CN219496518U - Zero-crossing detection circuit and device - Google Patents
Zero-crossing detection circuit and device Download PDFInfo
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- CN219496518U CN219496518U CN202223353991.0U CN202223353991U CN219496518U CN 219496518 U CN219496518 U CN 219496518U CN 202223353991 U CN202223353991 U CN 202223353991U CN 219496518 U CN219496518 U CN 219496518U
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Abstract
The utility model discloses a zero-crossing detection circuit and a device, wherein the circuit comprises: the signal generating unit is used for generating zero crossing signals according to the voltages of the to-be-measured line pairs, the input end of the signal generating unit is connected with the first to-be-measured line of the to-be-measured line pairs, and the output end of the signal generating unit is connected with the zero crossing signal receiving circuit so as to output zero crossing signals to the zero crossing signal receiving circuit; the clamping unit is used for clamping the upper limit and the lower limit of the voltage of the zero-crossing signal and is connected with the output end of the signal generating unit and a second to-be-detected line in the to-be-detected line pair; the pull-up unit is used for pulling up the output end of the signal generation unit and is connected with the output end of the signal generation unit; the utility model has the advantages of simple circuit structure, low cost, low power consumption, high reliability and the like, and can also prevent the zero-crossing signal receiving circuit from being damaged due to the overcurrent or overvoltage of the zero-crossing signal.
Description
Technical Field
The utility model relates to the technical field of zero-crossing detection, in particular to a zero-crossing detection circuit and a zero-crossing detection device.
Background
In the prior art, the zero-crossing detection circuits are of various types, but most of the zero-crossing detection circuits have the defects of complex circuit structure, high cost, high power consumption and the like.
Disclosure of Invention
The utility model aims to provide a zero-crossing detection circuit and a zero-crossing detection device.
The technical scheme adopted for solving the technical problems is as follows: a zero-crossing detection circuit is constructed, comprising:
the signal generation unit is used for generating a zero crossing signal according to the voltage of the to-be-tested line pair, the input end of the signal generation unit is connected with the first to-be-tested line of the to-be-tested line pair, and the output end of the signal generation unit is connected with the zero crossing signal receiving circuit so as to output the zero crossing signal to the zero crossing signal receiving circuit;
the clamping unit is used for clamping the upper limit and the lower limit of the voltage of the zero crossing signal and is connected with the output end of the signal generating unit and a second to-be-detected line in the to-be-detected line pair;
and the pull-up unit is used for pulling up the output end of the signal generation unit and is connected with the output end of the signal generation unit.
Preferably, the signal generating unit includes a first resistor and a second resistor; the first end of the first resistor is used as the input end of the signal generating unit, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is used as the output end of the signal generating unit.
Preferably, the pull-up unit includes a third resistor; the output end of the signal generating unit is connected to a direct current voltage through the third resistor.
Preferably, the zero-crossing detection circuit further comprises a current limiting unit; the output end of the signal generating unit is connected with the input end of the current limiting unit, and the output end of the current limiting unit is connected with the zero crossing signal receiving circuit.
Preferably, the current limiting unit includes a fourth resistor; the output end of the signal generating unit is connected to the zero crossing signal receiving circuit through the fourth resistor.
Preferably, the zero-crossing detection circuit further comprises a filtering unit; the output end of the current limiting unit is connected to the ground through the filtering unit.
Preferably, the filtering unit includes a first capacitor; the output end of the current limiting unit is connected to the ground through the first capacitor.
Preferably, the clamping unit includes a first diode and a second diode; the anode of the first diode and the cathode of the second diode are connected with the output end of the signal generating unit, the cathode of the first diode is connected with direct-current voltage, and the anode of the second diode is connected with the second to-be-tested line and ground.
Preferably, the clamping unit includes a zener diode; and the anode of the voltage stabilizing diode is connected with the second to-be-tested line and the ground, and the cathode of the voltage stabilizing diode is connected with the output end of the signal generating unit.
The utility model also constructs a zero-crossing detection device which comprises the zero-crossing detection circuit provided by the embodiment of the utility model.
The utility model has the following beneficial effects: by a zero crossing detection circuit, comprising: the device comprises a signal generating unit for generating a zero crossing signal according to the voltage of a to-be-tested pair, a clamping unit for clamping the upper limit and the lower limit of the voltage of the zero crossing signal, and a pull-up unit for pulling up the output end of the signal generating unit; the utility model has the advantages of simple circuit structure, low cost, low power consumption, high reliability and the like, and can also prevent the zero-crossing signal receiving circuit from being damaged due to the overcurrent or overvoltage of the zero-crossing signal.
