8-10. PCB SUB AssÕy (INVERTER PCB)
1. EMI circuit
COMMON MODE NOISE is attenuated by CHOKE LFI, NORMAL MODE NOISE and D.C
RESISTANCE.
2. Rectifier circuit
Holding voltage is converted to DC voltage by BRIDGE DIODE.
It is ELECTROLYTIC CAPACITOR and composed of balance circuit
3. First starter circuit
The current converted to DC by C
2
is charged to C
3
through R
3
. When more than 35V is charged at C
3
, the
first switching operation is initiated by sending the current to BASE of Q
2
through DAC R
1
and D
5
maintain
enough potential difference between EMITTER and COLLECTOR of TRQ
2
for easy first switching.
4. Switching circuit
Q
2
becomes ON by the current from DAC and then, the current goes through C
6
C
7
C
5
CH
1
TR(C E). The current sent to PT
1
is held at PT
3
and by this holding current, Q
2
maintains ON state.
Switching circuit is consisted when OSC COIL becomes saturated by line current, counter-electromotive force
occurs at PT
3
, electromotive force is held at PT
2
, and then, Q
1
comes to be operated.
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