Sony TC-730 - System Control; Brake Solenoid PM602; Reel Motor Circuit; Pinch Roller Solenoid PM601

Bt
From power supply circuit
Q503
Q306 (0406)!
o UPLAY
S614
Muting circu
Collector voltage of Q505 rises for
sTopo PLAY
FF
a =p S103-2
about three seconds when the
meade switch is changed, and then
306 (Q406) turns ON.
D604
Fig. 7.
3. SYSTEM CONTROL
3-1. Brake solenoid PM602
When FWD button is pushed, S608 turns ON.
Then high voltage (about 170 volts dc) rectified by
D604 is applied to PM602 through S605. PM602 is
energized.
3-2. Reel motor circuit
The motor current flows as follows:
46 V or 80 V terminals of power transformer
——» $612 ———» R609 ————-contacts
of relay RY602-——— reel motors M2, M3
—» $610 ————~- 0 V terminal of power
transformer
3-3. Pinch roller solenoid PM601
When S602 is turned ON by solenoid PM602,
high voltage (about 170 volts dc) rectified by D604 is
applied to PM601 through S604. PM601 is energized.
Bt
To bias osc circuit
ral” V (in FWD mode)
OV lin REV mode)
RY601
Muting circuit
3-4. Solenoid operating voltage
Solenoids (for brake, pinch roller, and tape
direction) are energized by high voltage (about 170
volts dc) and kept energized by low voltage (about 30
volts dc).
3-5. S612
This switch supplies a high reel-motor-driving
voltage (80 volts ac) to make strong tape tension in a
starting moment, because of tape slack elimination.
When pressing FWD or REV button, $612 supplies
80 volts ac for about one second unitl pinch roller
solenoid PM601 actuates S612. After solenoid PM601
has actuated S612, S613 supplies 46 volts ac for
normal tape tension.