CN211089621U - Digital processing circuit for output signal of coil type electromagnetic induction sensor - Google Patents
Digital processing circuit for output signal of coil type electromagnetic induction sensor Download PDFInfo
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- CN211089621U CN211089621U CN201922081123.3U CN201922081123U CN211089621U CN 211089621 U CN211089621 U CN 211089621U CN 201922081123 U CN201922081123 U CN 201922081123U CN 211089621 U CN211089621 U CN 211089621U
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Abstract
The utility model provides a digital processing circuit of coil type electromagnetic induction sensor output signal, is including setting up the induction magnet between sensor coil and the object to be measured, and the positive and negative two-pole input of comparator is connected at sensor coil's both ends, is equipped with RC filter circuit on the positive input circuit of comparator or the negative pole input circuit, and the positive input of comparator passes through circuit lug connection with the output of comparator to be provided with positive feedback resistance R2 on this connecting circuit. The utility model discloses sensor coil does not meet with ground GND, but links to each other with two inputs of comparator, and the reference voltage that positive input end or the negative pole input of comparator are connected is the fixed value, and reference voltage provides in addition, does not also near the power near 0V, keeps away from the interference in power and the ground wire. The utility model discloses whole circuit can realize through single power, and the interference is little, and the performance is good, simple structure, strong adaptability.
Description
Technical Field
The utility model relates to a signal processing circuit, concretely relates to coil type electromagnetic induction sensor output signal's digital processing circuit is applicable to the weak small signal conversion of sensor output for digital level signal if spinning frame spindle rotational speed detects.
Background
The electromagnetic induction sensor is widely applied to a spinning machine spindle rotating speed detection system in recent years due to the characteristics of high reliability and accurate measurement. However, in order to reduce the influence of the sensor on the spinning, the sensor is far away from the steel wire ring, so that the output signal of the sensor is very weak. The digital processing of weak and small signals is one of the main technologies of the spindle rotating speed detection system of the spinning frame. Because the output signal of the sensor is weak, the output signal is generally subjected to multistage amplification, filtering and digitization by a comparator, and a bipolar power supply is also needed, so that the circuit is complex and the cost is high. Another method is to use a comparator, as in patent CN201320378930.1, the voltage at two inputs of the comparator is relative to ground, the reference voltage can only set a threshold within the signal strength range to filter the interference, but the signal is very small, so the threshold voltage can only be very small, and the reference voltage cannot be far from 0V. In the two schemes, the sensor and the signal processing circuit are directly connected with the ground wire in the circuit principle, so that the ground wire interference is easily generated.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to the weak little of coil type electromagnetic induction sensor output signal among the above-mentioned prior art, can not reliably convert the problem into digital level signal, provide a coil type electromagnetic induction sensor output signal's digital processing circuit, whole circuit can realize promptly through single power, and the interference is little, and the performance is good, simple structure, strong adaptability.
In order to achieve the above object, the present invention provides the following technical solutions:
a digital processing circuit of coil type electromagnetic induction sensor output signal is characterized in that: the sensor comprises an induction magnet arranged between a sensor coil and an object to be detected, wherein two ends of the sensor coil are connected with positive and negative pole input ends of a comparator, an RC filter circuit is arranged on a positive pole input circuit or a negative pole input circuit of the comparator, the positive pole input end of the comparator is directly connected with the output end of the comparator through a circuit, and a positive feedback resistor R2 is arranged on the connection circuit; when the negative input end of the comparator loads the reference voltage Vref, the digital processing circuit forms a forward hysteresis comparator, and when the positive input end of the comparator loads the reference voltage Vref, the digital processing circuit forms a reverse hysteresis comparator.
The RC filter circuit comprises a filter resistor R1 and a filter capacitor C2, the filter resistor R1 is connected in series with the positive input circuit or the negative input circuit of the comparator, and the filter capacitor C2 is connected in parallel between the positive input circuit and the negative input circuit of the comparator; a filter capacitor C2 is connected in circuit behind the filter resistor R1, in the direction of the sensor coil to the comparator.
The filter resistor R1 contains the internal resistance of the sensor coil.
Connect the second grade filter circuit between the anodal input circuit of comparator and the negative pole input circuit, the second grade filter circuit is including the second grade filter resistance R3 and the second grade filter capacitance C1 of establishing ties together, the both ends of second grade filter circuit are connected respectively on positive pole input circuit and the negative pole input circuit of comparator between filter resistance R1 and filter capacitance C2.
