DSB45 Development Support Box
Confidential / Released
s
DSB45_HD_V05
Page 24 of 50
01.02.2008
3 Power
supply
3.1
Power supply for DSB45 and GSM module
The constant voltage supply on the PCB provides all the supply voltages required for
operating DSB45 and the GSM module. The power supply source can be a 9V laboratory
PSU and, in addition, an external battery used to feed only the GSM module. Depending on
the used type of power supply source, the S601 toggle switch must be in “Up” or “Down”
position as detailed in Chapter 3.1.1.
During normal operation the DSB45 and the GSM module must be powered from a
laboratory PSU connected to the jacks X604 and X605, both located at the back of the
DSB45 Development Support Box housing (Figure 5). In this case, the S601 toggle switch
must be flipped down.
In addition, DSB45 can provide the GSM module with power supplied from an external
battery. The external battery connects to the screw terminal block X602, as illustrated in
Figure 3. For battery operation, the toggle switch S601 must be flipped up. A charger circuit
is provided to charge the battery via an external plug-in charger attached to the X603
Lumberg connector (see Chapter 3.1.5).
Please note that S601 and X602 are only accessible if the DSB45 PCB is not installed inside
its housing.
Table 11: Connecting the laboratory PSU to X604 and X605
Voltage
Connector
Color
Supply v9V
4 mm jack X604
Red
Ground
4 mm jack X605
Black
Table 12: Recommended specification of the laboratory PSU
Parameter
Min.
Typical
Max.
Unit
Output voltage
8.5
9
9.5
V
Output current
1
A
Note: The output power of the laboratory PSU has to fulfill the SELV requirements in
accordance to EN60950.
Note: An overvoltage protection circuit (V609, V612) switches all voltage regulators off,
when the +9V supply voltage e10.5V (thyristor switch effect). In this case,
turn off the supply and restart with +9V.
The green LED V618 at the front panel indicates that the DSB45 and the GSM module are
connected to the power supply.
