Bosch Appliances Home Security System 3.5 User Manual

Bosch Security Systems | 2011-02

2011-02 | Installation and User Instructions | 5 | Call Stations

en | 223

The value of resistor R in figure 18.9 depends on the 
voltage of the external source, the forward voltage of the 
LED and the current flowing through the LED:

For example, the voltage of the external source is 24 V, 
the forward voltage of the LED is 2 V and the current 
flowing through the LED is 10 mA, then:

The external interface for external speakers consists of a 
pin header connector with 6 positions (see the PCB for 
the pin numbering.) When using an external 
loudspeaker, also connect a volume control (see section 
18.2.2).

The external interface for the keypad (kits) consists of an 
IDC connector with 16 positions. Keypads are 
connected in series. That means there is only a direct 
connection between the call station kit and the first 
keypad. The second keypad is connected to the first, the 
third to the second etc. using standard flat cables.

Warning
Do not connect DC or AC signals to the control 

inputs, otherwise the input circuit may be 

damaged. Only use voltage-free contacts.

Pin

Signal

1, 2, 3

Speaker +

4, 5, 6

Speaker -

Impedance:

8 to 32 ohm

Signal/Noise ratio:

typical 80 dB ± 3 dB at max. output

Output power:

typical 100 mW, max. 300 mW

–

---------------------------------------------

=

24 2

–

10 10

3

–

⋅

---------------------

2200

Ω

( )

=

=

Pin

Signal

1

Synchronization line.

2

GND

3

Interrupt line (INT)

4

GND

5

Data I2C (SDA)

6

GND

7

Clock I2C (SCL)

8

GND

9

Power

10

GND

11

Power

12

GND

13

Power

14

GND

15

Power

16

GND