com
V = V
OUT
For V (min) = 9V, R
BAT
ON/OFF
+
PROTECTION
BATTERY
DIODE
Figure 3 – Battery Check Schematic
Europe
Thorlabs GmbH
Gauβstr. 11
85757 Karlsfeld
Germany
Ph: +49 (0) 8131-59-56-0
Fax: +49 (0) 8131-59-56-99
www.thorlabs.com
Email:
Europe@thorlabs.com
13052-S01 Rev C 11/8/2011
[R / (R +R )]
BAT LOAD LOAD CL
= 50Ω, and R
LOAD CL
V = 410mV
OUT
VBAT
VBIAS OUT
RCL RS
50
1000
PUSHBUTTON
SWITCH
UK and Ireland
Thorlabs, LTD.
1 Saint Thomas Place, Ely
Cambridgeshire CB7 4EX
Great Britain
Ph: +44 (0) 1353-654440
Fax: +44 (0) 1353-654444
www.thorlabs.com
Email:
sales.uk@thorlabs.com
Page 3 of 5
= 1050Ω
BNC
VOUT
RLOAD
Scandinavia
Thorlabs Sweden AB
Box 141 94
400 20 Göteborg
Sweden
Ph: +46-31-733-30-00
Fax: +46-31-703-40-45
www.thorlabs.com
Email:
Scandinavia@thorlabs.com
Japan
Thorlabs Japan, Inc
5-17-1, Ohtsuka
Bunkyo-ku,Tokyo 112-0012
Japan
Ph: +81-3-5977-8401
Fax: +81-3-5977-8402
www.thorlabs.jp
Email:
sales@thorlabs.jp