KAC-X542
CIRCUIT DESCRIPTION
� Current detection circuit
Amplify and rectify potential differences at two points in the primary-side current circuit and send it to the AD-port of the MPU and obtain data for displaying current value.
1K
MPU AD-PORT OUTPUT
0.01
0.01
VOLTAGE LEVEL DETECTION
1K L5 2 3 8 68
10K 7 4 6 5 1 10K
IC6 (2/2)
IC6 (1/2)
+
AMP RECT
� Constant current output circuit
Remove troubles caused by the potential differences between the constant current output and the GND, so that the GND potential differences between the head unit and the AMP is not overlapped in the AMP to head unit communication.
J3
4 3 7
10u35
2 6 10 13
1 5
AD-I
8 12
Q95 to Head unit
47
100K
Q93 Q90
10K
11
9
47
from MPU
REQC
Q96
10K
Head unit-GND
Head unit GND CONSTANT CURRENT AMP GND
� I2C buffer
Using an IC for I2C communication, between-AMP communication is conducted so that there will be no trouble from GND potential differences.
5
to OTHER AMP TRANSMISSON RECEIVE
4.3K 4.3K 270
J4
24 1 3 270 CLK
15K
D93
IC9
79 270 68 DATA 10u25 10K
1 8
SX VCC 3 6 1.8K TX RY 4 5
10 11
1.5K
D91
2 7
RX SY
220 20K 12K 1.8K
to MPU TRANSMISSON RECEIVE
GND TY
BOTH DIRECTION BUFFER
ADJUSTMENT
No. Item Alignment Point Method Connect a DC voltmeter between VR5 (A-Lch) 1 IDEL CURRENT VR6 (A-Rch) VR7 (B-Lch) VR8 (B-Rch) the following emitter resistors. R347 (A-Lch) R348 (A-Rch) R447 (B-Lch) R446 (B-Rch) 2.5mV Over 2 minutes aging is required. PC BOARD on page 10 and 11. Align For Note Fig.
