JPH0555024U - Abnormality judgment circuit of converter - Google Patents

Abstract

(57) [Summary] [Structure] A switch is connected to the resistor R1 for abnormality determination connected to the output side of the converter, and the output voltage V1 of the converter is compared in the ON state and the OFF state of the switch. Accordingly, an abnormality determination circuit of the converter, which enables abnormality determination regarding the contact resistance Ro in the converter itself or the connection relationship thereof. [Effect] During normal operation, by setting the switch to the off state, the output voltage V1 based on the divided voltage of the conversion voltage Vo by the resistor R1 and the contact resistance Ro.
To the converter and the linearity of the converter due to the resistor R1 can be avoided, and at the time of abnormality determination, the switch is set to the ON state and its output voltage V
By comparing 1 with that in the OFF state, it is possible to determine the abnormality of the contact resistance Ro relating to the converter.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to various converters used for converting various events into electric quantities as a command system or a detection system in a wide range of control circuits and diagnostic circuits such as potentiometers and their connection relations. The present invention relates to an abnormality determination circuit improved so as to be able to perform abnormality determination, in particular, abnormality determination relating to its contact resistance.

[0002]

[Prior Art]

 Generally, as an abnormality determination for this type of converter, an abnormality determination regarding a fixed position such as a neutral position and an abnormality determination outside a valid range such as a disconnection or a short circuit are performed. In this case, as a means for determining an abnormality regarding disconnection, a method of connecting a pull-down or pull-up resistor R1 to the output side of the converter has been widely used as shown in FIG.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned prior art, when the converter itself or the contact resistance Ro in the connection relationship thereof becomes abnormal during operation and its value increases, the normal conversion voltage Vo of the converter becomes the above-mentioned. The voltage V1 divided by the resistor R1 and the contact resistance Ro is output as if it were a normal output voltage, which may cause a malfunction or the resistor R1 may be combined with the converter by a combined resistance. However, there is a drawback that it impairs its linearity. In addition, the above-mentioned related art does not have a function of determining abnormality of the contact resistance Ro. In view of such circumstances, the present invention solves the drawbacks of the prior art by a simple configuration, avoids the malfunction, and can maintain the linearity thereof, and the contact resistance Ro is abnormal or broken. It is an object of the present invention to provide a converter abnormality determination circuit capable of determining such as.

[0004]

Means for Solving the Problems In order to solve the above problems, the present invention connects a switch to a resistor for abnormality determination connected to the output side of a converter, and A technical means has been adopted in which the output voltage of the converter is compared to determine an abnormality regarding the contact resistance in the converter itself or in the connection relationship thereof.

[0005]

[Action]

 According to the present invention, by adopting the above technical means, the switch is set to the off state during the normal operation, so that the malfunction due to the voltage division by the resistor R1 and the linearity of the converter are caused. In addition to avoiding the failure of the contact resistance Ro, it is possible to determine the abnormality of the contact resistance Ro related to the converter by setting the switch to the ON state and comparing the output voltage V1 with that in the OFF state at the time of abnormality determination. it can.

[0006]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a conceptual diagram showing an essential part of the present invention, and is characterized in that a switch is connected to a resistor R1 for abnormality determination connected to the output side of the converter in terms of a circuit. In the figure, Vc, Vo, and V1 indicate the power supply, the normal conversion voltage, and the actual output voltage, respectively. FIG. 2 is a block diagram showing a case in which the present invention is applied to an actuator drive control circuit using a potentiometer as a converter. In the figure, reference numeral 1 denotes a command potentiometer, which corresponds to the converter which is the object of abnormality determination in the present invention. A microcomputer 2 is connected to the output side of the command potentiometer 1 through an A / D converter 3 for converting an analog signal into a digital signal. A drive circuit 4 is connected to the microcomputer 2, and the drive of the actuator 5 is controlled based on a command signal from the command potentiometer 1 via the drive circuit 4. ing. Further, a feedback potentiometer 6 is provided at an appropriate portion of the operating portion of the actuator 5, and the feedback signal thereof is fed back to the microcomputer 2 via the A / D converter 3. There is. The actuator drive control circuit is configured by these respective elements.

Next, the abnormality determination circuit, which is a feature of the present invention, will be described. In FIG. 2, R1 is a resistor for abnormality determination connected to the output side of the command potentiometer 1, S is an on / off switch thereof, and the abnormality determination circuit is constituted by these series circuits. .. The switch S is configured to be on / off controlled by the microcomputer 2. The output voltage V1 of the command potentiometer 1 is configured to be detected by a voltage detecting means (not shown). Then, during normal operation, the switch S is set to the off state in response to a command from the microcomputer 2. As a result, since the resistor R1 for abnormality determination is shut off, even if the contact resistance Ro in the connection relation between the command potentiometer 1 itself as a converter or the collector changes, the subsequent circuit That is, since the input impedance of the circuit after the A / D converter 3 is usually large, the output voltage V1 can output a value that substantially matches the normal conversion voltage Vo with almost no influence thereof. .. Therefore, the malfunction due to the voltage division by the resistor R1 as in the prior art is avoided. Further, as described above, in the normal operation, the resistor R1 is cut off, so that the linearity of the command potentiometer 1 is not impaired. Next, at the time of abnormality determination, the switch S is set to the ON state by the command of the microcomputer 2. Thereby, as the output voltage V1, the converted voltage Vo of the command potentiometer 1 is divided by the contact resistance Ro and the resistor R1, and the value is output by the switch S. Since the contact resistance Ro can be back-calculated by comparing with the value of the output voltage V1 in the off state, it is possible to easily determine the abnormality of the contact resistance in the command potentiometer 1 itself or the connection relation of the connector or the like. You can This abnormality determination work can be performed even while the command potentiometer 1 is operating, that is, while the conversion voltage Vo is changing. In this case, the switch S is temporarily turned on during the operation. It can be easily determined by comparing the value of the output voltage V1 at this time with the average value of the output voltage V1 in the OFF state immediately before and immediately after this switching. Further, in the case of disconnection, the abnormality determination can be easily performed by the pull-down function of the resistor R1 as in the conventional case. In the above description, the case where the command potentiometer 1 is the target of abnormality determination has been described, but the present invention is not limited to this, and for example, a resistor and a switch for abnormality determination are provided on the output side of the feedback potentiometer 6. When connected, it can be applied to various converters such as the same abnormality determination.

[0008]

[Effect of the device]

 As described above, the present invention can obtain the following effects based on the above configuration. (1) With a simple configuration, it is possible to easily determine whether the contact resistance of the converter itself or its connection is abnormal. (2) Moreover, fluctuations in the output voltage due to fluctuations in the contact resistance during normal operation of the converter can be greatly reduced. (3) Further, it is possible to avoid an obstacle to the linearity of the converter due to the abnormality determining resistor.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a main part of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a main part of a conventional technique.

[Explanation of symbols] 1 ... Potentiometer for command 2 ... Microcomputer 3 ... A / D converter 4 ... Drive circuit 5 ... Actuator 6 ... Feedback potentiometer Ro ... Contact resistance R1 ... For abnormality judgment Resistor S ... Switch Vc ... Power supply Vo ... Converted voltage V1 ... Output voltage

Claims (1)

[Scope of utility model registration request] 1. A converter connected to a resistor for abnormality determination connected to an output side of the converter, and comparing the output voltage of the converter in the ON state and the OFF state of the switch to thereby convert the converter. An abnormality determination circuit for a converter, which enables abnormality determination relating to contact resistance in itself or in its connection relationship.