Drawings
The utility model will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic diagram of a zero crossing detection circuit provided by the present utility model;
FIG. 2 is a circuit diagram of an embodiment of a zero crossing detection circuit provided by the present utility model;
fig. 3 is a circuit diagram of a zero-crossing detection circuit according to an embodiment of the present utility model.
Detailed Description
For a clearer understanding of technical features, objects and effects of the present utility model, a detailed description of embodiments of the present utility model will be made with reference to the accompanying drawings.
The present utility model provides a zero-crossing detection circuit with reference to fig. 1, comprising: a signal generating unit 1 for generating a zero crossing signal according to the voltage of the pair to be tested, a clamping unit 2 for clamping the upper and lower voltage limits of the zero crossing signal, and a pull-up unit 3 for pulling up the output end of the signal generating unit 1.
The input end of the signal generating unit 1 is connected with a first to-be-measured line in the to-be-measured line pair, and the output end of the signal generating unit 1 is connected with a zero-crossing signal receiving circuit so as to output a zero-crossing signal to the zero-crossing signal receiving circuit; the clamping unit 2 is connected with the output end of the signal generating unit 1 and a second to-be-tested line in the to-be-tested line pair; the pull-up unit 3 is connected to the output of the signal generating unit 1.
In this embodiment, the to-be-detected line refers to a pair combination of ac conduction, and may also be a combination of any two phase lines in the three-phase power, or a combination of a phase line and a ground line.
In some embodiments, the signal generating unit 1 comprises at least two voltage dividing resistors; each voltage dividing resistor is connected in series to form a series chain; one end of the serial chain is an input end of the signal generating unit 1, and the other end is an output end of the signal generating unit 1. It can be appreciated that the provision of a plurality of voltage dividing resistors is beneficial to adjusting the total resistance value of the series chain, providing the debugging flexibility of the zero-crossing detection circuit.
In some embodiments, as shown in fig. 2 or 3, the signal generating unit 1 includes a first resistor R1 and a second resistor R2; the first end of the first resistor R1 is used as the input end of the signal generating unit 1, the second end of the first resistor R1 is connected with the first end of the second resistor R2, and the second end of the second resistor R2 is used as the output end of the signal generating unit 1.
In some embodiments, as shown in fig. 2 or 3, the pull-up unit 3 includes a third resistor R3; the output of the signal generating unit 1 is connected to a dc voltage via a third resistor R3. The voltage of the output end of the signal generating unit 1 may be uncertain due to abnormal conditions such as poor contact or power failure of the to-be-tested line pair, and the third resistor R3 is a pull-up resistor, so that the voltage of the output end of the signal generating unit 1 can be fixed to be high level, and further the zero crossing signal receiving circuit is prevented from mismeasuring the zero crossing signal.
In order to avoid damage caused by overcurrent after the zero-crossing signal receiving circuit receives the zero-crossing signal, in some embodiments, as shown in fig. 2 or fig. 3, the zero-crossing detection circuit further includes a current limiting unit 4 for limiting the current of the zero-crossing signal; the output end of the signal generating unit 1 is connected with the input end of the current limiting unit 4, and the output end of the current limiting unit 4 is connected with a zero crossing signal receiving circuit.
Further, as shown in fig. 2 or fig. 3, the current limiting unit 4 includes a fourth resistor R4; the output terminal of the signal generating unit 1 is connected to a zero crossing signal receiving circuit via a fourth resistor R4.
In order to improve the stability, reliability and anti-interference performance of the zero-crossing signal, in some embodiments, as shown in fig. 2 or fig. 3, the zero-crossing detection circuit further includes a filtering unit 5 for filtering the zero-crossing signal; the output of the current limiting unit 4 is connected to ground via a filtering unit 5.
Further, as shown in fig. 2 or fig. 3, the filtering unit 5 includes a first capacitor C1; the output of the current limiting unit 4 is connected to ground via a first capacitor C1.
In some embodiments, as shown in fig. 2, the clamping unit 2 includes a first diode D1 and a second diode D2; the anode of the first diode D1 and the cathode of the second diode D2 are connected with the output end of the signal generating unit 1, the cathode of the first diode D1 is connected with direct-current voltage, and the anode of the second diode D2 is connected with the second to-be-tested line and ground.
