JPS5897996A - interface device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an interface device for electrically connecting the inside of a W-number device, and is capable of performing bidirectional control with a single connection cord. In component type sound equipment #,
For example, is there a remote control switch inside the amplifier and an input selector circuit that is switched by this switch? There are devices in which the output of the above-mentioned switch is transmitted to the record player via a connection cord to change the player's operating mode, but in this case it is possible to remotely control the player with the switch on the amplifier side. However, it was not possible to switch the input selector circuit provided on the amplifier side to the player position using the mode changeover switch provided on the player side. In order to perform such control in the opposite direction, there was a problem in that it was necessary to connect the amplifier and the player with two connection cords, and to perform bidirectional control via each connection cord. .

The present invention 8A solves these conventional problems and provides an interface device that allows bidirectional control with a single connection cord.

An example in which the present invention is applied to a component type acoustic device will be described below with reference to the drawings.

In Figure 1, 1,2il''j: 1st and 2nd devices, here 1 is the record player and 2 is the amplifier. 03 is the connection cord that connects the player 1 and the amplifier 2. 4 is a player drive circuit provided inside the player 1, and B and TR1 are - of the drive circuit 4.
Resistance circuit and transistor, sw, H that constitute i1K
This is a player start switch in a first switch circuit provided in the player 1. Note that the output of the transistor TR1 is inputted to, for example, a microconbeater or the like to perform a predetermined operation.

On the other hand, 6 is a second switch circuit provided in the amplifier 2, SW2 is a player start switch therein, and 6 is an IC having a multi-stage flip-flop driven by the second switch circuit 6. Switching circuit, 7I/'
i switching circuit 60 a selector switch for switching to the backup state; SW3 is a switch for selecting a player therein; 9 is a selector switch 87; second selector switch 5;
TR2 is a transistor connected in parallel with the transistor corresponding to the player position, 10 is a pull-up resistor, 11 is a switching circuit 6
Tuner, player, tape by output.

A selector circuit selects each input terminal 11a to 11di of the auxiliary input, 12 is a power amplifier that amplifies the output of the selector circuit 11, and 13 is a transistor TR3 connected between the upper ta second switch circuit 6 and the connection cord 30. A bidirectional control circuit is connected in parallel with the interface circuit 13, and 16 is a speaker connected to the power amplifier 12. The bidirectional control circuit 14 is composed of a series circuit of a capacitor C and a diode D, both ends of which are connected to the power supply 1B via pull-up resistors R2 and R3, and one end of the capacitor C is connected to an interface circuit. 13 (on the second switch circuit 6 side), and one end of the diode D is connected to the output side (on the connection cord 3 side) of the interface circuit 13 .

In addition, transistor TR2, selector switch SW3
This is provided to prevent the drive circuit 4 in the player 1 from operating when the player 1 is closed, and to prevent the undercurrent of the backup power source 7 of the switching circuit 6 from flowing out when the amplifier 2 is powered off.

In the above W, first, the case where the player 1 is operated from the amplifier 2 side will be explained. When the selector switch SW3 in the amplifier 2 is closed, the corresponding flip-flop in the switching circuit 6 is inverted, and its output switches the selector circuit 11 to the player position. In this state, the second
When the start switch SW2 in the switch circuit 5 is closed, the emitter of the transistor TR2 is grounded. As a result, the transistor TR of the interface circuit 13
The emitter of the player 1 is also grounded, turning on this transistor, and the lower end of the resistor circuit R4 of the player 1 is grounded via the connection cord 3. This is equivalent to closing the start switch SW1 in the player 1, the base of the transistor TR4 in the player 1 is grounded, this transistor TR4 is turned on, and the player 1 starts. At this time, the diode D of the bidirectional control circuit 14 is biased in the opposite direction, so it is in an off state, and the capacitor C is not charged. I- Therefore, at this time, k has no effect on the operation of the bidirectional control circuit 14ij.
Instead of closing the start switch SW2 when the switch 3 is closed, even if you suddenly close the start switch SW2 before closing the selector switch SW3, the transistor TR2 will be turned on and its collector will be at ground potential, so in effect the selector switch SW2 will be closed. It is equivalent to closing . Therefore, in this case as well, the switching circuit 6 operates and the selector circuit 11 can be switched to the player position.

