Circuit Description
4-8
Samsung Electronics
4-5-3 Master and Slave Mode
4-5-4 Watch Dog and Reset Circuit
MPU U1 Reset pin is active in low state. U4 is used
as A/D reference voltage for MPU and whole
charging system, so the circuitry composed of
Q30-Q32 and D30 detects the voltage. In normal
state, Q31 turns on so U4 pin 3 becomes low. It
causes MPU Reset to be high. If an excessive
impulsive voltage is supplied to U4, Q30 turns on,
and U4 pin 3 becomes high. It causes MPU to be
reset.
4-5-5 Timer
Timer is used to protect the battery from being
overcharged. The timer is set at initial routine. If
fast charge is not completed until maximum time
value, fast charge is stopped by the timer and it
moves to automatic trickle charge routing. This is
the final step to protect battery from excessive
charging and damage. There are four timers
available, and the default timer is 140 minutes.
4-5-6 Temperature Detection
The battery temperature and ambient temperature
can seriously damage Ni-MH battery, so the
temperature is constantly detected by MPU. The
ambient temperature is detected by MPU pin 19
through R54, TH1, and R56. The battery
temperature is detected by R45, R46, and NTC,
and measured as A/D value by MPU pin 20.
4-5-7 Charging Voltage Detection
The charging voltage of the battery is detected by
R47 and R48, and measured as A/D value by MPU
pin 18. The parameters, -
ßE
V, 0
ßE
V, and Vmax,
used for checking charge level are also measured
by MPU.
4-5-8 Discharging Circuit
Discharging is available on the rear port only.
When MPU pin 14 acknowledges that the
discharging button is pressed, MPU pin 2 starts
discharging. Discharging is initiated immediately
when the button is pressed for over than 0.7
seconds within 30 seconds after battery installed. If
the voltage reaches 1 V/cell by discharge,
discharging stops, then fast charging starts
automatically.
HIGH
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
LOW
LOW
HIGH
LOW
HIGH
LOW
LOW
HIGH
HIGH
Signal
MPU(11)
CUR_CTRL
MPU(4)
CHG_A
MPU(3)
CHG_B
MPU(13)
FRNT_GRN
MPU(9)
REAR_GRN
Status
Time (minute)
Time-1 (RX1)
Time-2 (RX2)
140
VCC
VCC
210
GND
VCC
280
VCC
GND
350
GND
GND
Trickle charging on both front and rear ports
Fastcharging on front port
Fastcharging on rear port
Front port master charging
Rear port slave charging
Rear port master charging
Front port slave charging
Fast charging on front port
Trickle charging on rear port
Fast charging on rear port
Trickle charging on front port
Summary of Contents for SCH-1900
Page 2: ...Samsung Electronics Co Ltd GH68 60620A Printed in Korea ...
Page 27: ...Samsung Electronics 6 1 6 Troubleshooting 6 1 Logic Section 6 1 1 No Power ...
Page 29: ...Samsung Electronics 6 3 Troubleshooting 6 1 3 Abnormal Backlight Operation ...
Page 30: ...Troubleshooting 6 4 Samsung Electronics 6 1 4 Abnormal Key Data Input ...
Page 31: ...Samsung Electronics 6 5 Troubleshooting 6 1 5 Abnormal Keytone ...
Page 32: ...Troubleshooting 6 6 Samsung Electronics 6 1 6 Abnormal Alert Tone ...
Page 33: ...Samsung Electronics 6 7 Troubleshooting 6 2 Transmitter Section ...
Page 34: ...Troubleshooting 6 8 Samsung Electronics ...
Page 35: ...Troubleshooting 6 9 Samsung Electronics 6 3 Receiver Section ...
Page 36: ...Troubleshooting 6 10 Samsung Electronics ...
Page 37: ...Samsung Electronics 6 11 Troubleshooting ...
Page 39: ...Troubleshooting 6 13 Samsung Electronics 6 4 2 No Power HHP PWR 5 8V 13 5V Supply ...
Page 40: ...Samsung Electronics 6 14 Troubleshooting 6 4 3 Hands Free RX Path ...
Page 41: ...Troubleshooting 6 15 Samsung Electronics 6 4 4 Hands Free TX Path ...
Page 42: ...Samsung Electronics 6 16 Troubleshooting 6 5 Desk Top Rapid Charger ...
Page 43: ...Troubleshooting 6 17 Samsung Electronics 6 6 Cigarette Lighter Adapter 6 6 1 Power Fault ...
Page 44: ...Troubleshooting 6 18 Samsung Electronics 6 6 2 LED On Fault ...
Page 45: ...Troubleshooting 6 19 Samsung Electronics 6 6 3 Charge Fault ...
Page 46: ...Troubleshooting 6 20 Samsung Electronics 6 7 Travel Charger ...
Page 48: ...Exploded View and its Parts List 7 2 Samsung Electronics 7 1 Main Set Exploded View ...
Page 50: ...Exploded View and its Parts List 7 4 Samsung Electronics 7 3 Hands Free Kit Exploded View ...
Page 58: ...Exploded View and its Parts List 7 12 Samsung Electronics 7 11 Main Set Packing Layout ...
Page 60: ...7 14 Samsung Electronics Exploded View and its Parts List 7 13 Hands Free Kit Packing Layout ...
Page 62: ...7 16 Samsung Electronics Exploded View and its Parts List ...
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Page 100: ...10 2 Hands Free Kit Block Diagram ...
Page 101: ...10 3 Desk Top Rapid Charger Block Diagram ...
Page 102: ...10 4 Cigarette Lighter Adapter Block Diagram ...
Page 103: ...10 5 Travel Charger Block Diagram ...
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