JPS6037963B2 - repeat performance circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a repeat performance circuit for a chord player, and in particular, the record performance does not start immediately after the repeat switch is operated, and the repeat performance mode is ensured after the record performance ends. Furthermore, if the start/cut switch is operated while a record is playing, the repeat operation is cleared, and the repeat operation is cleared by operating the start/cut switch when the record starts playing. It is designed so that nothing happens.

Hereinafter, a detailed description will be given with reference to embodiments shown in the drawings.

M, is a motor for rotating the turntable, and M2 is a motor for rotating the tone arm. S, S2 are drive switches for the motor M, and these switches S, S2 are controlled by a cam 1 (see Figure 2) that rotates in response to the rotation of the tone arm rotating motor M2. . That is, FIG. 2A shows a state in which the tone arm is in the armrest position, and at this time, the switch S is in the on state and the switch S2 is in the off state. Figure 2B shows a performance state in which cam 1 is rotated half a turn by the motor and the tone arm is moved toward the record; at this time, switch S is in the off state and switch S2 is in the on state. . When the start/cut switch S3 is first operated, a trigger pulse as shown in FIG. 3A is generated at point A.

This trigger pulse is applied to the starting circuit 2 of the motor M. The starting circuit 2 includes an OR gate 3, a monostable multipipulator 4 (a metastable period product), and transistors 5 and 6. The trigger pulse is input to the monostable multipipelator 4 through the gate 3, and the output of the monostable multipipelator 4 is at a high level for a period T (see the beginning of FIG. 3). This high level output causes transistor 5,
6 is turned on, and the motor base starts rotating. The cam 1 rotates in response to the rotation of the motor base, and the switch S2 is switched from an off state to an on state. Therefore, since the drive circuit for the motor M2 is constituted by the switches S2 and S in the closed state, the rotation of the motor base continues even if the operation of the switch S3 is released at this point. Further, the switch S2, which is in the open state, also closes the drive circuit for the motor M, and the turntable (not shown) also rotates. When the cam 1 rotates approximately half a turn (see Fig. 2B), the switch S,
is turned off and rotation of motor M2 stops. At this point, the tone arm has moved to the playing position,
Further, since the switch S2 remains closed and the motor M continues to rotate, the record playing state is established. When the record has finished playing, the switches S,
is closed.

For example, after a record has finished playing, the tone arm will scan a silent groove with a coarse pitch, and the rotation angle of the tone arm per turn of the record will increase, so this will be detected and the detection lever will be activated. The switch S. is moved within the locus of the rotation needle provided on the lower surface of the turntable, and the detection lever is rotated by the rotation needle. It is sufficient to adopt a configuration that opens the following. Such a configuration is, for example, disclosed in Jitsukki No. 54-76706. When switch S, is closed, the drive circuit for motor M2 is closed, thereby causing cam 1 to rotate, and in response to the rotation of cam 1, switch S is subsequently closed continuously. When the cam 1 rotates approximately half a turn and returns to the initial position shown in FIG. 2A, the switch S2 is opened and the drive circuits for the motors M and 2 are opened. In response to the second half rotation of the cam 1, the tone arm is returned to the armrest base. By the way, in order to perform a repeat performance, it is sufficient to first operate the repeat switch S4.

When the repeat switch S4 is operated, the flip-flop (hereinafter abbreviated as F.F) 7 is triggered, and the Q output becomes a high level and the Q output becomes a roll level. The transistor 8 is turned on by the Q output, and the light emitting diode 9 lights up to indicate that the repeat operation is in progress. That is, F.
F7 serves as a storage means for storing the operation of the repeat switch S4. Now, before starting to play a record, when the separate tone arm is in the armrest position, the switch S2 is in the off state as described above, so the point B is at a low level, and the power supply voltage Vcc is applied to the point C via the resistor R2. is being applied, so point C is at a high level. Therefore, even if the Q output is at a low level, the output of the NOR gate 10 will never go to a high level. That is, the inconvenience that the starting circuit 2 is triggered in response to the operation of the repeat switch S4 and the record performance is started does not occur. Repeat switch S
As described above, if the start/cut switch S3 is operated after the operation of step 4, the record playing state is entered.

