JPS62503140A - Analog duty cycle converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Analog duty cycle converter string distortion separation The present invention generally converts an analog electrical signal into an electrical signal with a duty cycle modulated. The equipment to be converted, more specifically the duty support depending on the position of the movable machine elements. The present invention relates to a device that generates an electrical signal whose frequency is modulated.

Minister Ibarakyu In the past, digitally controlled electronics, both in terms of products and manufacturing methods, were primarily Its use was hampered by the lack of an analog-to-digital signal converter. typical In a typical control system, error-protected transmission and subsequent microcomputer dual purpose for use in computers or other digital control systems Digital signals that sense and represent various mechanical operations or motions for It is necessary to generate Sensing and conversion methods must be accurate and rapid. The converter must be simple and affordable relative to the rest of the control circuit. No.

In response to this demand, many analog-to-digital converters have been developed. these devices come in a variety of forms, some suited only to the particular use for which they were designed. other “General” transducers offer more flexibility in application, but are complex and expensive. are susceptible to damage in industrial environments and, undesirably, to noise signals. I am affected by it.

The present invention senses mechanical position and responds to a predetermined frequency with modulated duty cycle. Particularly suitable for generating digital signals.

The resulting digital signal is transferred to its destination via various circuit paths and then Measure the generated duty cycle or even average the modulated signal Or it can be deciphered by filtering. The modulated signal can also be e.g. input into a computer to perform the various calculations needed for a particular control system. It can also be used to carry out.

Another problem with conventional transducers is that the actual sensing element is Each must be designed for a specific use case or must be sensed. Since there are various mechanical movements that must be carried out, it is difficult to use a general sensing element. One example is that the efficiency of use decreases. In the present invention, the predetermined transfer A resistive sensing element with a dynamic area is used. of the area of the resistive element Select a predetermined portion and mechanical position into a duty cycle modulated output signal Associated circuitry is provided to fully utilize the selected portion during conversion. Ru. Therefore, a single common sensing element can be used without compromising the desired resolution. A wide range of mechanical movements can be sensed.

The present invention seeks to solve one or more of the problems set forth above.

Start and practice In one aspect of the invention, the duet is adjusted in response to the position of the movable mechanical element. A device that generates an electrical signal with a modulated cycle must be supplied with a predetermined power supply voltage. Power supply means are provided. The transducer means is sized according to the position of the movable mechanical element generates an analog signal. The reference means has first and second magnitudes at a predetermined frequency. A reference signal is generated that varies between two predetermined values. The difference between the first and second predetermined values is At least one of them is controllably established by the area selection means. The conversion means is an analog signal. input the analog signal and reference signal, compare the analog signal and the reference signal, and calculate the frequency of the reference signal. frequency according to the frequency and the respective magnitudes of the analog signal and reference signal. A duty cycle modulated signal with Occurs between.

In the present invention, the machine position is converted into a digital signal whose duty cycle is modulated. A low cost and simple device is provided to replace the In addition, we use Hana-sensing elements to sensing the mechanical movement of surroundings without compromising the resolution of the resulting digital signal. Can be done.

Sarasara heavy nest star escape In the accompanying drawings, reference is made for a better understanding of the invention: FIG. A configuration diagram of one embodiment of; 2 and 3 are schematic diagrams collectively constituting one embodiment of the invention shown in FIG. 1; and Figure 4 shows signal timing used to explain the schematic diagrams shown in Figures 2 and 3. figure.

The best form for illumination In FIG. 1, an apparatus embodying some of the principles of the invention is generally designated by the reference numeral 10. It is shown in The detailed description below describes the best currently known embodiment of the device 10. Needless to say, it is about Mr. However, for those skilled in the art As will become clear below, the device 10 can be accessed without departing from the scope of the appended claims. It is a species that can take on other forms.

This device 10 has a predetermined power a! Power supply means 12 for generating voltage are provided. power hand The stage 12 is provided with a preregulator 14, and the input terminal of the preregulator is connected to the positive battery. Voltage, e.g. battery in a vehicle or positive power tap on a machine tool It is connected to the.

The pre-regulator 14 also has a pre-adjusted output voltage, e.g. a positive DCIO voltage. An output terminal is also provided to provide a power supply. The power supply means 12 also includes a voltage regulator 16. provided, the input terminal of the voltage regulator 16 is connected to the preregulator output terminal, and the input terminal of the voltage regulator 16 is connected to the preregulator output terminal. provides a fully regulated voltage output, eg, plus 5 volts DC. power hand Stage 12 is further provided with a negative power supply voltage terminal, illustrated with a conventional ground symbol.

