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1-5. PW1 STROBE CIRCUIT DESCRIPTION
1. Charging Circuit
When UNREG power is supplied to the charge circuit and the
CHG signal becomes High (3.3 V), the charging circuit starts
operating and the main electorolytic capacitor is charged with
high-voltage direct current.
However, when the CHG signal is Low (0 V), the charging
circuit does not operate.
1-1. Power switch
When the CHG signal switches to Hi, Q5406 turns ON and
the charging circuit starts operating.
1-2. Power supply filter
L5401 and C5401 constitute the power supply filter. They
smooth out ripples in the current which accompany the switch-
ing of the oscillation transformer.
1-3. Oscillation circuit
This circuit generates an AC voltage (pulse) in order to in-
crease the UNREG power supply voltage when drops in cur-
rent occur. This circuit generates a drive pulse with a frequency
of approximately 50-100 kHz. Because self-excited light omis-
sion is used, the oscillation frequency changes according to
the drive conditions.
1-4. Oscillation transformer
The low-voltage alternating current which is generated by the
oscillation control circuit is converted to a high-voltage alter-
nating current by the oscillation transformer.
1-5. Rectifier circuit
The high-voltage alternating current which is generated at
the secondary side of T5401 is rectified to produce a high-
voltage direct current and is accumulated at electrolytic ca-
pacitor C5412 on the main circuit board.
1-6. Voltage monitoring circuit
This circuit is used to maintain the voltage accumulated at
C5412 at a constance level.
After the charging voltage is divided and converted to a lower
voltage by R5417 and R5419, it is output to the SY1 circuit
board as the monitoring voltage VMONIT. When this VMONIT
voltage reaches a specified level at the SY1 circuit board, the
CHG signal is switched to Low and charging is interrupted.
2. Light Emission Circuit
When RDY and TRIG signals are input from the ASIC expan-
sion port, the stroboscope emits light.
2-1. Emission control circuit
When the RDY signal is input to the emission control circuit,
Q5409 switches on and preparation is made to let current
flow to the light emitting element. Moreover, when a STOP
signal is input, the stroboscope stops emitting light.
2-2. Trigger circuit
When a TRIG signal is input to the trigger circuit, D5405
switches on, a high-voltage pulse of several kilovolts is gen-
erated inside the trigger circuit, and this pulse is then applied
to the light emitting part.
2-3. Light emitting element
When the high-voltage pulse form the trigger circuit is ap-
plied to the light emitting part, currnet flows to the light emit-
ting element and light is emitted.
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Beware of electric shocks.
