Service manual

Circuit Description
3-32
3-5-7-4 MHV (Electrification Output Enable)
Electrification Output Enable is the electrification output control signal 'PWM-LOW ACTIVE'.
When MHV-PWM LOW signal is received, Q401 turns on and the steady voltage will be accepted to the non-
inverting terminal of OP-AMP 324. As the voltage higher than the inverting reference voltage of OP-AMP,
which is set to R405 and R406, OP-AMP output turns high. This output sends IB to the TRANS auxiliary
wire through current-restricting resistance Q402 via R408 and C403 and Q402 turns on. When the current
is accepted to Q402, Ic increases to the current proportional to time through the T401 primary coil, and when
it reaches the Hfe limit of Q402, it will not retain the "on" state, but will turn to "off". As Q402 turns 'off',
TRANS N1 will have counter-electromotive force, discharge energy to the secondary unit, sends current to
the load and outputs MHV voltage through the high voltage output enable, which is comprised of Regula-
tion– circuit.
3-5-7-5 BIAS (supply/dev/blade output unit)
BIAS (Electrification Output Enable)Electrification Output Enable is the electrification output control signal
‘PWM-LOW ACTIVE’.When BIAS-PWM LOW signal is received, Q501 turns on and the steady voltage will
be accepted to the non-inverting terminal of OP-AMP 324. As the voltage higher than the inverting reference
voltage of OP-AMP, which is set to R506 and R507, OP-AMP output turns high. This output sends IB to
the TRANS auxiliary wire through current-restricting resistance Q502 via R509 and C504 and Q502 turns
on. When the current is accepted to Q502, Ic increases to the current proportional to time through the T201
primary coil, and when it reaches the Hfe limit of Q502, it will not retain the “on” state, but will turn to “off”.
As Q502 turns ‘off’, TRANS N1 will have counter-electromotive force, discharge energy to the secondary
unit, sends current to the load and outputs DEV voltage through the high voltage output enable, which is
comprised of Regulation-circuit.
MHV-PWM
U103 7407
R412 2.2K
18V
Q401 A708
R403 130K
R402
82K
R411 2K
R404
27K
C407
104
R406
2.2K
R405 220K
24VS
+
_
R408
47K
R409
390
KA324
C403
333
Q402
D526
24VS
T401
C404
3K/471
D402
4KV
C406
3K/471
R416
15M
R413
12M
ZD401
150V
OPC
R417
15M
MHV OUTPUT
BIAS-PWM
CON03-#24
U103-A
7407
2
5V
R520
26K
R519
2.2K
R502
2K
R503
100KF
R506
86.6KF
R508
47K
Q502
D526-Y
D502
4KV
C505
2KV 680
C506
3KV 471
ZD501
100V
ZD501
100V
R512
MGR1/2W 12MF
R514
MGR1/2W 50K
BLADE
SUPPLY
DEV
R515
MGR1/2W 50K
R516
MGR1/2W 50K
R509
47K
R510
430
R507
12KF
U101-B
KA324
R504
56.6KF
C501
104
C502
222
C504
333
R511
1W 3
R501
100
Q501
A708-Y
5
6
7
+
_
U1
C503
104
T201
KAB-007
24VS
1
5
2
4
7
6