JP2560733B2 - Bidirectional 2-wire remote control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bidirectional two-wire remote control (remote control) device used when operating a main body device from a distant place in an audio device or the like. .

"Prior Art" Conventionally, as a bidirectional multi-line remote control device which performs input / output via a remote control cable, a configuration shown in Fig. 3 is known. In this figure, 1 is a main unit 2
And a remote control box (operation unit) connected via a remote control cable 3 to the remote control box 1 for displaying a switch S for operating the main body device 2 and an operating state of the main body device 2. And the light emitting diode L of. One end of the switch S is connected to the controller 6 of the main unit 2 via the input line 3A of the remote control cable 3.
It is led to the input terminal IN of and is pulled up. Further, one end of the light emitting diode L is led to the output end OUT of the controller 6 of the main body device 2 via the output line 3B of the remote control cable 3. Further, the other ends of the switch S and the light emitting diode L are commonly connected to each other, guided to the main body device 2 through the common line 3C of the remote control cable 3, and grounded. Then, the controller 6 of the main body device 2 turns on / off the switch S by the voltage applied to its input terminal IN.
The off state is detected, and the light emitting diode L is on / off controlled by the voltage output from the output terminal OUT.

In such a bidirectional multi-wire remote control device, since the parallel transmission format is used, the same number of input lines as the switches S are used.
3A, the same number of output lines 3B as the light emitting diodes L, and one common line 3C are required. As a result, the number of lines of the remote control cable 3 increases as the number of switches S and light emitting diodes L increases. Is inevitable. Further, each wire 3A, 3B, 3C of the remote control cable 3 has a polarity and has a polarity, so that the wiring is troublesome.

Therefore, conventionally, as shown in FIG. 4, a bidirectional two-wire remote control device is known in which a microcomputer (hereinafter, abbreviated as a microcomputer) is used to exchange data by serial transmission. In this figure, the display data output from the microcomputer 10 on the main unit 9 side is the transmission circuit 11
After being converted into a serial signal by, it is transmitted to the remote control box 13 side via the two-wire remote control cable 12,
After being depolarized by the diode bridge 14, it is converted into the original parallel display data by the transmission circuit 15 and supplied to the microcomputer 16. Then, the microcomputer 16 controls ON / OFF of each of the light emitting diodes L ₁ and L ₂ based on the supplied display data. On the other hand, the microcomputer 16 on the remote control box 13 side detects the on / off state of the switches S ₁ and S ₂ ,
The detection data is output. Then, this detection data is converted into a serial signal by the transmission circuit 15 and then transmitted to the main body device 9 side through the diode bridge 14 and the remote control cable 12, and then the transmission circuit 11 transmits the original parallel detection data. And is supplied to the microcomputer 10. As a result, the microcomputer 10 detects the on / off state of the switches S ₁ and S ₂ based on the supplied detection data.

[Problems to be Solved by the Invention] By the way, in the above-described bidirectional two-wire remote control device using the microcomputer, the remote control cable 12 can be a non-polar two-wire system, but the remote control box 13 Since the transmission circuit 15 and the microcomputer 16 have to be provided inside, there is a problem that the configuration of the device becomes complicated and large, and the cost becomes high.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a bidirectional two-wire remote control device capable of depolarizing a remote control cable with an extremely simple and compact structure.

"Means for Solving Problems" An operation unit provided with at least one or more switch means and display means is connected to a main body device via a two-wire cable, and the main body device side operates the switch means. In the bidirectional two-wire remote control device for detecting the state and controlling the lighting operation of the display means, a current flowing between two wires of the cable is supplied to the operation section side in accordance with the operation of the switch means. Current changing means for changing and display operation control means for controlling the lighting operation of the display means based on the voltage change between the two wires of the cable are provided, while the main body device side is lit by the lighting of the display means. 2 of the cable according to the control signal for controlling the operation
It is characterized in that a voltage varying means for changing the voltage between the lines and a switch state detecting means for detecting the operating state of the switch means based on the change in the current flowing between the two lines of the cable are provided.

