THORENS PC 650 - Page 12

PLAY
Fast Forward
Fast Rewind
Operation proceeds in a similar manner to STOP when the contact S 105 is closed
Since switching occurs over R 1748, PLAY cannot be activated when T 1705 has
been brought into conduction through the RECORD function (see RECORD”).
The PLAY command 1 appears at connection S 1717.
Operation proceeds in a similar manner to STOP when the contact S 107 is closed
The Fast Forward command 1 appears at connection S 1719.
Operation proceeds in a similar manner to STOP when the contact S 106 is closed
The Fast Rewind command 1 appears at connection S 1720.
If the MEMORY button is engaged, the positive voltage on S 1720 is conducted
to C 143 when the counter position 000 is reached, thus bringing T 119 briefly
into conduction and initiating the STOP function.
Tape Transport Stop The motion of the cassette is terminated at the end of the tape or through a
Function Indicators
STOP or PAUSE command by the Tape Transport Stop circuitry.
During normal operation in the PLAY (or RECORD) mode or during Fast For-
ward or Rewind, voltage pulses are delivered from the Power Control Board
VM 14 through connection S 1714 and are amplified by T 1707. Rectification
and voltage doubling is then performed with D 1751 and D 1752. The resulting.
positive voltage on the cathode of D 1752 brings T 1708 into conduction, turning
T 1709 off. No stopping function is initiated.
At the end of the tape, the reel motor stalls, and thus the voltage pulses disappear
on S 1714. T 1708 is turned off, T 1709 turned on. The collector voltage of
T 1709 consequently falls to nearly O V, extinguishing a Fast Forward command
1 on connection S 1719 through D 1749 or a Fast Rewind command 1 on S 1720
through D 1740. The absence of a command 1 causes the motor to be turned off
on VM 14. The command 0 also appears on S 1718, causing the holding magnet
(engaged during the PLAY mode) to be released (VM 14). Turning off T 1708
allows the base of T 1712 to be pulled toward +12 V. T 1712 conducts, turning
on the blinker circuit (T 1710, T 1711) to feed the STOP button LED.
If the STOP or PAUSE function has been initiated by closing a button contact or
the MEMORY switch, any Fast Forward, Fast Rewind, or PLAY command 1 will
be extinguished, stopping the reel motor and releasing the holding magnet. When,
however, the STOP or PAUSE function has been initiated in this way, the base
of T 1704 is pulled toward 0 V over D 1744 or D 1743, returning T 1708 to the
conducting state and thus preventing a blinking STOP indication.
During the time that the PLAY, Fast Forward, or Fast Rewind button is being
pressed, the potential of 0 V atD 1747, D 1748, or D 1741 turns on T 1704 to
prevent the cassette from stopping during run up.
With the exception of STOP, a command 1 on any of the buses is fed to the
corresponding NOT element in IC 1705, causing the appropriate LED function
indicator to illuminate.