Nokia 450 Handsets
After Sales Technical Documentation
Handsets HSN–5 and
HSN–5K
Original 50/96
NMP Part No. 0275278
After Sales
Handsets HSN–5 and HSN–5K
CONTENTS
Handset HSN–5 – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Documentation – 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Specifications – 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External signals and Connections – 4. . . . . . . . . . . . . . . . . . . .
Functional Description – 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Blocks – 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description – 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General – 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handset Module – 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Microphone Amplifier – 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HF–Microphone Amplifier – 6. . . . . . . . . . . . . . . . . . . . . . . . .
Earphone Amplifier – 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loudspeaker – 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CPU with Peripherals – 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hook Indicator – 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M2BUS Electronics – 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LCD Display – 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Display Controller/Driver – 7. . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Matrix – 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Illumination – 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Supply – 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power on/off Logic – 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillators – 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram of NK4U – 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Layout Diagrams of NK4U – 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List of NK4U (Version 1.0) Code: 0200343 – 11. . . . . . .
Exploded View of HSN–5/5K – 16. . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly parts of HSN–5 and HSN–5K – 17. . . . . . . . . . . . . . . . .
Technical Documentation
Page – 2
Original 50/96
After Sales
Technical Documentation
Handset HSN–5
Related Documentation
Introduction
The HSN–5/HSN–5K Handset has two main functions: to form an electro-
acoustic interface between the user and the transceiver unit and to pro-
vide means for controlling the transceiver unit and other accessories.
Handsets HSN–5 and HSN–5K
0200343 circuit diagram
9853967 layout and foil diagrams
0200343 parts list
0640049 exploded view
0260320 assembly parts (MHSN5)
0260386 assembly parts (MHSN5K)
The handset consists of handset module NK4U and mechanical parts.The
chassis of the handset consists of three parts: cover A, cover B and frame
C. The PC board is fixed in frame C, which is not visible from the outside.
The handset is connected to the radio unit with a modular connector. The
handset can be disconnected from the radio unit by pressing the lever be-
low the modular connector and pulling out the connector.
Technical Specifications
Temperature range:
–25°C – +55°C fully operational
–30°C – +70°C operational
–40°C – +85°C no damage
Supply voltages:
9.5 V minimum
13.2 V typical
17.0 V maximum
Current consumption:
standby, hook off, lights off 7 mA
active, hook off, lights off 15 mA
active, hook off, lights on 55 mA
Original 50/96
Page – 3
After Sales
Handsets HSN–5 and HSN–5K
External signals and Connections
The HSN–5/HSN–5K handset has a male 8–pin modular connector for
connecting the handset to M2BUS.
Pin Name Level Comments
1 EAR 325 mV
f = 1 kHz DC = 0.0 V
max. 1.2 V
2 MIC 240 mV
f = 1 kHz no DC connection
max. 2 V
3 AGND analog ground
4 POWER pull down res. < 1 kΩ
rms
rms
Technical Documentation
rms
/4 dBPa in MRP Z
rms
Z
out
out
> 10 kΩ
< 300 Ω
5 LSP max. 4 V
6 M2BUS input ”0” < 0.9 V output ”0”:pulldown<300Ω
7 DGND digital ground
8 +12 V minimum 9.5 V
Functional Description
Functional Blocks
HSN–5/HSN–5K Handset consists of the following functional blocks:
– Audio circuit
– Microprocessor
– Keyboard matrix
Z
rms
load
= 8 Ω
input ”1” > 1.9 V output ”1”:high imp.
output ”0” < 0.5 V max allowed cap. 2 nF
typical 13.2 V
maximum 17.0 V
Page – 4
– Keyboard illumination
– Display controller/driver
– Voltage converter
– LCD display
– Display illumination
Original 50/96
After Sales
Technical Documentation
The Audio circuit consists of the earphone, the microphone and the hf–
microphone and corresponding amplifiers.
The Handset loudspeaker is connected direct to the LSP line. The Microprocessor is a single chip version with internal ROM and RAM. The microprocessor controls all other blocks.
The Keyboard matrix is connected directly to microprocessor inputs and
outputs.
Keyboard illumination is accomplished with LEDs and is switched on, off
or dimmed by the microprocessor.
The Display controller/driver is connected to the microprocessor over a
parallel data line, and contains a display data RAM and character generator ROM/RAM.
The Voltage converter converts the voltages of +5V to –5V and divides
the voltage between +5V and –5V to five levels (V1...V5), which are connected to the display controller/driver.
Handsets HSN–5 and HSN–5K
The LCD display is connected to pcb and display drivers over two elastomer connectors.
The Display illumination is of the same type as the keyboard illumination.
Circuit Description
General
The user interface of the handset is of the menu type. Alphabetical characters can be used. A dot matrix display is provided.
Handset Module
The HSN–5/HSN–5K handset consists of the following functional blocks:
1. microphone amplifier
2. hf–microphone amplifier
3. earphone amplifier
4. loudspeaker
5. CPU with peripherals
6. Hook indicator
7. M2BUS electronics
8. LCD display
9. display controller/driver
10. keyboard matrix
11. illumination
Original 50/96
Page – 5
After Sales
Handsets HSN–5 and HSN–5K
12. voltage supply
13. power on/off logic
14. oscillators
Microphone Amplifier
Transistor V35 supplies a bias voltage for microphone B3. The supply is
filtered by C31, R69 and R70. The supply voltage on the emitter of transistor V35 is about 4.9 volts.
The frequency response of the microphone is filtered to obtain a suitable
shape by low pass filters C10/R60 and R10/R11/C11/C12/C14/R8 and
high pass filter R9/C13. The amplification is about 29 dB with a 1 kHz signal.
HF–Microphone Amplifier
Transistor V121 supplies a bias voltage for hf–microphone B5. The supply
is filtered by C119, C120 and C121. The supply voltage on emitter of transistor V121 is about 5.5 volts.
Technical Documentation
When the handset is connected to hf–junction box, EAR–line is on high
state. Switch N7 is then off and hf–microphone B5 is not in use.
Earphone Amplifier
The Earphone amplifier is of the differential type. Total amplification is
about 10 dB. The reference voltage is 4.3 volts in order to get a maximum
peak voltage without distortion.
Loudspeaker
The loudspeaker (8 Ω / 1.5 W) is connected direct to the coiled cord. It is
used to produce the keypad and alarm tones.
CPU with Peripherals
Microprocessor D1 is a single chip version with internal ROM and RAM. It
has 8 kbytes of ROM and 256 bytes of RAM. It controls the other blocks
on the basis of information coming from the M2BUS. In addition, it reads
the user inputs, and sends them to the M2BUS.
Hook Indicator
Page – 6
On–hook/off–hook information is received from a reed relay, which is located on the PC board and controlled by a magnet in the handset cradle.
Original 50/96
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