[Operation] When the switch means on the operation unit side is operated, the current varying means changes the current flowing between the two wires of the cable, and the switch state detecting means on the main body device side operates the switch means based on the change in the current. Detect the condition. On the other hand, when the voltage varying means on the main body device side changes the voltage between the two wires of the cable according to the control signal for controlling the lighting operation of the display means, the operating unit is based on the voltage change between the two wires of the cable. The display operation control means on the side controls the lighting operation of the display means.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention. In this figure, 20 is a main unit, 21 is a remote control box, and these are 2-wire type remote control cables 12
Connected through. The main unit 20 has a microcomputer 22
And a transistor Tr which is turned on / off by the microcomputer 22. When this transistor Tr is turned on, the voltage + Ah applied to its emitter
Is applied to one input end 14A of the diode bridge 14 provided in the remote control box 21 through the resistor RZ for preventing overcurrent and the signal line 12A of the remote control cable 12, and this transistor Tr is When turned off, the voltage applied to the anode of the diode DL + Vl (<+ Vh)
Through the resistor RZ and signal line 12A
Is applied to the input terminal 14A of. This diode bridge 14
The other input terminal 14B of is the signal line 1 of the remote control cable 12.
It is led to the main body device 20 via 2B, is grounded via the resistor Rd, and is led to the input end of the comparator 27. The comparator 27 compares the potential of the input end 14B of the diode bridge 14 with the reference voltage divided by the resistors Ra and Rb. The comparison result is a microcomputer.
It is supplied to the input terminal IN of 22.

On the other hand, the voltage output from the output terminals 14C and 14D of the diode bridge 14 in the remote control box 21 is between the both ends of the circuit formed by connecting the switch S and the resistor R in series,
A light emitting diode L, a resistor Rc, and a constant voltage diode ZD are connected in series across a circuit. In this case, the cathodes of the light emitting diode L and the constant voltage diode ZD are connected through the resistor Rc, and when the applied voltage from the diode bridge 14 is + Vh, the light emitting diode L is turned on and the applied voltage is The values of the resistor Rc and the constant voltage diode ZD are appropriately set so that they are turned off when the voltage drops to + Vl.

In the above configuration, when the microcomputer 22 of the main unit 20 turns on the transistor Tr, the transistor Tr and the resistor
Input 1 of diode bridge 14 via RZ and signal line 12A
A voltage of + Vh is applied to 4A, which causes the light emitting diode L to light up. When the microcomputer 22 turns off the transistor Tr, the voltage applied to the input end 14A of the diode bridge 14 becomes + Vl, which turns off the light emitting diode L.

The resistor R connected in series with the switch S is for adjusting the current flowing through the switch S, and its resistance value is relatively small.
Is turned on, a predetermined current flows through the switch S and the resistor R, and this predetermined current value is
It is converted into a voltage by the resistance Rd on the side.

Here, the applied voltage to the diode bridge 14 is +
The current value when the switch S is on at Vh is I ₁ , the current value when the applied voltage is + Vl and the switch S is on is I ₂ , and the current value when the applied voltage is + Vh and the switch S is off is I ₃ , when the switch S in applied voltage + Vl is the current value in the case of off-set to I _4, the relation of I _1> I ₂ and I _3> I ₄ is always kept,
If the resistance of each part is set so that I ₂ > I ₃ , I ₁ >
The relationship of I ₂ > I ₃ > I ₄ holds. Then, when the current value is I ₂ or more, the output of the comparator 27 becomes “H” level, and when the current value is I ₃ or less, the output of the comparator 27 becomes “L” level. If the "H" level signal is supplied to the input terminal IN, the microcomputer 22 detects that the switch S is turned on.

If the resistance value cannot be set so that I ₂ > I ₃ , an A / D converter is provided instead of the comparator 27, and the above current values I _{1 to} I ₄ are stored in advance in the memory of the microcomputer 22. The stored data may be stored so that the on / off state of the switch 4 is determined by a program by software.