The transducer means 1B corresponded to the position of the movable mechanical element 11 indicated by the block. Generates an analog signal of magnitude. The reference means 20 generates a reference signal and The magnitude varies linearly between the first and second predetermined values at a predetermined frequency. suitable In the embodiment, the reference means 20 includes a constant current source 22, a constant current sink 24 and a waveform controller. The capacitor 26, the threshold circuit 28, the launch circuit 30, and the trigger circuit 32. configured. The constant current devices 22 and 24 together with the waveform capacitor 26 form a threshold circuit. 28, and the threshold circuit 28 is also connected to a latch circuit. Latch circuit 3 0 is connected to the trigger circuit 32, and the trigger circuit 32 is connected to the constant current sink 24. Ru. The region selection means 34 are connected to the reference means 20, in particular to the threshold circuit 28, controllably establishing at least one of the first and second predetermined values of the signal; Limiting the effective operating area of stage 18.

The device 10 is also provided with conversion means 36, which convert the analog signal and the reference input the analog signal, compare the analog signal with the reference signal, and calculate the frequency of the reference signal. Ducts that correspond to the corresponding frequency and the respective magnitudes of the analog signal and reference signal. generates a duty cycle modulated output signal having a factor of . strange The switching means 36 is provided with a comparator 38 and an exciter circuit 40. Two comparators 38 The input terminal of is connected to the transducer means 18 and the waveform capacitor 26 of the reference means 20. , the output terminals are read directly to the exciter circuit 40.

2 and 3 are schematic diagrams of the various elements shown in blocks in FIG. Ru. The power supply means 12 are of conventional design and have a positive preconditioned and regulated supply voltage. Both a terminal and a negative supply voltage terminal are provided. A good practice is to measure the power supply Stage 12 has a pre-conditioned supply voltage of plus DCIO volts and a pre-conditioned plus D It generates a power supply voltage of C5 volts.

The transducer means 18 is provided with a potentiometer 42, the potentiometer 42 a resistive element 43 connected between the positive and negative regulated power supply voltage terminals; 3 and a mechanical wiper element 44 slidably engaged with the wiper element 44. Resistance element 43 The position of the wiper element 44 relative to the movable machine to which the wiper is mechanically connected This corresponds to the position of the machine element 11. The mechanical element 11 and its connection are different from each other in the present invention. The wiper element 44 is not specific (it is shown only as a block in the figure). A capacitor is connected to suppress electrical noise. In embodiments of the invention, Potentiometers of the type described above are used to convert mechanical positions into analog electrical signals. I am using it. However, other suitable transducers may be used to suit the needs of a particular application. Can be substituted. For example piezoelectric sensors, Hall effect sensors or optical sensors. It will be clear to those skilled in the art that 4 can be used as desired. chosen Certain transducers are capable of producing analogous voltage signals corresponding to the mechanical elements being monitored. must be able to

The reference means 20 is not complex, but contains some basic electrical elements. fixed The current source 22 is connected to the transistor 4 through a current limiting resistor 48 and connected to the current source terminal. Consists of 6. Transformers respond to traditional diode-type biasing circuit configurations. The resistor 46 generates a constant current at its collector terminal, and the magnitude of the constant current is determined by the bias current impression. The constant current sink 24 determined by the adder circuit and the value of the current limiting resistor 48 is now It has a similar design to the constant current source 22 described above, and the current is passed through the current limiting resistor 52. It consists of a transistor 50 connected to a current sink terminal. to constant current sink 24 is provided with a trigger input terminal for controlling the “on” and “off” states of the transistor 50. Constant current sink 24 differs from constant current source 22 in that it is To “on” In response to being triggered, transistor 50 receives a constant current at its collector terminal and The magnitude of the current is determined by a separate diode bias current application configuration and current limiting resistor 52. It is determined. There is a difference in the values of the current limiting resistors 48 and 52, so the constant current The magnitude of the constant current drawn by current sink 24 is determined by the constant current generated by constant current source 22. It becomes twice the current.

