1
220V
R1 10/1W
1N4007
2
Brid g e D1-D4
4
3
220V
R2
100K 1/2W
1.5M 1/4W
R3
C12
2.2uF
D5
1N4007
C8
D7
1N4148
C9
D8 SB240
C10
220uF/15V
R18
1K
8.4V/2A
222M 400V
R12
22K
C12
224
C13
104
BAT1
C10
4.7uF/15V
R5
4.7
U2
Q1
D6
1N4818
R4
400
R6
200
R10
0.8K
R13
470K
R17
60K
BAT2
R11
100
13003
R8
2K
LED-R
LED-G
SE3901
OUT
Z
C4
10uF
Red Green
Vcc
Vctrl
R15
10K
R14
1K
Vcc
3.3n
C5
C6
10uF
Vout Vsense
Ictrl
GND
GND
U1
0.05ohm
R16
Fig.3 8.4V/1A 2 Cell Batteries Charger, using SE3901(TO94) and SE1052.
Note:
SE1052 integrates Voltage reference, Voltage setting and Current setting and LED drivers all in the
same IC. When the charging is on-going, the Red LED is On and the Green LED is Off. When the
Charging is completed, the Green LED is On and the Red LED is Off. The charging current can be
programmed by setting the R16 to the proper value. Please refer to SE1052 datasheet for details.
Revision 1/20/2009
Preliminary and all contents are subject to change without prior notice.
© Seaward Electronics, Inc., 2008. • www.seawardinc.com • Page 5
SEAWARD [ Seaward Electronics Inc. ]
