JPS6156516A - Analog-to-digital converter - Google Patents

Abstract

PURPOSE:To save the labor for measurement with reduction of number of component parts and to improve the characteristics of conversion output, by converting analog signals into digital signals with start of a converter itself and also converting this digital signal into another digital signal having the optional characteristics that are not affected by the characteristics of the analog input signal. CONSTITUTION:An automatic start signal E is delivered from an automatic start signal generating means 5 as soon as the power supply of an A/D converter 1 is switched on. Then an automatic start signal generating means 6 is actuated and an input conversion means 3 is started by a self-start signal F. An analog signal A1 delivered from a position detector 8 having the nonlinear input/output characteristics is converted directly into a digital signal D1 having the nonlinear characteristics and supplied to a data conversion means 4. At the same time, a conversion end signal G is outputted from the means 3. The means 4 holds the input signal D1 and also converts it into a digital signal D2 having characteristics which are not affected by the characteristics of the signal A1. Then the signal D2 is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an analog-to-digital conversion device for converting an analog signal output from a detection device or the like that detects position, temperature, etc. into a digital signal.

(Prior art) As a conventional example of this kind of analog-to-digital converter, there is one as shown in FIG. 11, and analog/digital conversion means 12 (hereinafter referred to as A/D conversion means) that converts the analog signal A into a digital signal and outputs the digital signal to the outside.
, a manual activation means 13 that generates a activation signal S by pressing a push button, etc., and a conversion signal U is converted into the A/D conversion means by the activation signal S or an external signal T such as a data acquisition signal from an external device. The conversion signal generating means 14 outputs a converted signal to

In this analog-to-digital conversion device, an analog signal A output from a detection device 15 such as a position detection device is converted into a digital signal. The operation is performed as follows. First, in the first conversion, a start signal S is generated from the manual start means 13 by the push button operation by the measurer, and a conversion signal U is generated from the conversion signal generation means 14 according to the start signal S, and the A/D conversion means This is done by operating 12. 6. By doing this, the analog signal At-A/D input and held in the input holding means 11
The conversion means 12 converts it into a digital signal, and outputs this digital signal to the outside. Conversion from the next time onwards is performed by an external signal TK such as a data take-back signal input from an external device to the conversion signal generation means 14 via a predetermined component.
This is carried out by operating the conversion signal generation means 14 and operating the A/D conversion means 12 using the conversion signal U output from the conversion signal generation means 14. Therefore, the first conversion by the conversion means 12 is activated by the push button operation by the measurer, and the second and subsequent conversions are activated by the external signal T from an external device.

(Problems to be Solved by the Invention) However, in the case of such a conventional analog-to-digital conversion device, the conversion in the A/D conversion means 12 is activated by a push button operation by the measurer, This must be done using an external signal TK that is input from an external device through a predetermined part.This requires switching operations by the measuring person and the use of predetermined parts, which does not save labor and reduces the number of parts. In addition, since the A/D conversion means 12 simply converts the analog signal A into a digital signal DK and outputs it, the detection device 15 When the detection device 15 has a nonlinear input/output characteristic with respect to the quantity
The analog signal A with non-linear characteristics output from the A/D
The conversion means 12 converts the signal directly into a digital signal and outputs it. Therefore, there is a problem that the relationship between the detected quantity in the detection device 15 and the converted digital signal is non-linear, and the converted digital signal is influenced by the input/output characteristics of the detection device @150. Ta.

The present invention was made in order to solve the problems of the prior art, and its purpose is to convert analog signals into digital data without requiring a starting operation by a measuring person or a starting signal from an external device. It can be converted into a signal, and
It is an object of the present invention to provide an analog-to-digital conversion device capable of converting into a digital signal independent of the input/output characteristics of a detection device.

(Means for Solving the Problems) Therefore, in order to achieve the above object, the present invention is capable of converting an analog signal to a digital signal by activating the conversion device itself, and converting the converted digital signal. It is configured to convert into another digital signal with arbitrary characteristics that are not influenced by the characteristics of the analog input signal and output it.