The first embodiment described above is the most basic configuration of 1 input / 1 output, but by applying the same principle as this,
A multi-input / multi-output remote control device as shown in FIG. 2 can be realized.

FIG. 2 is a diagram showing the configuration of the second embodiment of the present invention. In this figure, the display data output from the microcomputer 31 of the main body device 30 is converted into an output voltage Vout by the D / A converter 32, and this output voltage Vout is sent to the remote control box 34 side via the remote control cable 12. It is supplied to the LED control circuit 35 via the diode bridge 14. The LED control circuit 35 controls lighting of the n light emitting diodes L _{1 to} Ln based on the supplied output voltage Vout. Further, the remote control box 34 is provided with m switches S _{1 to} Sm and resistors R _{1 to} Rm for adjusting currents flowing through these switches S _{1 to} Sm.
When each of the switches S _{1 to} Sm is turned on / off, the current flowing through each of the switches S _{1 to} Sm and the resistors R _{1 to} Rm changes, and this current change is provided on the main device 30 side. It is converted to a voltage by the resistor Rd and A / D
The signal is input to the converter 33, further converted into a digital signal by the A / D converter 33, and supplied to the input terminal IN of the microcomputer 31. The memory inside this microcomputer 31 contains each light-emitting diode.
Data regarding the input voltage Vin obtained corresponding to the on / off combinations of L _{1 to} Ln and the switches S _{1 to} Sm is stored as a table. The microcomputer 31 is by reference to the basis of this table to the input voltage Vin, so as to determine the respective switches S ₁ -Sm ON / OFF software manner. For example, the light emitting diode L ₁
When L and L ₂ are lit, and the input voltage Vin has a specific value, it is determined that the switch S ₂ is on.

[Advantages of the Invention] Current varying means for changing the current flowing between the two wires of the cable on the operation unit side according to the operation of the switch means, and the lighting operation of the display means based on the voltage change between the two wires of the cable. And a voltage changing means for changing the voltage between the two lines of the cable according to a control signal for controlling the lighting operation of the display means. Since the switch state detecting means for detecting the operating state of the switch means based on the change in the current flowing between the two wires of the cable is provided, the bidirectional two-wire system for transferring data by serial transmission using the conventional microcomputer. As compared with the remote control device, it is possible to obtain the effect that the cable can be made non-polarized by an extremely simple and compact structure.

[Brief description of drawings]

1 is a circuit diagram showing the configuration of the first embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of the second embodiment of the present invention, and FIG.
FIG. 4 is a circuit diagram showing a configuration of a conventional bidirectional multi-wire remote control device, and FIG. 4 is a circuit diagram showing a configuration of a conventional bidirectional two-wire remote control device. 12 …… Cable, 12A, 12B …… Signal line, 14 …… Diode bridge, 21,34 …… Remote control box (operation part), 20,30 …… Main unit, 22,31 …… Microcomputer, L, L _{1 to} Ln ... Light emitting diode (display means), S, S ₁
~ Sm …… Switch (switch means), R, R ₁ ~ Rm …… Resistance, Tr …… Transistor, DL …… Diode, Rc, Rd…
… Resistance, ZD …… Voltage diode, 27 …… Comparator, 32 …… D / A converter, 33 …… A / D converter, 35 …… LED control circuit.

Claims (1)

(57) [Claims] 1. An operating section provided with at least one or more switch means and a display means is connected to a main body apparatus via a two-wire cable, and the main body apparatus side detects the operating state of the switch means. In the bidirectional two-wire remote control device for controlling the lighting operation of the display means, on the operation section side, a current varying means for changing a current flowing between two wires of the cable according to an operation of the switch means. And a display operation control means for controlling the lighting operation of the display means based on a voltage change between the two lines of the cable, while the main body device side controls the lighting operation of the display means. Voltage varying means for changing the voltage between the two wires of the cable according to the control signal of
A bidirectional two-wire remote control device comprising: a switch state detecting means for detecting an operating state of the switch means based on a change in a current flowing between the lines.