In some embodiments, as shown in fig. 3, the clamping unit 2 includes a zener diode D3; the anode of the zener diode D3 is connected to the second to-be-tested line and ground, and the cathode of the zener diode D3 is connected to the output end of the signal generating unit 1.
It should be noted that, the difference between the first embodiment shown in fig. 2 and the second embodiment shown in fig. 3 is that the clamping unit 2 has different compositions, but the functions are the same, and the clamping unit is used for clamping the upper limit voltage value of the zero-crossing signal to a certain set value when the sine wave input by the wire pair to be detected is in the positive half cycle (the positive half axle is the half cycle of the phase line L voltage being greater than the phase line N), and clamping the lower limit voltage value of the zero-crossing signal to another set value when the sine wave input by the wire pair to be detected is in the negative half cycle (the positive half axle is the half cycle of the phase line L voltage being less than the phase line N), so as to avoid the damage caused by overvoltage after the zero-crossing signal receiving circuit receives the zero-crossing signal; in addition, the zero-crossing signal receiving circuit refers to a control circuit or a controller which needs to acquire a zero-crossing signal, such as a control circuit or a controller of equipment such as a refrigerator, an electric vehicle and the like.
In some embodiments, the zero crossing detection circuit further comprises a voltage conversion circuit for providing a direct voltage. The voltage conversion circuit may be a switching power supply circuit commonly used in the prior art.
Referring to fig. 1, the zero-crossing detection circuit according to the first embodiment operates as follows:
a1, when a sine wave input by a line pair to be detected is in a positive half cycle, the conducting current of a zero crossing detection circuit sequentially passes through a first line to be detected (phase line L), a first resistor R1, a second resistor R2, a fourth resistor R4, a zero crossing signal receiving circuit, a grounding end and a second line to be detected (phase line N), and at the moment, the zero crossing signal (voltage of the second end of the second resistor R2) is relatively positive voltage to the ground, the positive voltage changes along with the positive half-wave change of the sine wave, the positive voltage is in a trend of increasing first and then reducing, but under the action of a first diode D1, the zero crossing signal is clamped to be the sum of the direct current voltage and the forward conducting voltage of the first diode D1, but when the positive half wave is just increased and is reduced to be close to 0V, the clamping action of the first diode D1 is invalid, and at the moment, the zero crossing signal receiving circuit detects that the zero crossing signal is close to 0V, and therefore the zero crossing signal receiving circuit detects two low levels with shorter duration in the positive half cycle;
a2, when the sine wave input by the line pair to be tested is in a negative half cycle, under the forward conduction action of the second diode D2, the positive conduction voltage of the second diode D2 is clamped between a port for receiving a zero-crossing signal in the zero-crossing signal receiving circuit and the ground, and is negative relative to the ground, so that in the negative half cycle, the zero-crossing signal receiving circuit can detect continuous negative voltage, namely low level; it will be appreciated that, in accordance with this law, the zero-crossing signal receiving circuit may determine the zero-crossing time by analyzing the detected change in the zero-crossing signal.
Referring to fig. 2, the zero-crossing detection circuit according to the second embodiment operates as follows:
b1, when sine waves input by a wire pair to be detected are in a positive half cycle, conducting current of a zero-crossing detection circuit sequentially passes through a first wire to be detected (phase line L), a first resistor R1, a second resistor R2, a fourth resistor R4, a zero-crossing signal receiving circuit, a grounding end and a second wire to be detected (phase line N), at the moment, a zero-crossing signal (voltage of the second end of the second resistor R2) is relatively positive voltage to the ground, the positive voltage changes along with positive half-wave change of the sine waves, the positive voltage is in a trend of increasing first and then reducing, but under the action of a voltage stabilizing diode D3, the zero-crossing signal is clamped to be a voltage stabilizing value of the voltage stabilizing diode D3, but when the positive half-wave is just increased and is reduced to be close to 0V, the voltage between the phase line L and the phase line N is close to 0V, the voltage stabilizing diode D3 fails to meet the condition of reverse breakdown, at the moment, the zero-crossing signal receiving circuit detects the zero-crossing signal is close to 0V, and therefore the zero-crossing signal receiving circuit detects two low levels with shorter duration in the positive half cycle;
b2, when the sine wave input by the line pair to be tested is in the negative half cycle, under the forward conduction action of the zener diode D3, the positive conduction voltage of the zener diode D3 is clamped between the port for receiving the zero-crossing signal in the zero-crossing signal receiving circuit and the ground, and the positive conduction voltage is negative relative to the ground, so that the zero-crossing signal receiving circuit can detect continuous low level in the negative half cycle; similarly, the zero-crossing signal receiving circuit can determine the zero-crossing timing by analyzing the level change of the detected zero-crossing signal. The utility model also provides a zero-crossing detection device, which comprises the zero-crossing detection circuit provided by the embodiment of the utility model.
