Circuit Description - Sharp RT-203H Service Manual

RT-203H(S)
© CIRCUIT DESCRIPTION
SYNCHRONOUS START CIRCUIT
When the unit is in the dubbing mode in which the record-
ed contents of Deck 1 are copied into Deck 2, the syn-
chronous start circuit works to enable both Deck 1 and
Deck 2 to start their operations simultaneously.
Circuitry Behaviors
When the record button of Deck 2 is pushed while the
dubbing source selector switch SW5 is set at TAPE
1/MIC-MIX position, the power is applied via the
record/playback switch SW1-B to Q507 to turn it on; the
turn-on time of Q507 is decided by the time constant of
C507. With Q507 turned on, Q501 turns off so that the
motor M2 of Deck 2 stops to get Deck 2 in the record
standby mode.
When the play button of Deck 1 is then pushed, the
muting switch SW11 turns on and the base of Q507 is
grounded. With Q507 turned off, 'Q501 turns on so that
the motor M2 of Deck 2 is allowed to rotate to put Deck
2 in the record mode. In this way, Deck 2 gets in the
record mode simultaneously when Deck 1 is put in the
playback mode by pushing its play button.
LINE {
DSOI
swil
peck! DE PU MAIN
MUTING
Figure 8—1
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