The collector terminals of the constant current devices 22 and 24 are both connected to the waveform capacitor 26 and the threshold circuit. 28 first and second input terminals, respectively. threshold times Channel 28 is comprised of first and second threshold detectors 54,56, each detector receiving a waveform. A first input terminal connected to capacitor 26 is provided. First threshold detector The second input terminal of 54 is connected to a regulated positive 5 volt DC current voltage terminal. It will be done. The second threshold detector 56 is connected to the “area” output terminal of the w4 area selection means 34. has a second "region" input terminal. The area selection means 34 is a voltage divider, which The first and second resistors 58 and 60 are connected to the positive 5 volt DC regulated supply voltage terminal and the negative is connected between the power supply voltage terminal of the

The output terminal of the first threshold detector 54 is connected to the "reset" terminal of the launch circuit 30. has been done. The output terminal of the second threshold detector 56 is the "set" terminal of the latch circuit 30. connected to the terminal. The “set” terminal of launch circuit 3o is connected by a voltage divider network. Via to a predetermined voltage level between the regulated supply voltage of plus 5 volts DC and ground. I'm being chased. The output terminal of latch circuit 30 is connected to a positive voltage through a voltage divider network. Connected to the DC 5 volt regulated power supply voltage terminal and the trigger circuit 320 input terminal. There is.

The trigger circuit 32 is responsive to the output signal from the latch circuit 30 having a first magnitude. is biased “on” and has a second magnitude output from the latch circuit. The transistor 62 is configured to turn "off" in response to a signal. Trigger circuit 32 The output terminal of the constant current sink 24 is connected to the trigger input terminal of the constant current sink 24. The on/off state of the transistor 50 is controlled.

The conversion means 36 comprises a comparator 38, the first input terminal of which is a waveform converter. The second input terminal is connected to the wiper element of the potentiometer 42. 44. The output terminal of comparator 38 is connected to exciter circuit 40.

The exciter circuit 40 is an open collector transistor circuit, and has a digital signal output terminal. A child 64 is provided.

The circuit described above is one embodiment of the invention. Ratings and values of the various electrical elements mentioned above It will be appreciated by those skilled in the art that this is for illustration purposes only. The above circuit and The design and implementation may vary and electrical components of different configurations or ratings may be used. It will be clear to those skilled in the art that it can be used. such changes or Substitutions may be made without departing from the scope of the appended claims.

Industrial applicability I The operation of the device 10 will be described with reference to the schematic diagrams in FIGS. 2 and 3 and the timing diagram in FIG. This is described next. A schematic diagram is provided to help you refer to the representative waveforms shown in the timing diagrams. , the same test point codes as those attached to each waveform are used.

Reference means 20 generates a substantially linear voltage waveform at reference signal output terminal TP4. . The reference signal output terminal TP4 is connected to the waveform capacitor 26 and the constant current device output terminal. This is a common point with the common input terminal to the value circuit 28.

When power is first applied to device 10, waveform capacitor 26 is connected across DCO. volts, and the output terminal TP2 of the second threshold detector 56 is at a "low" level. . Correspondingly, the output terminal TP3 of the launch circuit 30 is at a "high" level, and the trigger The circuit 32 prevents the constant current sink 24 from turning on. waveform condenser The constant current source 22 generates a positive DC voltage at a speed determined by the magnitude of the current supplied by the constant current source 22. It starts charging towards the IO volt supply voltage.

When the voltage across the waveform capacitor 26 reaches the first time, as shown as time T1 in FIG. When the reference voltage present at the second input terminal of the threshold detector 54 is exceeded, the first threshold detector 54 is exceeded. The output terminal TPI of the output device 54 outputs a “low” level signal, and the latch 30 is “reset”. ”, in which case the reference voltage present at the second input terminal of the first threshold detector 54 is It is fixed at the plus DC 5 volt power supply voltage level. Accordingly, the latch 30 The output terminal TP3 outputs a “low” level signal, and the constant current sink 2 is supplied to the trigger circuit 32. Turn on 4. The voltage across the waveform capacitor 26 is applied to the current limiting resistor 52. Therefore, the discharge starts immediately from the constant current sink 24 at the established speed. constant current Since the link 24 conducts current twice as fast as the current supplied by the constant current source 22, Waveform capacitor 26 discharges at the same rate as it was previously charged. 1st threshold inspection The output device 54 again generates a "high" level signal in response to the discharge, and the waveform capacitor 2 6, the voltage across the second threshold detector 56 reaches the second threshold detector 56 as shown at time T2 in FIG. 2 input terminals below the threshold voltage established by the region selection means 34. The circuit is stable until

In the embodiments shown in FIGS. 2 and 3, the waveform of the reference signal output terminal TP4 shown in FIG. The threshold voltage for region selection is, for example, a positive DC5 volt regulated voltage voltage, as shown in It is set to 25% of the source.

Therefore, the voltage across the waveform capacitor 26 is set by the area selection means 34. When the voltage is discharged below the threshold voltage, the output terminal TP2 of the second threshold detector 56 goes to the "low" level. A bell signal is output to "set" the launch circuit 30. Depending on this, the latch times The output terminal TP3 of the circuit 30 outputs a “high” level signal, and the trigger circuit 32 is supplied with a constant voltage. When the current sink 24 is turned "off", the waveform capacitor 26 is again passed through the constant current source 22. The battery will begin charging and the cycle described above will begin again.

Therefore, while power is applied to the device 10, the reference means 20 is 1! followed by criteria A substantially triangular waveform signal is generated at the signal output terminal TP4. The generated waveform is The threshold value set by the selection means 34 and the adjusted power supply voltage of plus 5 volts DC. It varies almost linearly between The frequency of the generated reference signal is determined by the constant current device 22.2. The rate at which the waveform capacitor 26 charges/discharges through 4 is determined by the rate at which the waveform capacitor 26 charges/discharges.

Wiper element 44 of potentiometer 42 is connected to a second input terminal of comparator 38. It is. The value of the voltage output from the wiper element 44 of the potentiometer is DC5pole) 11 is between the rectified power supply voltage and DCO volts or ground. Y The specific voltage value output from the resistor element 44 is determined by the resistor element 43 of the potentiometer. determined by the instantaneous position of the wiper element 44 with respect to.

The wiper element 44 of the potentiometer 42 is located in the middle with respect to the resistor element 43. Assuming that 2.5 volts DC is applied to the second input of comparator 38 as shown in FIG. output to the power terminal. The comparator output terminal is connected to the waveform reference signal whose magnitude is D When the reference signal is below the reference signal, a “low” logic value signal is output to the driver circuit 40. It outputs a "high" logic value signal while the magnitude exceeds DC2.5 volts.

Instead, the driver circuit 40 inputs the logic signal from the comparator 38, and as shown in FIG. At TP5, a duty signal is connected to the digital signal output terminal 64 as shown by the solid line. outputs an output signal in which the cycle is modulated. Driver circuit 40 has a more flexible design It is an open collector circuit to enable is connected to the positive supply voltage source. As an example, in Fig. 4, output terminal 6 4 is connected to the positive DC5 volt regulated power supply voltage through a pull-up resistor. .

The wiper element 44 of the potentiometer 42 is connected to a positive current tA voltage on the resistor element 43. By moving the second input terminal of the comparator 38 to a position close to the A DC voltage, for example 3.75 volts DC, is input. In response to this, the comparator 38 The duration of the “low” logic value signal at the output terminal of the The duration of the issue will be shorter. Correspondingly, the driver circuit 40 The digital output signal output to the signal output terminal 64 is output at TP5 in FIG. The comparator 38 changes rapidly as shown by the line. Therefore, the wiper element 44, the position of potentiometer 42 relative to resistive element 43 ultimately determines the position of potentiometer 42 in device 10. The duty cycle of the signal output to the digital signal output terminal 64 is determined.

The frequency of the modulated digital output signal for this duty cycle is determined by the reference signal. is fixed at a predetermined value. Therefore, the wiper element 44 of the potentiometer 42 The output signal chain 51') is determined only by the position.

In the embodiment described above, only 75% of the potentiometer iJf is under control. It is used for. The part to be used is established by the area selection means 34. Determined by threshold voltage. In other words, in the above embodiment, DCl, A wiper element voltage of less than 25 volts is the duty cycle of the modulated output signal. It has no effect on the file. However, the working part of the potentiometer area The entire range of the waveform reference signal is utilized throughout. For this reason, the device 10 High resolution is maintained throughout the selected operating range of the chometer.

In a preferred embodiment, one of the threshold voltages is provided by a positive 5 volt DC supply voltage. The second threshold voltage is fixed, and the other threshold voltage is varied by the area selection means 34. It will be clear to those skilled in the art that region selection means can be incorporated into the device 10. cormorant. By using these two area selection means, the potentiometer operating area can be Anywhere within the entire operating range of the tensionometer can be selected and the device 10 It can also be adapted to different usages.

The device 100 is ratiometric, with various components providing a reference signal and a region selection signal. , the first threshold detector reference signal, and the output from the wiper element 44 of the potentiometer. Each of these components collectively generates a is connected to a regulated 5 volt DC power supply voltage, so fluctuations in ambient temperature can cause It is possible to almost prevent the utility cycle modulated signal output from fluctuating. Ru.

