JPH0229534Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Subject of the invention The present invention relates to a remote control circuit used in a cassette deck, etc., and particularly relates to a remote control circuit that does not cause malfunction when a remote control operating device, etc. is connected to a cassette deck, etc. .

(2) Purpose of the invention The invention aims to prevent erroneous inputs that occur when a remote control device, etc. is connected to a cassette deck, etc.
It is an object of the present invention to provide a remote control circuit that can distinguish between original input from a remote control operating device, etc., and prevent malfunctions.

(3) Contents of the conventional example and its drawbacks FIG. 1 is a circuit diagram showing a conventional remote control circuit, and FIG. 2 is a waveform diagram for explaining the operation of FIG. 1.

The configuration and operation of the remote control circuit shown in FIG. 1 will be explained below. The remote control circuit shown in FIG. 1 is divided into a remote control control circuit A and a remote control operation circuit B. The remote control control circuit A is connected as described below. An output terminal of a central processing unit (hereinafter referred to as CPU) 1 is connected to an input terminal of a digital-to-analog converter (hereinafter referred to as D/A converter) 2,
The input terminal of the CPU 1 is connected to the output terminal of the operational amplifier 3. The output terminal of the D/A converter 2 is connected to the inverting input terminal of the operational amplifier 3, and is also grounded via a resistor _R9 . The non-inverting input terminal of the operational amplifier 3 is connected to a resistor.
It is connected to the power supply terminal 6 via _R8 , and also to one end of the connection terminal 4 connected to the remote control operation circuit B. The other end of the connection terminal 4 is grounded.

The remote control operation circuit B is composed of a series circuit consisting of a plurality of resistors and a plurality of switches as described below. A resistor R 1, a resistor R ₂ , a resistor R ₃ , and a resistor are connected to the connection terminal 5 which is the connection part with the _remote control control circuit A.
A series circuit consisting of R ₄ , resistor R ₅ , resistor R ₆ , and resistor R ₇ is connected. The connection portion between the resistor R ₇ and the connection terminal 5 is designated as a. A connecting portion between the resistor R ₁ and the connecting terminal 5 and a connecting portion a are connected via a switch S ₁ , and the resistor R ₁ and the resistor R ₂
and a connection part a via a switch _S2 , and a connection part between the resistor _R2 and the resistor _R3 ,
A connection part a is connected through a switch _S3 , a connection part between the resistor _R3 and the resistor R4 is connected to a connection part a through a switch _S4 , and a connection part between the resistor R3 and the resistor _R4 is connected through a switch _S4 . Switch the connection part with R ₅ and connection part a with S ₅
A connecting portion between the resistor _R5 and the resistor _R6 and a connecting portion a are connected via a switch _S6 , and a connecting portion between the resistor _R6 and the resistor _R7 ; The connection part a is connected through the switch _S7 .

The operation of the remote control circuit shown in FIG. 1 will be explained below.

The CPU 1 outputs a 3-bit number in the order of (7, 6, 5, 4, 3, 2, 1, 0) ₁₀ in time series from an output terminal as a digital signal.
The digital signal is D/A by the D/A converter 2.
The converted output becomes a stepped voltage which is the reference voltage for comparison shown in Fig. 2 (however, E ₇ > E ₆ ... > E ₁
>E ₀ , E ₀ =0 [volt]. ) is input to the inverting input terminal of the operational amplifier 3. In the remote control operation circuit B, the switch
S ₇ , the switches S ₆ , . . . , and the switch S ₁ are closed by remote control operation to change the number of connections of the plurality of resistors R ₁ to _{R 7} configuring the series circuit, and to adjust the corresponding voltage. e ₇ , e ₆ ,…
The constants of _{the resistor} R ₇ , the resistor _{R 6 ,} .
..., _e1 is input to the non-inverting input terminal of the operational amplifier 3. The E ₇ shown in FIG. 2,
Stepped voltages E ₆ , ..., E ₁ , E ₀ and the above e ₇ ,
The relationship with the set output voltages e ₆ , . . . , e ₁ is as follows.

E ₇ ＞e ₇ ＞E ₆ ＞e ₆ ＞……＞e ₂ ＞E ₁ ＞e ₁ =E ₀ =0
[Volt] The output from the output terminal of the operational amplifier 3 is
Input to the input terminal of CPU1. The CPU 1 is
It is programmed to check the output from the output terminal of the operational amplifier 3 which is input to the input terminal of the CPU 1 every time the 3-bit digital signal is output from the output terminal of the CPU 1.

Here, the stepped voltages E ₇ , E ₆ , ..., E ₁ ,
Let E ₀ be E _A , and the set output voltage e ₇ , e ₆ , ..., e ₁
Let be e _B. For example, in the remote control operation circuit B, the voltage _e3 applied to the non-inverting input terminal of the operational amplifier ₃ when the switch S3 is closed, and the voltage e3 applied to the inverting input terminal of the operational amplifier 3, output voltage E ₇ of the D/A converter 2,
E ₆ , ..., E ₁ are compared in the operational amplifier 3,
The output signal is input to the input terminal of the CPU 1. Until the voltage E _A reaches the voltage E ₃ , e ₃ <E _A holds; however, when the voltage E _A reaches the voltage E ₂ , e ₃ >E _A =E ₂ and the operational amplifier 3 The output value from the output terminal changes, and the CPU 1 confirms the change.
This confirmation shows that the voltage e ₃ is between the voltage E ₃ and the voltage E ₂ and that the switch S ₃ of the remote control operation circuit B is closed, so the CPU 1 Said switch
S ₃ instructs the corresponding action. (However, the CPU
The portion where 1 indicates the operation corresponding to the switch _S3 is omitted from illustration in FIG. ) However, the remote control operation circuit B
When connecting to the remote control control circuit A, the connection terminal 4 is temporarily shorted, and the short circuit state is the same as when the switch S1 is closed, and the CPU ₁ is connected to the switch S1.
This has the disadvantage of causing a malfunction because it identifies that S ₁ is closed.

(4) Means for Solving the Problems In order to solve the above-mentioned problems, the present invention consists of a plurality of resistors and a plurality of switches, and corresponds to each remote control operation by operating each of the plurality of switches. a remote control operation circuit that sets and outputs a different voltage by changing the connections of the plurality of resistors; an operational amplifier that compares the set output voltage of the remote control operation circuit with a reference voltage for comparison; a central processing unit that outputs an output from an output terminal and inputs the output of the operational amplifier to an input terminal, and when the connection of a plurality of resistors of the remote control operation circuit is changed, the set output voltage of the remote control operation circuit is changed. The plurality of resistors are connected so that the voltage does not become 0 volts.

(5) Example of the invention An example of the invention is shown in Fig. 3. FIG. 4 is a waveform diagram for explaining the operation of FIG. 3.

The configuration and operation of the remote control circuit shown in FIG. 3, which is an embodiment of the present invention, will be described below. In the following description, the same parts as in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

It is divided into a remote control control circuit A and a remote control operation circuit C shown in FIG. The remote control operation circuit C is composed of a series circuit consisting of a plurality of resistors and a plurality of switches as described below.

A resistor R ₀ and a resistor R ₁ are connected to the connection terminal 5 which is the connection part with the remote control control circuit A.
A series circuit consisting of resistor R ₂ , resistor R ₃ , resistor R ₄ , resistor R ₅ , resistor R ₆ , and resistor R ₇ is connected.
The connection portion between the resistor R ₇ and the connection terminal 5 is designated as b. a connection portion between the resistor R ₀ and the resistor R ₁ ;
A connection part b is connected through a switch _S1 , a connection part between the resistor _R1 and the resistor R2 is connected to a connection part b through a switch _S2 , and a connection part between the resistor R1 and the resistor _R2 is connected through a switch _S2 . Switch the connection part with R ₃ and connection part b with switch S ₃
A connecting portion between the resistor _R3 and the resistor _R4 and a connecting portion b are connected via a switch _S4 , and a connecting portion between the resistor _R4 and the resistor _R5 ; Connection part b is connected via switch _S5 , and the resistor
The connecting portion between _R5 and the resistor _R6 and the connecting portion b are connected via a switch _S6 , and the connecting portion between the resistor _R6 and the resistor _R7 and the connecting portion b are connected via a switch _S7. Connect via.