Next, we will explain the case where the amplifier 2 side is operated from the player 1 (IllI).The start switch S of the player 1
When W1 is closed, transistor TR1 is turned on and player 1 starts. At this time, the cathode of diode D on the amplifier 2 side is grounded, so diode D turns on, and the potential at the connection point a between capacitor C and diode D goes from +V to zero V as shown in Figure 2 (a). As a result, b4 has an oV as shown in the 21st peak).
A descending pulse appears. Therefore, the emitter of the transistor TR2 is momentarily grounded, and this transistor TR2 is momentarily turned on to ground its collector at=0. Therefore, the selector switch SW
The state becomes equivalent to closing S, the flip-flop in the switching circuit 6 is reversed, and the selector circuit 11 is switched to the player position. Therefore, after operating the start switch SW in the player 1, b The selector circuit 11 can be automatically switched to the player position without operating the selector switch SW3 on the Zabza amplifier 2 side.

Note that at the moment when the start switch SW1 on the player 1 side is closed, a trigger pulse in the positive direction as shown in FIG. 2(b) appears at point b, but this has no effect on the operation of the device.

Also, when the power of player 1 is turned off, the potential at 8 points falls to the voltage divided by the power supply voltage, resistor R3, and resistor R1, but at this time, the trigger pulse appearing at point b is sufficiently small, so the switching The circuit 6 will not malfunction. Furthermore, even if the start switch SW is closed with the power of the player 1 turned off, the divided 'voltage is only dropped to zero, so the trigger pulse appearing at point b is sufficiently small in this case as well. The switching circuit 6 will not malfunction.

Furthermore, if there is no diode D and pull-up resistor R3, when the power of amplifier 2 is on and the power of player 1 is on, point b becomes 0V, aA+V, and a negative trigger pulse is applied to point b. occurs, and even if the base of the transistor TR2 is at zero level, the transistor TR2 is turned on and the switching circuit 6 malfunctions. In order to solve this problem, it is necessary to insert a diode Df to make point 8 and point b the same potential so that a negative trigger does not occur.

In this way, regardless of the presence or absence of the connection cord 3, malfunctions due to power on/off of the amplifier 2 side can be reliably prevented.

As described above, the selector (q path 11) can be switched to the player position on both the amplifier 2g1Il and the player 1 side, so the playback signal from the player 1 and the hearing amplification are transmitted via the selector circuit 11, power amplifier 12, and speaker 16. I can do things.

In the above example, a record player was explained, but it can be realized in the same way with a tape recorder's tape recorder and playback operation, and it can be applied to other devices as well, not limited to cabinet and sound equipment. Furthermore, the interface circuit 13 is not limited to transistors, but can also be configured by a combination of two inverters.

Furthermore, it goes without saying that the switching circuit 6 and the selector circuit 11 shown in FIG. 1 may be constructed by one IC.

As described above, according to the present invention, by simply adding a bidirectional control circuit with a simple configuration in parallel with the interface circuit,
0 that can bidirectionally control the first and second devices connected with one connection cord.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an example of the present invention; FIG. (b) is its operating waveform diagram. 10...Record player (first device), 2...
...Amplifier (second device), 3...φ, e11 connection cord, 4...φ, drive circuit, 6...2nd
switch, circuit, 60・e...switching circuit, 8...
・・Selector switch, 11・11@・0 selector circuit, 12・・・force amplifier in −, 13・・・e skewer interface circuit, 14・・・bidirectional control circuit,
16...Speaker, 5vv1...Fist, 1st
Switch, SW, ......second in the switch circuit of
switch 1r81 switch in path.

Claims (1)

[Claims] The first one connected via the connection hood. Equipped with a second device1. A first switch circuit for switching the operation mode of the first device is provided in the first device, and in the device @2,
an interface circuit; a second switch circuit that switches the operation mode of the first device via the interface circuit and the connection cord; and a second switch circuit that is controlled by the second switch circuit and switches the second device to a predetermined operation mode. and a bidirectional control circuit connected in parallel with the interface circuit, and the bidirectional control circuit is connected to a capacitor and a diode, both ends of which are connected to a power supply via a pull-up resistor. by connecting one end of the capacitor and one end of the diode to the input side and output side of the intern ace circuit, respectively, and switching the first switch circuit in the first device. An interface device in which a diode of the bidirectional control circuit is turned on and off, and a second control circuit in the second device is switched by a change in voltage across the capacitor due to the on/off of the diode.