JPS63131071A - Reactance value detector - Google Patents

Abstract

PURPOSE:To enable detection of a correct reactance value, by setting a reactance value so as to be proportional to a phase difference of a bridge phase difference generator. CONSTITUTION:A reactance value detector is provided with a bridge difference generator 2. Here, when a reactance value of a reactance element 7 is represented by X, a resistance value of a resistance 8 R, a voltage of a sine wave oscillator 1 Ein, an output of division of the voltage Ein by the resistance 8 and the resistance 8 Er and an output of division of the voltage Ein by the element 7 and the resistance 8 E0, Ein=2Emsinomegat (wherein Em is mesial magnitude and omega angular frequency) is given. The output Er and E0 are obtained by Er= Emsinomegat and E0=Emsin(omegat-phi) with phi as phase difference. Moreover, when the requirement of X<R is mset, E0=Emsin(omegat-2X/R) is given and as the phase difference phi is proportional to the reactance value, the reactance value can be detected easily if the phase difference between the outputs Er and E0 is found.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to inductance values, capacitance values, and reactance values as functions of their frequencies (hereinafter collectively referred to as these) in electronic equipment such as office equipment, measuring equipment, and communication equipment. This invention relates to a reactance value detection device that detects a reactance value (referred to as a reactance value).

Background of the Invention In recent years, sensor technology has made remarkable progress, and the importance of detection methods and electrical processing continues to grow.

Traditionally, reactance values have been detected by measuring analog levels of converted voltages or currents.

An example of the conventional reactance value detection device mentioned above will be described below with reference to the drawings. FIG. 4 shows a block circuit diagram of a conventional reactance value detection device, in which 10 is a sine wave oscillator, 11 is a reactance element such as a reactance element to be measured or a sensor whose output has reactance characteristics, 12 is an amplifier, and 13 is a rectifier, 14
15 is a DC amplifier, 15 is a level converter, 16 is a human/D converter, and 17 is a microprocessor.

The operation of the reactance value detection device configured as above will be described below.

First, the voltage across the reactance element 11, which increases in proportion to the reactance value, is amplified by the amplifier 12 to an appropriate amplitude, and then rectified by the rectifier 13 and converted into a DC signal.

Next, a DC amplifier 14 performs DC amplification, and a level converter 16 performs power level conversion, matching, etc. At this stage the signal is still an analog signal. Therefore, the microprocessor 17 can only accept this digital signal after it is A/D converted into a digital signal by the human/D converter 16.

Problems to be Solved by the Invention However, in the above configuration, information regarding the reactance value is included in the amplitude of the analog signal replaced by voltage or current, so the stability of the power supply is important, and the microprocessor etc. In order to perform digital processing using , it is necessary to convert the signal into a digital signal using the above-mentioned MU/D converter, resulting in a complicated configuration. Additionally, there is a problem in that quantization errors must be taken into account. Furthermore, multiplex detection, in which multiple reactance elements are used to switch and measure each time slot, is easily affected by offset and drift, so multiple circuit configurations are required before inputting to the MU/D converter. However, there are also problems in that the structure is complicated and the device becomes large.

In view of the above problems, the present invention does not include reactance value information in the amplitude of an analog signal, but instead includes reactance value information in the phase of a pulse signal, detects the phase difference with a reference signal, and detects the phase difference between the pulse signal and the reference signal. The present invention provides a reactance value detecting device that detects a reactance value by counting the reactance value.

Means for Solving the Problems In order to solve the above problems, the reactance value detection device of the present invention consists of a sine wave oscillator, a reactance element on one side, and a resistor of the same value on three sides. A bridge phase difference generator outputs a signal obtained by dividing the output of a sine wave oscillator between resistors, and a signal obtained by dividing the output of a reactance element and a resistor, and detects the phase difference between the outputs of this bridge phase difference generator. the reactance value of the reactance element is x,
When the resistance is R, the pulse width of the phase comparator output is made proportional to the reactance value so as to satisfy the condition of X<R, and the pulse width is counted by the judgment processing means to detect the reactance value. It is equipped with such a configuration.

Effect of the Invention The present invention uses the above-described configuration to set the level of the reactance value to be proportional to the phase difference of the bridge phase difference generator, so by detecting this phase difference, the square wave pulse corresponding to the value is determined. It can be detected as a pulse signal, which facilitates processing by a microprocessor, and also enables simple and accurate detection of reactance values.

Embodiment Hereinafter, a reactance value detection device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block circuit diagram of a reactance value detection device according to an embodiment of the present invention. In the figure, 1 is a sine wave oscillator consisting of a blocking oscillator, an OR oscillator, etc., 2 is a bridge phase difference generator, and 3 is an emitter follower. , a high input impedance circuit consisting of a cathode follower, a voltage follower, etc.; 4 a waveform shaper for amplitude manipulation and waveform shaping;
5 is a phase comparator which detects the phase difference between the two outputs from the waveform shaper 4 and outputs a time pulse including reactance value information; 6 is a microprocessor as a judgment processing means. As shown in FIG. 2, the bridge phase difference generator 2 has a reactance element 7 such as a reactance element to be measured or a sensor whose output has reactance characteristics on the - side, and resistors 8 of the same value on the other three sides. ing.