(Example) The present invention will be explained below based on the illustrated example.
In the figure, 1 is an analog-to-digital converter;
This analog-to-digital converter 1 is configured as follows. Reference numeral 2 denotes an input holding means for inputting an analog signal AI and holding the analog signal AI until the conversion of the current analog signal A1 is completed by an input conversion means 3, which will be described later. Reference numeral 3 denotes input conversion means for converting the analog signal A2 output from the input holding means 2 into a digital signal. 4 holds the digital signal D1 converted by the input converting means 3, and converts the digital signal into another digital signal whose characteristics are not influenced by the characteristics of the analog input signal A1, It is a data conversion means that outputs. This data conversion means 4 uses a conversion table method using a microcomputer etc.
It involves data conversion, and if the conversion output value is monovalent with respect to the input value, conversion characteristics with arbitrary characteristics and arbitrary precision can be obtained as shown in FIG. As shown in FIG. 3, the conversion program executed by the above-mentioned micro combinator, etc. takes in the digital input, calculates the address (M=D+m) corresponding to the digital input, and stores it in the memory. The content of the memory corresponding to the address M is extracted from the converted table and output to the outside. As shown in the table below, the summer exchange table stored on the memory has a conversion output stored in a memory address corresponding to digital input, and this conversion output corresponds to the analog input signal A. It consists of a digital signal with arbitrary characteristics that are not influenced by characteristics.

Further, reference numeral 5 denotes an automatic start signal generation means for generating an automatic start signal E at the same time as the start of operation of the analog-to-digital converter 1. The reset signal generated at the same time as the switch turns on is called the automatic start signal E.

6 outputs a self-starting signal F to the input converting means 3 by the automatic starting signal E generated from the automatic starting signal generating means 5, and thereafter self-starting by the conversion completion signal G output from the input converting means 3. This is a self-starting signal generating means that outputs the signal F to the input converting means 3. 7 is the N+1st conversion completion signal G output from the input conversion means 3
The converted data holding means outputs the hold release signal K to the data converting means 4, resets the N-th digital signal held in the data converting means 4, and holds the N+1-th converted data.

(Function) Next, in the analog-to-digital converter configured as described above, a case will be described in which the analog signal A1 output from the position detecting device 8 is converted into a digital signal Dt.However, the position detecting device 8 is As shown in FIG. 4, it is assumed that the detected quantity has a non-linear input/output characteristic with respect to the position.In addition, here, the analog signal A1 is assumed to have a linear characteristic. The case of converting to a digital signal will be explained.

First, when the power of this analog/digital device 1 is turned on, at the same time, the automatic starting signal E is outputted from the automatic starting signal generating means 5, and the self starting signal generating means 6 is activated, and this self starting signal is generated. The input conversion means 3 is activated by the self-activation signal F outputted from the means 6. Therefore, the first analog signal A input from the position detecting device 8 to the analog-to-digital converter fil is held in the input holding means 2 and is sent to the input converting means 3 via the input holding means 2. Output. The analog signal A input to the input conversion means 3 is converted into a digital signal by the input conversion means 3. At this time, since the input conversion means 3 linearly converts the analog signal Alt into the digital signal D1, the analog signal A output from the position detection device 8 having non-linear input/output characteristics
1 is a digital signal D that has non-linear characteristics as it is.
It is converted to I. When the above conversion is completed, the digital signal D1 outputted from the input conversion means 3 is input to the data conversion means 4, and the conversion completion signal G is outputted from the human power conversion means 3. The data conversion means 4 holds the input digital signal D1 and converts the digital signal D1 into a digital signal having arbitrary characteristics that are not influenced by the characteristics of the analog signal AI output from the position detection device 8. Convert and output. That is, the characteristics of the analog signal A are non-linear, whereas the characteristics of the digital signal A are linear. The data conversion means 4 converts the detected amount to be detected by the position detection device 8 into
In order to convert it into a digital signal that accurately (linearly) corresponds to the detected quantity, one position detection device I! is used as shown in FIG. It has a conversion characteristic that is inversely related to the input/output characteristic of t8 (Fig. 4).

Therefore, from this data conversion means 4, the position detection device 8
A digital signal that accurately corresponds to the amount to be detected is output.

On the other hand, the input holding means 2 is reset by the conversion completion signal G output from the input converting means 3, and the second analog signal A inputted from the first position detection device 8 is held in the input holding means 2. , is output to the input conversion means 3 via the input holding means 2. Further, the self-starting signal generating means 6 is operated by the conversion completion signal G, and the self-starting signal F is outputted from the self-starting signal generating means 6.
K, the input conversion means 3 is activated for the second time.
The analog input to this input conversion means 3 (if No. At
is converted into a digital signal D1 by the doujinshi conversion means 3. Further, the converted data holding means 7 is activated by the first conversion completion signal G output from the input converting means 3 and outputs a holding release signal K to the data converting means 4, so that the data held in the data converting means 4 is Reset the previous data and retain the current data.

Similarly, when the conversion is completed by the input conversion means 3, the conversion by the analog-to-digital conversion device 1 is continued by the conversion completion signal GK sequentially outputted from the input conversion means 3.

Note that in the illustrated embodiment, the analog signal A1 to be converted is
Although the case has been described in which the position detection device 8 is used as the device for outputting , the present invention is not limited to this, and various detection devices such as a temperature detection device, a humidity detection device, a pressure detection device, etc. can be used. Of course.

Furthermore, in the above explanation, a case has been described in which an analog signal having non-linear input characteristics is converted into a digital signal having linear characteristics. For example, if an analog signal with non-linear input characteristics as shown in FIG.
It is clear that an analog input signal can be converted into a digital signal with arbitrary characteristics, such as converting into a digital signal with step-like characteristics as shown in FIG.

(Effects of the Invention) Since the present invention has the above-described configuration and operation, it does not require an external startup operation or a startup signal, so startup by the measurer or other equipment can be omitted, resulting in labor savings and cost reductions. can be realized, and automatic measurements can be performed using various detection devices.

In addition, instead of simply converting an analog signal into a digital signal and outputting it, the analog signal is converted into a digital signal, and this digital signal is then converted into a digital signal with arbitrary characteristics that are not influenced by the characteristics of the analog signal. Since I converted it to another digital signal and output it,
The analog signal output from the detection device can be converted into a digital signal that is not dependent on the input/output characteristics of the device, and the quantity to be detected by the detection device can be converted into a digital signal that accurately corresponds to the quantity. Furthermore, by replacing the data conversion means, the analog signal output from the detection device having arbitrary input/output characteristics can be converted into
It can be converted into a digital signal with arbitrary characteristics.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an analog-to-digital conversion device according to the present invention, FIG. 2 is a graph showing conversion characteristics of data conversion means, which is a component of the device, and FIG. 3 is a flowchart showing the conversion program used in the data conversion means, FIG. 4 is a graph showing input/output characteristics in the detection device, FIG. 5 is a graph showing conversion characteristics in the data conversion means, and FIG. 6 is a graph showing the conversion characteristics in the data conversion means. Graphs showing other embodiments of conversion characteristics, FIG. 7 is a block diagram showing a conventional analog-to-digital converter, and FIG. 8 is a graph showing input/output characteristics of a detection device. Explanation of symbols 3...Input conversion means 4...Data conversion means 5...Auto start signal generation means 6...Self start signal generation means A,, A2...Analog signal D,...
D...Digital signal E...Auto start signal
F... Self-starting signal G... Conversion completion signal Patent applicant: Japan Oil Seal Industries Co., Ltd. Figure 1 B I)
rFigure 2Figure 3Figure 4

Claims (1)

[Claims] An input conversion means for converting an input analog signal into a digital signal, and a digital signal converted by the input conversion means having arbitrary characteristics that are not influenced by the characteristics of the analog signal input to the input conversion means. data converting means for converting into a digital signal; automatic starting signal generating means for generating an automatic starting signal at the same time as the conversion device starts operating; a self-starting signal generating means for outputting a self-starting signal to the input converting means in response to a conversion completion signal outputted from the input converting means; An analog-to-digital conversion device characterized by sequentially activating.