Other aspects, objects, advantages, and uses of the invention can be learned from the drawings, disclosure, and appended claims. It can be obtained by

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Claims (1)

[Claims] 1. modulating the duty cycle in response to the position of the movable mechanical element (11); In a device (10) for generating an electric signal, the device includes: power supply means (12) for generating a predetermined power supply voltage; and the movable mechanical element (11). transducer means (18) for generating an analog signal with a magnitude dependent on the position of the transducer means (18); Generates a reference signal whose magnitude varies linearly between the first and second predetermined values at a predetermined frequency. reference means (20) for generating a reference signal; and at least one of the first and second values of said reference signal. and defines an effective operating area of the conversion reference signal means (18). area selecting means (34) for receiving the analog signal and the reference signal; The analog signal is compared with the reference signal, and the analog signal corresponds to a predetermined frequency of the reference signal. A data signal corresponding to the frequency and the respective magnitudes of the analog signal and the reference signal. Each reference output signal has a duty cycle modulated with a duty factor. A device characterized in that it is provided with conversion means (36) that occurs during the cycle of the signal. Place. 2. The device (10) according to claim 1, wherein the reference means (20) current source means 22 for generating a constant current of a first predetermined magnitude; and a current source means 22 for generating a constant current of a first predetermined magnitude; and a current sink means (24) for generating a constant current of the second predetermined constant current. A device characterized in that the current magnitude is twice the first predetermined constant current magnitude. . 3. The device (10) according to claim 2, wherein the reference means (20) is capable of controlling the constant current sink means (24) in accordance with the magnitude of the reference signal. A device characterized in that it is provided with trigger means (32) for turning "on" and "off". 4. In the device (10) according to claim 3, the reference signal has a substantially linear shape. A device characterized by a triangular voltage waveform. 5. Apparatus (10) according to claim 1, wherein said transducer means (18) includes a resistive element (43) connected to the power source means (12) and the resistive element (43). a wiper element (44) slidably engaged with a potentiometer ( 42) is provided, and the wiper element (44) is connected to the resistance element (43). The position corresponds to the position of said movable mechanical element (11) and said reference signal means (2). 0) is connected to the power source means (12) and is connected to the first and second predetermined values of the reference signal. At least one of the areas is selected by the area selection means (34) to 1. A device characterized in that it is set to a certain degree. 6. The device (10) according to claim 5, wherein the first and second reference signals An apparatus characterized in that the other of the two values is approximately equal to the predetermined power supply voltage. 7. The duty cycle is modulated in response to the position of the movable mechanical element (11). In a device (10) for generating an electrical signal, the device (10) comprises: a regulated voltage source (16) with positive and negative supply voltage terminals, said positive and negative supply voltage; A resistive element (43) connected between the terminals is slidably engaged with the resistive element (43). a wiper element (44), the resistance of the wiper element (44) The position relative to the element (43) corresponds to the position of said movable mechanical element (11). a potentiometer (42), an area input terminal and a reference signal output terminal, a reference signal generator (20) connected between the positive and negative power supply voltage terminals; The positive and negative power supplies have a region output terminal connected to the region input terminal of the quasi-signal generator. a voltage divider (34) connected between the voltage terminals; a first input terminal connected to the reference signal output terminal; and a first input terminal connected to the reference signal output terminal; a comparator having a second input terminal connected to the wiper element (44) and an output terminal; (38), an input terminal connected to the output terminal of the comparator, and a digital signal output terminal. and a signal exciter (40) having a child (64) and a signal exciter (40). Place. 8. Apparatus (10) according to claim 7, in which the reference signal generator (2 0) is an output terminal connected to the reference signal output terminal and the positive power supply voltage terminal. a constant current source (22) having a current source terminal connected thereto; and a constant current source (22) connected to the reference signal output terminal. The output terminal connected to the a constant current sink (24) having a current sink terminal; a constant current sink (24) having a current sink terminal; a capacitor (26) connected between the power supply voltage terminal and the reference signal output terminal; a first input terminal connected to the positive power supply voltage terminal; and a second input terminal connected to the positive power supply voltage terminal. a first threshold detector (54) having a first detector output terminal and a first detector output terminal; a first input terminal connected to the area output terminal; and a second input terminal connected to the area output terminal. a second threshold detector (56) having an input terminal and a second detector output terminal; a “reset” terminal connected to the first detector output terminal; a “reset” terminal connected to the second detector output terminal; a latch circuit (30) having a "set" terminal and an output terminal connected; The input terminal connected to the switch output terminal and the constant current sink input terminal are connected to one terminal. A transistor (62) having an output terminal connected to the transistor (62). equipment.