In the above configuration, now the reactance value of the reactance element 7 is x, the resistance value of the resistor 8 is R1, the voltage of the sine wave oscillator 1 is Kin, and the voltage between the resistors 8 and 8 is Kin.
The output obtained by dividing the voltage Kin is set as Er, the output obtained by dividing the voltage Kin by the reactance element 7 and the resistor 8 is set as EO, and the polarity of the reactance element 7 is set as an inductive element (impedance +j
X) is used, Ein:2 Kz Sinωt
−(1) (where Em is the half value of the sine wave amplitude and ω is its angular frequency) Then, the outputs Er and EO obtained by dividing the voltage Ein are as follows, where ψ is the phase difference, Er= Emsinωt −(
2) Ko = In (Em 6j ””−ψゝゝ〕=
= Emsin (ω is one ψ) ・−(
3) (However, m indicates the imaginary part.) However, if the condition of X<R is satisfied, ψ=2((x-)-i(5)3+cx-)5...)=
2 (Tao...Excess R3R6RR is obtained.At this time, the output Eo is Eo=Emsin (ωt-200)...
・(6), and the phase difference ψ is proportional to the reactance value X, so the output Er obtained by dividing the voltage Ein between the resistors
If the phase difference between the output obtained by dividing the voltage Kin and the reactance element and the resistor and EO is known, the reactance value can be easily detected.

On the other hand, as the polarity of the reactance element 7, a capacitive element (
When the impedance - j
...(i-), so that only the retardation of the phase difference changes with respect to the polarity of the reactance element 7. That is, whether the reactance element is inductive or capacitive, the reactance value can be determined with the same configuration. Third
These waveforms are shown in the figure.

Based on the above configuration, within the range where the condition X<R is satisfied, the time width of the output of the phase comparator is proportional to the reactance value, so the reactance value can be easily measured by counting this time width with a microprocessor. be able to. Furthermore, if the reactance element is controlled so that the reactance value is constant, it can be used in a wide range of applications. For example, in a development method using a two-component developer in a copying machine, it is necessary to maintain a constant ratio of toner and carrier, and when using magnetic toner, a magnetic detection sensor is used to detect a reactance value that corresponds to the toner concentration. There is a way to detect
By applying the reactance value detection device of the present invention to detect excess or deficiency of toner and controlling the toner supply amount, a toner concentration control device can be realized. Note that the medium-high input impedance circuit 3 and the waveform shaper 4 of this embodiment may be used as necessary, and are not necessarily required for the configuration.

Effects of the Invention As detailed above, according to the present invention, the reactance value is set to be proportional to the phase difference of the bridge phase difference generator, so by detecting this phase difference, a pulse corresponding to the reactance value can be generated. It can be detected as a pulse signal of a rectangular wave pulse with a width.

As a result, the interface with the microprocessor becomes easy and accurate reactance values can be detected. Furthermore, whether the reactance element is inductive or capacitive, the reactance value can be detected with the same configuration. Furthermore, since reactance value information is included in the phase of the pulse signal, it is less susceptible to power fluctuations, offsets, drifts, and the like. Furthermore, by switching the reactance element for each time slot, it is suitable for multiplexed detection using time division processing. Furthermore, by comparing the reactance value with a reference time value stored in advance, it is possible to determine whether the reactance value is excessive or insufficient, so that many effects such as the ability to continue to control the reactance value can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram of a reactance value detection device according to an embodiment of the present invention, Fig. 2 is a main circuit diagram of a bridge phase difference generator, Fig. 3 is a waveform diagram of the same, and Fig. 4 is a conventional reactance value detection device. FIG. 2 is a block circuit diagram of a value detection device. 1... Sine wave oscillator, 2... Bridge phase difference oscillator, 3... High input impedance circuit, 4... Waveform shaper, 5... ... Phase comparator, 6 ... Microprocessor, 7 ...
・Reactance element, 8°°゛°゛°resistance. Name of agent: Patent attorney Toshio Nakao and one other person
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Claims (1)

[Claims] Consisting of a sine wave oscillator, a reactance element on one side, and a resistor of the same value on three sides, a signal obtained by dividing the output of the sine wave oscillator between the resistances, and a signal obtained by dividing the output of the sine wave oscillator between the resistors and the reactance element and the resistance. and a phase comparator that detects a phase difference between the outputs of the bridge phase difference generator, and a judgment processing means, the reactance value of the reactance element is x, the resistance is When R, the pulse width of the output of the phase comparator is made proportional to the reactance value so as to satisfy the condition of X<R, and the pulse width is counted by the judgment processing means to detect the reactance value. A reactance value detection device characterized in that: