Akai GX-260D

Vil. MECHANICAL OPERATING PRINCIPLES
PHASE CAPACITOR
“eee AC
> °
SUB COIL
Fig. 19
Fig. 20
TORQUE MOTOR
Refer to Schematic Diagram 1460813
1.
DIRECTION CHANGE OF MAIN MOTOR
REVOLUTIONS
By means of manual operation or sensing tape,
SW14, SW16 or sensing pole grounds the base of
TR1 or TR2 on the system control board, thus
facilitating or obstructing the lead through between
E-C of TR2 and changing Rev Relay contact point
RL1-3 as well as RL1-4 accordingly. This changes
the position of the main motor sub coil and phase
capacitor, and direction of the main motor revolu-
tions is reversed. (See Fig. 19). At this time, when
TR2 is turned on (Rev mode), the forward direction
voltage of Diode D2 1N34A is decreased, and this
low voltage is. utilized to lower the base voltage of
TR1, and TR1 is turned off. Thus, TR2 is held
at ON condition for operating function.
. TORQUE MOTOR SUPPLY VOLTAGE
Voltage is distributed by R3, 5W 3909 (at Fwd,
Rev) and R2, 10W, 45Q (at F.Fwd, Rwd) inserted
parallel with the supply side of the left and right
torque motors which are connected in series. (See
Fig. 20)
- FORWARD MODE
When the Fwd Button is depressed, this depresses
SW14, SW13.
SW14 turns OFF TR2 from Rev mode,. Reverse
Relay RL1 is turned OFF, and the direction of
main motor revolutions.as well as the voltage ‘dis-
tribution to the torque motor is changed.
When SW13 is depressed, AC 120V flows, to D8,
and then DC170 flows to SW13>SW2> PL2|> SW12>
SW3, Plunger PL2 is pulled, and SW2, SW4 and SW6
are activated.
When SW2 is turned ON, AC 25V flows to D6—>D7,
and then DC30.5V flows to SW2> [PL2] >SW12
>SW3, and PL2 is held by DC30.5V.
When SW4. is turned ON, AC120V flows to D8,
and then DC170V flows to SW5>SW18>SW4> PL3|>
SW12-SW3,. Plunger PL3 is pulled, and SWS is
activated.
When SWS is activated, AC 25V flows to D6~>D7,
and then DC30.5V flows to SW5~SW18-SW4>
+SW12>SW13, and Plunger PL3 is held by
DC30.5V.
When SW6 is activated, AC120V is supplied to the
Torque Motors, quick tension. SW8 connected to
the Pinch Wheel Lever works after a slight delay,
and AC100V passes resistors R1, R4 and is supplied
to the torque motors.
The purpose of the quick Tension Switch is to
prevent the tape transported from the capstan from
running roughly and unevenly, when the torque
motor is suddenly started from stopped condition.
The Quick Tension Switch works from Stop to Fwd
or Rev, but does not work to and from Fwd and
Rev.
. REV. MODE
When the Rev Button is depressed, SW16, SW15
are activated.
SW16 turns OFF TRI from Fwd mode, TR2 is
turned ON, RL1 is activated, and the direction of
the main motor as well as the voltage distribution —
to the torque motor is changed.
When RL1 is turned ON, contact point RL1-2 is
closed, AC120V flows to D8, and then DC170V
flows to SW1>RL1-2> [PL1]>SW3, and PL1 works.
When PL1 is activated, AC25V flows to D6-D7,
and then DC29.5V flows to SW1>RL1-2>[PLi|>
SW3, and PLI is held at ON condition.
The voltage applied to PL2, PL3 as well as the torque
motor, and the function of the Quick Tension
Switch etc. are the same as at Fwd mode.
. FAST FORWARD MODE.
When the OFF Button is depressed, SW13, SW18,
SW19, SW17 are activated.
When SW13 is depressed, Brake Plunger PL2 works
in the same way as at Fwd mode, SW18 functions
to prevent Pinch Wheel Plunger PL3 from working.
SW19 changes the voltage distribution to the torque
motor. ;
SW17 is mechanically held. The resistor inserted
parallel with the torque motor is changed to R2
10OW 452 by SW17.
. RWD MODE
When the Rewind Button is depressed, SW15, SW18,
SW19, SW17 are activated.
The function of these various switches are the same
as at Forward & at Forward mode.
. STOP MODE
At each mode the brakings work when the SW12
which is interlocked with the Stop Button is re-
leased, and PL2, PL3 and the respective switches
interlocked with these plungers are released.
18