A follower is arranged on a positive input circuit or a negative input circuit of the comparator;
the output end of the follower is connected to the positive input end of the comparator through a follower output filter circuit, and the follower output filter circuit comprises a follower output resistor R4 connected between the output end of the follower and the positive input end of the comparator and a follower output capacitor C3 connected between the follower output circuit and the negative input circuit of the comparator in parallel.
The positive input end of the follower is connected with the output end of the RC filter circuit, and a positive feedback resistor R2, a follower output resistor R4 and a follower output capacitor C3 have a common end which is connected to the positive input end of the comparator.
The follower output capacitor C3 is connected between the output end of the follower and the positive input end of the comparator, and the follower output resistor R4 is connected between the follower output circuit and the negative input circuit of the comparator in parallel.
The positive input end of the follower is connected with the output end of the RC filter circuit, and a positive feedback resistor R2, a follower output resistor R4 and a follower output capacitor C3 have a common end which is connected to the positive input end of the comparator.
The outputs of the sensor coils are connected with a digital processing circuit through the same multi-way selection switch.
The sensor coil is connected to the ground GND, but is connected to two inputs of a comparator, a reference voltage Vref connected to the positive or negative input of the comparator is a fixed value, the reference voltage is not provided near 0V, but near the power source, and the value is preferably selected from 1/5Vcc to 4/5Vcc, so that the output signal of the sensor coil is small, and the reference voltage is swung only near Vref, and is connected to the input of the comparator after being filtered by the RC filter circuit, and is used as an input signal, and is also kept away from the interference in the power source and the ground together with the filter circuit, under the action of the feedback resistor, the comparator becomes a special hysteresis comparator, the Vref at the base point is different from the application circuit of the conventional comparator, the whole processing circuit is not far away from the interference of the ground wire and the power source, and the reference voltage Vref of the sensor coil can be adjusted by the bias voltage of the resistor, so that the comparison between the reference voltage Vref and the ground wire voltage of the sensor coil can be adjusted by a high voltage, and the bias voltage of the sensor coil can be adjusted by a high voltage reference voltage, and the bias voltage of the resistor, and the bias voltage of the sensor coil can be adjusted by a high voltage.
Drawings
Fig. 1 is a schematic diagram of a basic circuit structure of a forward hysteresis comparator according to the present invention;
fig. 2 is a schematic diagram of a circuit structure of the forward hysteresis comparator with two-stage filtering;
FIG. 3 is a schematic diagram of a forward hysteresis comparator with enhanced circuit drive of a follower;
FIG. 4 is a schematic diagram of a forward hysteresis comparator with two stages of filter circuits and follower circuits;
FIG. 5 is a schematic diagram of a forward hysteresis comparator with a feedback resistor of a follower circuit;
FIG. 6 is a schematic diagram of the forward hysteresis comparator with two stages of filter circuits and a feedback resistor of the follower circuit;
FIG. 7 is a schematic diagram of a structure in which a plurality of sensor coils are connected to a comparator via a multi-way selector switch;
fig. 8 is a graph of the output characteristic of the circuit forming the hysteresis comparator of the present invention;
fig. 9 is a waveform conversion diagram of the digital processing of the output signal of the circuit sensor.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Referring to fig. 1, the utility model discloses a processing circuit is including setting up the induction magnet between sensor coil Snr and the await measuring object, and the positive and negative two poles of the earth input of comparator is connected at sensor coil Snr's both ends, is provided with RC filter circuit on the positive input circuit of comparator or the negative pole input circuit. The RC filter circuit comprises a filter resistor R1 and a filter capacitor C2, the filter resistor R1 is connected in series with the positive input circuit or the negative input circuit of the comparator, and the filter capacitor C2 is connected in parallel between the positive input circuit and the negative input circuit of the comparator; a filter capacitor C2 is connected in circuit behind the filter resistor R1 in the direction from the sensor coil to the comparator. The filter resistance R1 contains the internal resistance of the sensor coil. And a positive feedback resistor R2 is arranged between the positive electrode input end circuit of the comparator and the output end of the comparator. A reference voltage Vref may be connected to the negative input of the comparator, forming a positive hysteresis comparator; the reference voltage Vref may also be connected to the positive input of the comparator, forming an inverting hysteresis comparator.