By the way, the trigger pulse generated at point A in response to the operation of the start/cut switch S3 is also applied to the monostable multipipetrator 11, so that the output of the monostable multipipelator 11 remains only for the duration of the monostable period.・The level becomes high (see Figure 3 C). After the switch S2 is turned on and the point B reaches the level, the time constant circuit 12 (resistor R, capacitor C,
If the time L required for the output (point ○) of Therefore, both of the two inputs of the AND gate 13 will not be at the level (the third
(See Figure C, 2), F. F7 is not cleared. Now, when the record playing is finished, the switch S is closed and the motor M2 starts to drive, and as the tone arm returns to the armrest base, the switch S2 is opened and the motor M,
, as explained earlier, the rotation of the earth stops.
By the way, when the switch S2 is opened, the potential at the point B decreases, and the potential at the connection point C between the resistor R2 and the capacitor C2 changes as shown in FIG. Therefore, during the period L during which the potential at point C maintains the trigger level of the NOR gate 10, Q
Since the output is also at low level (see FIG. 3, D), both of the two inputs of the NOR gate 10 become low level, and the output E becomes the /.-I level (see FIG. 3, H). Operate switch S3 using this E output. The starting circuit 2 is driven in the same manner as in the case of the above. Therefore, repeat performance is started. That is, the NOR gate 10, the resistor R2, and the capacitor C2 constitute a repeat performance setting means 14. On the other hand, while the record is playing, the start/switch S
3, the trigger pulse drives the starting circuit 2, the motor base starts rotating, the tone arm returns to the armrest position, and the record playing ends. At this time, the trigger pulse causes the monostable multipipulator 11 to
is also driven and its output becomes the /. level (see Figure 3, C), but since the point D of the time constant circuit 12 is already at the high level while the record is being played (see Figure 3, 2).
Both of the two inputs of the AND gate 13 become high level, and its output F becomes high level. This high level output causes the F. F7 is cleared. Therefore, after the record is finished playing,
However, it does go into repeat play mode. That is, the monostable multipipulator 11 constitutes a repeat operation clearing means, and the time constant circuit 12 constitutes an F. It constitutes a malfunction prevention circuit that prevents F7 from being cleared. According to the present invention described above, the IJ beat performance setting means for closing the motor starting circuit is responsive to the output of the storage means for storing the operation of the repeat switch and the return of the tone arm to the armrest position. Since the motor is driven in response to the switching output of the drive switch for the motor, which is controlled by This allows the user to reliably transition to a repeat performance state later.

Furthermore, the repeat operation clearing means automatically cancels the repeat operation when the start/cut switch is operated while the record is playing, and the repeat operation is cleared by the start/cut switch when the record starts playing due to the malfunction prevention circuit. There is no inconvenience of being rejected.

Brief Description of the Drawings Figure 1 is a wiring diagram of a record playing circuit according to the present invention, Figure 2 is a diagram showing the relationship between a cam and a switch,
FIG. 3 is an operating waveform diagram.

2 is a starting circuit, 7 is a storage means (flip-flop circuit)
, 11 is a repeat operation clearing means (monostable multipipelator), 12 is a malfunction prevention circuit (time constant circuit), 14
is a repeat performance setting means, S,, S2 is a drive switch,
S3 is a start/cut switch, S4 is a repeat switch, M is a turntable rotation motor, and M2 is a tone arm rotation motor.

Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A storage means for storing the operation of the repeat switch, a starting circuit for the tone arm rotation motor that is closed in response to the operation of the start/cut switch, and a starting circuit for the tone arm rotation motor that is closed in response to the operation of the start/cut switch; closing the starting corridor in response to a drive switch for a motor for rotating the tone arm and a switching output of the drive switch that is controlled in response to the output of the storage means and the tone arm returning to the armrest position; repeat performance setting means; repeat operation clearing means for clearing the storage means in response to the operation of the start and cut switch during record play; A repeat performance circuit comprising a malfunction prevention circuit for preventing clearing of the storage means.