The utility model has the following beneficial effects: by a zero crossing detection circuit, comprising: the device comprises a signal generating unit for generating a zero crossing signal according to the voltage of a to-be-tested pair, a clamping unit for clamping the upper limit and the lower limit of the voltage of the zero crossing signal, and a pull-up unit for providing pull-up voltage for the output end of the signal generating unit; the utility model has the advantages of simple circuit structure, low cost, low power consumption, high reliability and the like, and can also prevent the zero-crossing signal receiving circuit from being damaged due to the overcurrent or overvoltage of the zero-crossing signal.
It is to be understood that the above examples only represent preferred embodiments of the present utility model, which are described in more detail and are not to be construed as limiting the scope of the utility model; it should be noted that, for a person skilled in the art, the above technical features can be freely combined, and several variations and modifications can be made without departing from the scope of the utility model; therefore, all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (10)
1. A zero-crossing detection circuit, comprising:
the signal generation unit (1) is used for generating a zero crossing signal according to the voltage of the to-be-tested line pair, the input end of the signal generation unit is connected with the first to-be-tested line of the to-be-tested line pair, and the output end of the signal generation unit is connected with the zero crossing signal receiving circuit so as to output the zero crossing signal to the zero crossing signal receiving circuit;
the clamping unit (2) is used for clamping the upper and lower voltage limits of the zero crossing signal and is connected with the output end of the signal generating unit (1) and a second to-be-tested line in the to-be-tested line pair;
and the pull-up unit (3) is used for pulling up the output end of the signal generation unit (1) and is connected with the output end of the signal generation unit (1).
2. The zero crossing detection circuit according to claim 1, wherein the signal generating unit (1) comprises a first resistor and a second resistor; the first end of the first resistor is used as an input end of the signal generating unit (1), the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is an output end of the signal generating unit (1).
3. Zero crossing detection circuit according to claim 1, characterized in that the pull-up unit (3) comprises a third resistor; the output end of the signal generating unit (1) is connected to a direct current voltage through the third resistor.
4. Zero crossing detection circuit according to claim 1, further comprising a current limiting unit (4); the output end of the signal generating unit (1) is connected with the input end of the current limiting unit (4), and the output end of the current limiting unit (4) is connected with the zero crossing signal receiving circuit.
5. Zero crossing detection circuit according to claim 4, characterized in that the current limiting unit (4) comprises a fourth resistor; the output end of the signal generating unit (1) is connected to the zero crossing signal receiving circuit through the fourth resistor.
6. Zero crossing detection circuit according to claim 4, further comprising a filtering unit (5); the output end of the current limiting unit (4) is connected to the ground through the filtering unit (5).
7. Zero crossing detection circuit according to claim 6, characterized in that the filtering unit (5) comprises a first capacitance; the output end of the current limiting unit (4) is connected to the ground through the first capacitor.
8. Zero crossing detection circuit according to any one of claims 1 to 7, characterized in that the clamping unit (2) comprises a first diode and a second diode; the anode of the first diode and the cathode of the second diode are connected with the output end of the signal generating unit (1), the cathode of the first diode is connected with direct-current voltage, and the anode of the second diode is connected with the second to-be-tested line and ground.
9. Zero crossing detection circuit according to any one of claims 1 to 7, characterized in that the clamping unit (2) comprises a zener diode; the anode of the voltage stabilizing diode is connected with the second to-be-tested line and the ground, and the cathode of the voltage stabilizing diode is connected with the output end of the signal generating unit (1).
10. A zero-crossing detection apparatus comprising the zero-crossing detection circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223353991.0U CN219496518U (en) | 2022-12-14 | 2022-12-14 | Zero-crossing detection circuit and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223353991.0U CN219496518U (en) | 2022-12-14 | 2022-12-14 | Zero-crossing detection circuit and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219496518U true CN219496518U (en) | 2023-08-08 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223353991.0U Active CN219496518U (en) | 2022-12-14 | 2022-12-14 | Zero-crossing detection circuit and device |
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| Country | Link |
|---|---|
| CN (1) | CN219496518U (en) |
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2022
- 2022-12-14 CN CN202223353991.0U patent/CN219496518U/en active Active
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