Nokia 450 Handset 1
After Sales Technical Documentation
Handset HSE–1
Original 50/96
NMP Part No. 0275277
After Sales
Handset HSE–1
CONTENTS
Technical Documentation
Page – 2
Original 50/96
After Sales
Technical Documentation
Handset HSE–1
Related Documentation
Introduction
Handset HSE–1
0200149 circuit diagram
D 0000111 block diagram
4F 9853821 layout and foil diagrams
6E 0200149 parts list
S 0640002 exploded view (HSE–1/1M)
S 0640038 exploded view (HSE–1XM/1XK)
6E 0260008 assembly parts (MHSE1)
6E 0260137 assembly parts (MHSE1M)
6E 0260156 assembly parts (MHSE1XM)
6E 0260212 assembly parts (MHSE1XK)
The HSE–1/1M/1XM/XK Handset has two main functions: to form an electroacoustic interface between the user and the transceiver unit and to
provide means for controlling the transceiver unit and other accessories.
The HSE–1/1M/1XM/XK is divided into two parts: the EH8M electronics
module and the MHSE1/1M/1XM/1XK mechanics. The EH8M module
consists of an 8–bit microprocessor with internal memory, a 2x8 character
display (+ 2 seven–segment) with one driver IC, keyboard, earphone, microphone, loudspeaker and corresponding amplifiers.
The MHSE1/1M/1XM/1XK Mechanics consist of the A–cover (front),
B–cover (rear), keyboard rubber mat, coiled cord, display frame and a
number of smaller parts.
The HSE–1/1M/1XM/1XK is designed for single–handset systems and for
mobile use only,so it has no audio switches, and is not provided with functions for a power–safe or sleep mode.
Technical Specifications
Mode of Operation
The HSE–1/1M/1XM/1XK has only one mode of operation, used when the
handset is operating as a combined handset and control unit. There is no
need for a local mode because all testing can be done by means of
M2BUS–messages.
External Signals and Connections
The HSE–1/1M/1XM/1XK has an 8–pin connector for connection to the
junction box, system cable and transceiver via coiled cord.
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After Sales
Handset HSE–1
Signal names and basic interface connections:
Pin Name Level Comments
1 VBS typ. 13.2 V
2 DGND Digital ground
3 MBUS Input: ”0”< 0.9 V Input levels at processor
4 LSP max. 4 V
5 POWER Series diode dropout 0.7 V
6 AGND Analog ground
7 MIC max. 2 V
8 EAR max. 1.2 V
Technical Documentation
min. 10.0 V
max. 17.0 V
”1”> 1.9 V input/RxD
Output: ”0”< 0.5 V Max allowed capacitance 2 nF
rms
rms
rms
No DC connection
DC 0.0 V
Display Specifications
The HSE–1/1M/1XM/1XK has a 2x8 (5x7) dot matrix display for 2 seven–
segment characters, a signal strength indicator (left bar) and a number of
fixed indicators over and under the character lines.
The yellow–green supertwist liquid crystal display is connected to the pcb
by means of elastomer connectors. The display is illuminated with green
LEDs from both sides.
Technical specifications for the display are as follows:
Display type Yellow–green supertwist lcd, transflective
Illumination colour yellow–green LED
Driving mode MUX 1:16, 1/5–bias
Driving voltage 7.5 V at +25°C
Temp. compensation 30 mV/°C
Lens thickness 1.1 mm
Display driver NEC µPD7228AG
Storage temperature –30...+85°C
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Oper. temperature –25...+70°C
Humidity typ. 50% RH max. 90% RH
Response times t(
) < 100 ms (+25°C) < 1500 ms (–25°C)
rise
) < 100 ms (+25°C) < 1500 ms (–25°C)
t(
fall
Viewing angle min. 40 degrees to all sides from centre
line (CR 2:1)
Main viewing direction 12 o’clock
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After Sales
Technical Documentation
Functional Description
Functional Blocks
HSE–1/1M/1XM/1XK Handset consists of the following functional blocks:
– Audio circuit
– Microprocessor
– Keyboard matrix
– Keyboard illumination
– Display controller/driver
– Voltage converter
– LCD display
– Display illumination
Handset HSE–1
The Audio circuit consists of the earphone and the microphone and corresponding amplifiers.
The Handset loudspeaker is connected direct to the EXTS 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.
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.
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After Sales
Handset HSE–1
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.
Construction
The handset consists of two body halves with a PC board inserted in between. A coiled cord, a speaker, an earphone and a microphone are
wired to the PC board.
Handset Module
The HSE–1/1M/1XM/1XK handsets consist of the following functional
blocks:
1. microphone amplifier
Technical Documentation
2. earphone amplifier
3. loudspeaker
4. CPU with peripherals
5. Hook indicator
6. M2BUS electronics
7. LCD display
8. display controller/driver
9. keyboard matrix
10. illumination
11. voltage supply
12. power on/off logic
13. 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.
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.
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