Referring to fig. 2, such a secondary filter circuit may be connected between the positive input circuit and the negative input circuit of the comparator, the secondary filter circuit includes a secondary filter resistor R3 and a secondary filter capacitor C1 connected in series, and both ends of the secondary filter circuit are connected to the positive input circuit and the negative input circuit of the comparator between the filter resistor R1 and the filter capacitor C2.
Referring to fig. 3-4, on the basis of a basic circuit or two-stage filter circuit, a follower may be connected between the positive input circuit and the negative input circuit of the comparator, and the follower is followed by a follower output resistor R4 and a follower output capacitor C3 for filtering, and then connected to the positive input end of the comparator. A reference voltage Vref may be connected to the negative input of the comparator, forming a positive hysteresis comparator; a reference voltage Vref may also be connected to the positive input of the comparator, forming an inverting hysteresis comparator.
Referring to fig. 5-6, the positions of the follower output resistor R4 and the follower output capacitor C3 can be interchanged, the access position of the positive feedback resistor R2 can be moved backward, the positive input end of the follower is connected with the output end of the RC filter circuit, the positive feedback resistor R2, the follower output resistor R4 and the follower output capacitor C3 have a common end, and the common end is connected with the positive input end of the comparator.
Referring to fig. 7, the utility model discloses a processing circuit can connect digital processing circuit through same multiple selector switch when measuring a plurality of sensor coils, adopts the timesharing method can measure the average throughput rate of a plurality of objects in proper order. In this circuit, the comparator and all the functional circuits before it, including the multi-way selector switch and the sensor themselves, are far away from the interference of the ground wire of the power supply with the Vref, and the signal transmission process of the coil is relative to the reference voltage Vref, so that the multi-way measuring circuit is greatly simplified. The scheme is very suitable for measuring the rotating speed of the spindles of the spinning frame, and a group of spindles can share one signal conversion circuit.
Referring to fig. 8-9, the present invention provides an induction magnet between the sensor coil and the object to be measured, which causes the change of the magnetic field of the magnet when the object to be measured passes through near the magnet rapidly, thereby generating induced electromotive force in the sensor coil. Firstly, the utility model discloses a sensor coil does not meet with ground GND, but the coil both ends link to each other with the two input of comparator. One terminal is connected to the negative input of the comparator and is connected to a reference voltage Vref, which is a fixed value, not around 0V, not around the power supply, preferably chosen between 1/5Vcc and 4/5Vcc, in order to keep away from disturbances in the power supply and ground. The output signal of the other end of the sensor coil is very small, the sensor coil only swings near the reference voltage Vref, and the sensor coil is filtered by a filter resistor R1 and a filter capacitor C2 of an RC filter circuit and then directly connected with the positive input end of the comparator to be used as an input signal, and the input signal and the filter circuit are jointly far away from the interference in a power supply and a ground wire. Under the action of the positive feedback resistor R2, the comparator in the circuit of the present invention becomes a special hysteresis comparator, and the base point of the hysteresis is the reference voltage Vref. Unlike conventional comparator application circuits, the entire processing circuit is far from ground and power supply disturbances. Because of the effect of the positive feedback resistor R2, when no object passes through the magnet, no electromotive force is induced in the coil, and under the partial voltage of the resistors R1 and R2, the positive and negative ends of the comparator generate a bias voltage, so that the output of the comparator is kept at a high level or a low level. When the object to be measured passes through the magnet rapidly, the change and recovery of the magnetic field can be caused, so that the coil can generate a voltage signal similar to a sine wave period. This signal will swing on the basis of Vref and the comparator output will jump when the swing amplitude exceeds the bias voltage at the comparator input.
The present invention relates to a power source circuit for a portable electronic device, and more particularly to a power source circuit for a portable electronic device, which uses an induced voltage generated by a sensor coil as an input voltage Vin, wherein the input voltage Vin is relative to a reference voltage Vref, and is not relative to the ground, i.e., the voltage on both sides of the sensor coil, wherein the threshold voltage VH, V L also means the threshold voltage on both sides of the sensor coil, and is not relative to the ground, and when no signal is output, Vin is 0, and under the action of the positive feedback of a resistor R2, the comparator output is maintained at a high or low level, and when the comparator output is analyzed to be at a high level, the positive input voltage V + of the comparator is higher than Vref due to the voltage division of resistors R1 and R567, the comparator input voltage V + is lower than the reference voltage Vref, which is equal to the positive input voltage V L (VoutH-Vref-R1/R2), only the sensor output is lowered to Vref-Vin-L, the positive input voltage V + may break through the positive feedback of a positive feedback resistor R2, and the Vref-Vref, and the ground line voltage may be adjusted to a larger amplitude, and the ground line voltage of a high voltage, and a high voltage signal output, which the ground line voltage may be adjusted by a high voltage, and a high voltage may be adjusted by a high voltage.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical solution, it should be understood by those skilled in the art that the technical solution can also be modified and replaced by a plurality of simple modifications and replacements without departing from the spirit and principle of the present invention, and these modifications and replacements also fall into the protection scope of the claims.
Claims (9)
1. A digital processing circuit of coil type electromagnetic induction sensor output signal is characterized in that: the sensor comprises an induction magnet arranged between a sensor coil and an object to be detected, wherein two ends of the sensor coil are connected with positive and negative pole input ends of a comparator, an RC filter circuit is arranged on a positive pole input circuit or a negative pole input circuit of the comparator, the positive pole input end of the comparator is directly connected with the output end of the comparator through a circuit, and a positive feedback resistor R2 is arranged on the connection circuit; when the negative input end of the comparator loads the reference voltage Vref, the digital processing circuit forms a forward hysteresis comparator, and when the positive input end of the comparator loads the reference voltage Vref, the digital processing circuit forms a reverse hysteresis comparator.
2. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 1, wherein: the RC filter circuit comprises a filter resistor R1 and a filter capacitor C2, the filter resistor R1 is connected in series with the positive input circuit or the negative input circuit of the comparator, and the filter capacitor C2 is connected in parallel between the positive input circuit and the negative input circuit of the comparator; a filter capacitor C2 is connected in circuit behind the filter resistor R1, in the direction of the sensor coil to the comparator.
3. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 2, wherein: the filter resistor R1 contains the internal resistance of the sensor coil.
4. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 2, wherein: connect the second grade filter circuit between the anodal input circuit of comparator and the negative pole input circuit, the second grade filter circuit is including the second grade filter resistance R3 and the second grade filter capacitance C1 of establishing ties together, the both ends of second grade filter circuit are connected respectively on positive pole input circuit and the negative pole input circuit of comparator between filter resistance R1 and filter capacitance C2.
5. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 2 or 4, wherein: a follower is arranged on a positive input circuit or a negative input circuit of the comparator;
the output end of the follower is connected to the positive input end of the comparator through a follower output filter circuit, and the follower output filter circuit comprises a follower output resistor R4 connected between the output end of the follower and the positive input end of the comparator and a follower output capacitor C3 connected between the follower output circuit and the negative input circuit of the comparator in parallel.
6. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 5, wherein: the positive input end of the follower is connected with the output end of the RC filter circuit, and a positive feedback resistor R2, a follower output resistor R4 and a follower output capacitor C3 have a common end which is connected to the positive input end of the comparator.
7. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 5, wherein: the follower output capacitor C3 is connected between the output end of the follower and the positive input end of the comparator, and the follower output resistor R4 is connected between the follower output circuit and the negative input circuit of the comparator in parallel.
8. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 7, wherein: the positive input end of the follower is connected with the output end of the RC filter circuit, and a positive feedback resistor R2, a follower output resistor R4 and a follower output capacitor C3 have a common end which is connected to the positive input end of the comparator.
9. The circuit for digitizing an output signal of a coil-type electromagnetic induction sensor according to claim 1, wherein: the outputs of the sensor coils are connected with a digital processing circuit through the same multi-way selection switch.
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CN113556107A (en) * | 2021-07-28 | 2021-10-26 | 东莞铭普光磁股份有限公司 | Hysteresis-adjustable comparator circuit, digital oscillator circuit and electronic device |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CN113556107A (en) * | 2021-07-28 | 2021-10-26 | 东莞铭普光磁股份有限公司 | Hysteresis-adjustable comparator circuit, digital oscillator circuit and electronic device |
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