The operation of the embodiment of the present invention shown in FIG. 3 will be described below. The CPU 1 converts a number consisting of 3 bits in chronological order (7, 6, 5, 4, 3, 2,
1, 0) Output from the output terminal as a digital signal in the order of ₁₀ . The output obtained by D/A converting the digital signal by the D/A converter 2 becomes a stepped voltage which is a reference voltage for comparison shown in FIG.
E ₇ >E ₆ >...>E ₁ >E ₀ , E ₀ >0 [volt]. ) is input to the inverting input terminal of the operational amplifier 3. In the remote control operation circuit C, the switch S ₇ , the switch S ₆ , . . .
By remote control operation of closing each switch of the switch S ₁ , the number of connections of the plurality of resistors R ₀ to R ₇ forming the series circuit is changed, and the corresponding voltages e ₇ , e ₆ , ..., e _{1 are} changed. The constants of the resistor R ₇ , the resistor _{R 6} , . _. . , and the resistor _{R 1} are determined so as to set and output The output voltage is input to the non-inverting input terminal of the operational amplifier 3. The stepped voltages E ₇ , E ₆ , ..., E ₁ , E ₀ shown in FIG. 4 and the set output voltages e ₇ , e ₆ , ..., e ₁ have the following relationship. There is.

E ₇ >e ₇ >E ₆ >e ₆ >...>e ₂ >E ₁ >e ₁ >E ₀ >0 The output from the output terminal of the operational amplifier 3 is
Input to the input terminal of CPU1. The CPU 1 is
It is programmed to check the output from the output terminal of the operational amplifier 3, which is input to the input terminal of the CPU 1, each time the 3-bit digital signal is output from the output terminal of the CPU 1.

Here, the stepped voltages E ₇ , E ₆ , ..., E ₁ ,
Let E ₀ be E _C and the set output voltage e ₇ , e ₆ , ..., e ₁
Let be e. For example, when switch _S3 is closed,
the voltage e ₃ applied to the non-inverting input terminal of the operational amplifier 3; and the output voltages E ₇ , E _{6 ,} and output voltages of the D/A converter 2 applied to the inverting input of the operational amplifier 3;
..., E ₁ , E ₀ are compared in the operational amplifier 3,
The output signal is input to the CPU 1. Until the voltage E _C reaches the voltage E ₃ , e ₃ <
However, when the voltage E _C becomes the voltage E ₂ , e ₃ >E _C = E ₂ , the output value from the output terminal of the operational amplifier 3 changes, and the CPU 1 confirms the change _. .
This confirmation shows that the voltage e ₃ is between the voltage E ₃ and the voltage E ₂ and that the switch S ₃ of the remote control operation circuit C is closed. Switch S ₃
Instruct the corresponding action. (However, the CPU1
However, illustration of the portion instructing the operation corresponding to the switch _S3 is omitted in FIG. ) When connecting the remote control operation circuit C to the remote control control circuit A, the connection terminal 4 is temporarily short-circuited. However, in this embodiment, the voltage value e ₁ corresponding to the switch S ₁ is e ₁ >0 [volt], and the output voltage of the D/A converter 2 is E ₇ >E ₆ >E ₅ ＞……E ₂ ＞E ₁ ＞E ₀ ＞0,
The non-inverting input of the operational amplifier 3 whose level is lower than the voltage E ₀ is not determined by the CPU 1 .

In the above embodiment, the case where the resistor R ₇ has a finite resistance value has been described, but the resistance value of the resistor R ₇ may be an infinite impedance (open state).

(6) Effects of the invention As described above, according to the invention, it is possible to prevent malfunctions that occur when connecting a remote control operation section, etc. to a remote control control section, etc.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional remote control circuit, FIG. 2 is a waveform diagram for explaining the operation of the circuit in FIG. 1, FIG. 3 is a circuit diagram showing an embodiment of the present invention, and FIG. The figure is a waveform diagram for explaining the operation of the circuit of FIG. 3. 1... CPU, 2... D/A converter, 3... operational amplifier, 4, 5... connection terminal, 6... power supply terminal, R ₀ , R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ ... Resistance, S ₁ , S ₂ , S ₃ , S ₄ , S ₅ , S ₆ , S ₇ ... Switch,
A...Remote control control circuit, B, C...
...Remote control operation circuit.

Claims (1)

[Claims for Utility Model Registration] Consisting of a plurality of resistors and a plurality of switches, the connection of the plurality of resistors is changed in response to each remote control operation by each switch operation of the plurality of switches, and different voltages are set and output. an operational amplifier that compares a set output voltage of the remote control operation circuit with a comparison reference voltage; an operational amplifier that outputs the comparison reference voltage from an output terminal, and an output terminal of the operational amplifier that outputs the comparison reference voltage from an output terminal; and a central processing unit for input, and the plurality of resistors are connected so that when the connection of the plurality of resistors of the remote control operation circuit is changed, the set output voltage of the remote control operation circuit does not become 0 volts. A remote control circuit featuring: