Nokia 2190 Service Manual lch 2
Programmes After Market Services (PAMS)
Technical Documentation
CIGARETTE LIGHTER
CHARGER LCH–2
PAMS
NHB–3
Technical Documentation
AMENDMENT RECORD SHEET
Amendment
Number
Date Inserted By Comments
Cigarette Lighter Charger LCH–2
Original 26/97 Page 2
PAMS
NHB–3
Technical Documentation
Cigarette Lighter Charger LCH–2
Contents
Cigarette Lighter Charger LCH–2 Page 4
General Page 4
Technical Summary Page 4
States of Charge and Charge Control Page 4
Charge Indication Page 4
Electrical Specifications Page 5
Functional Description Page 5
General Page 5
Converter Page 5
Oscillator Page 6
Pulse–Width Control Page 6
Current Limiting Page 6
Block Diagram of AL4 Page 7
Circuit Diagram of AL4 Page 8
Layout and Foil Diagrams of AL4 Page 9
Parts List of AL4 Code: 0200315 Page 10
Exploded View Page 13
Assembly Parts Page 13
Cigarette Lighter Charger LCH–2
Original 26/97 Page 3
PAMS
NHB–3
Technical Documentation
Cigarette Lighter Charger LCH–2
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6E 0200044 parts list AL4
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6E 0260062 assembly parts LCH–2
6E 0260094 assembly parts LCH–2U
General
The LCH–2 cigarette lighter charger is used for charging the battery of the
handportable phone from the 12 or 24 V cigarette lighter socket of a motor vehicle. The charger is provided with LED charging indication.
Technical Summary
Cigarette Lighter Charger LCH–2
States of Charge and Charge Control
The LCH–2 cigarette lighter charger is used for charging a handportable phone
from a car battery. A constant–current or constant–voltage output is provided
depending on the operating state of the phone.
Charge current is supplied through a series switch transistor located in the
phone. When the transistor is on the charger supplies a constant current to the
phone. The phone is then in the rapid charge mode.
When the transistor is off no current is supplied to the phone and the charger is
in the constant–voltage mode.
Once fully charged in the rapid charge mode, the battery is kept full by means
of pulsed charging. Current is switched on and off at a variable duty cycle and a
frequency of a few Hz.
Charge Indication
Charger states are indicated with a dual–colour LED located in the cigarette
lighter charger unit.
In addition, the phone LCD contains a three–bar battery status display, operative when power for the phone is on.
”Charging sequence active” (state A) is indicated by the bars being lit sequentially, starting from the bottom one.
”Battery full” (state B) is indicated by all three bars steadily lit.
Original 26/97 Page 4
PAMS
NHB–3
Technical Documentation
Phone operating status LED Display
Cigarette lighter charger connected
to vechile, phone disconnected green
Phone connected to charger, charging
disabled due to battery temperature green state A
Rapid charge red state A
Battery full –> trickle charge green state B
Calling state green/ state A
*) Battery capacity is maintained during a phone call by occasional rapid charge
cycles. Consequently, the LED can be indicating either red or green.
Electrical Specifications
Operating input voltage: 9 to 32 V d.c.
Input current without phone: < 60 mA
Cigarette Lighter Charger LCH–2
*)
red
Max. input current: 1.8 A
Output voltage:
• constant voltage 12.5 ±1 V/0...400 mA
• constant current 800 ±70 mA/5.0...10 V
Functional Description
General
The charger module consists of a switched–mode converter and a bicolour indicator LED. The converter is of the step up/down type, i.e. the output voltage
can be lower or higher than the input voltage.
Converter
Converter input current is received via filter capacitor C101. The converter consists of coils L110, L112, FET switch V112, d.c. level shifting capacitor C111
and Schottky diode V113. Output energy is stored and filtered by C112, L111
and C113.
In series with converter coil L112 is resistor R116, used for measuring the output current. When operating, the converter generates a negative voltage drop
(as compared to ground level) at R116, directly proportional to output current.
Converter control is by N110, a quad comparator with open–collector output.
The 5 V reference supply is generated by regulator N100.
Original 26/97 Page 5
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