Comparison circuit, comparator and electrical equipment

Abstract

The invention provides a comparison circuit, a comparator and electrical equipment. A switch unit is arranged between a first signal input unit and a signal output unit and is used for adjusting the connection state between the first signal input unit and the signal output unit by changing the on-off state of the switch unit; when the switch unit is in an off state and the level of the second signal is greater than the level of the first preset signal, the switching unit switches the switch unit to an on state based on the control signal; when the switch unit is in the on state and the level of the second signal is smaller than the level of the second preset signal, the switching unit switches the switch unit to the off state based on the control signal; the level of the first preset signal is greater than that of the second preset signal; when the on-off state of the switch unit is switched, the second signal is firstly changed between the first preset signal and the second preset signal, and at the moment, the switch unit is still kept in the current on-off state, so that hysteresis control of output of the comparison circuit can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of comparison circuits, and particularly relates to a comparison circuit, a comparator, and an electrical appliance. BACKGROUND

[0002] A comparator is a circuit used for detecting the level of an input signal, and its output state will jump (e.g., from low to high) when the input signal reaches a preset threshold. This feature makes it widely used in voltage detection, signal triggering, and logic control scenarios.

[0003] The output of the comparator in the related art will rapidly switch with a slight change in the input signal. Although such rapid response helps to monitor signal changes in real time, it also makes it extremely sensitive to noise or interference. For example, if the input signal fluctuates near the threshold (e.g., power supply noise or environmental interference), the output signal will frequently jump, thereby causing false actions or system instability. SUMMARY

[0004] The application aims to provide a comparison circuit, a comparator, and an electrical appliance, and aims to solve the problem that the comparison circuit in the prior art cannot be self-checked.

[0005] A first aspect of an embodiment of the application provides a comparison circuit, which comprises: a first signal input unit configured to output a first signal; a signal output unit configured to output a comparison signal based on the connection state between the first signal input units; a switch unit arranged between the first signal input unit and the signal output unit and configured to adjust the connection state between the first signal input unit and the signal output unit by changing the on-off state of the switch unit; a switching unit configured to switch the on-off state of the switch unit based on a control signal; a second signal input unit configured to output a second signal to the switching unit, the second signal being related to the control signal; wherein, in the case that the switch unit is in an off state and the level of the second signal is greater than the level of a first preset signal, the switching unit switches the switch unit to an on state based on the control signal; in the case that the switch unit is in an on state and the level of the second signal is less than the level of a second preset signal, the switching unit switches the switch unit to an off state based on the control signal; and the level of the first preset signal is greater than the level of the second preset signal.

[0006] In some embodiments of the present application, the control signal is related to the second signal when the switch unit is in the off state, and the control signal is related to the second signal and the third signal when the switch unit is in the on state.

[0007] In some embodiments of the present application, the control signal is the second signal when the switch unit is in the off state, and the control signal is the sum of the second signal and the third signal when the switch unit is in the on state.

[0008] In some embodiments of the present application, the third signal is the comparison signal.

[0009] In some embodiments of the present application, the switch unit comprises a first transistor, a first end of the first transistor is connected to the first signal input unit, a second end of the first transistor is connected to the signal output unit, and a control electrode of the first transistor is connected to the first end. The switching unit comprises a three-terminal voltage regulator, a first end of the three-terminal voltage regulator is connected to the control electrode of the first transistor, a second end of the three-terminal voltage regulator is grounded, and a control electrode of the three-terminal voltage regulator is connected to the second signal input unit.

[0010] In some embodiments of the present application, the switching unit further comprises a diode, a positive electrode of the diode is connected to the signal output unit, and a negative electrode of the diode is connected to the control electrode of the three-terminal voltage regulator.

[0011] In some embodiments of the present application, the second signal input unit comprises a first voltage dividing resistor and a second voltage dividing resistor connected in series, the first voltage dividing resistor is used to access an initial signal, and the second voltage dividing resistor is grounded; the control electrode of the three-terminal voltage regulator is connected between the first voltage dividing resistor and the second voltage dividing resistor to obtain the second signal.

[0012] In some embodiments of the present application, the number of first voltage dividing resistors is three, and the three first voltage dividing resistors are connected in series.

[0013] In some embodiments of the present application, the comparison circuit further comprises a first capacitor, one end of the first capacitor is connected to the control electrode of the three-terminal voltage regulator, and the other end of the first capacitor is grounded. And / or, the comparison circuit further comprises a second capacitor, one end of the second capacitor is connected to the first end of the first transistor, and the other end of the second capacitor is connected to the control electrode of the first transistor.

[0014] In some embodiments of the present application, the first signal is a high level signal, and the comparison signal is a high level signal related to the first signal when the switch unit is in the on state; and the comparison signal is a low level signal when the switch unit is in the off state.

[0015] In a second aspect of the embodiments of the present application, a comparator is further provided, which comprises the comparison circuit as described above.

[0016] In a third aspect of the embodiments of the present application, an electrical appliance is further provided, which comprises the comparator as described above.

[0017] The comparison circuit, the comparator and the electrical appliance provided by the present application have the following beneficial effects: the comparison circuit comprises a first signal input unit, a signal output unit, a switch unit, a switching unit and a second signal input unit; the first signal input unit is configured to output a first signal; the signal output unit is configured to output a comparison signal based on a connection state between the first signal input unit; the switch unit is arranged between the first signal input unit and the signal output unit, and is configured to adjust the connection state between the first signal input unit and the signal output unit by changing a connection state of the switch unit; the switching unit is configured to switch the connection state of the switch unit based on a control signal; and the second signal input unit is configured to output a second signal to the switching unit, the second signal being related to the control signal; wherein, when the switch unit is in the off state and the level of the second signal is greater than the level of a first preset signal, the switching unit switches the switch unit to the on state based on the control signal; when the switch unit is in the on state and the level of the second signal is less than the level of a second preset signal, the switching unit switches the switch unit to the off state based on the control signal; and the level of the first preset signal is greater than the level of the second preset signal; by setting the level of the first preset signal to be greater than the level of the second preset signal, when the connection state of the switch unit is switched, the second signal will first change to between the first preset signal and the second preset signal, and at this time, the switch unit still maintains the current connection state, which is conducive to realizing hysteresis control of the comparison circuit. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A schematic diagram of a framework structure of a comparison circuit according to an embodiment of the present application is shown in FIG. 1; Figure 2 A schematic diagram of a circuit structure of a comparison circuit according to an embodiment of the present application is shown in FIG. 2; Figure 3 A schematic diagram of a second signal and a comparison signal according to an embodiment of the present application is shown in FIG. 3.

[0019] Specific element symbol explanation: 100 - first signal input unit, 200 - signal output unit, 300 - switch unit, 400 - switching unit, 500 - second signal input unit, Vin - second signal, VCC - first signal, Q100 - first transistor, Vout - comparison signal, IC100 - three-terminal voltage regulator, D100 - diode, R103 - second voltage dividing resistor, C100 - first capacitor, C101 - second capacitor. DETAILED DESCRIPTION

[0020] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0021] It should be noted that when an element is referred to as "being disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "being connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0022] In addition, the terms "first", "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0023] It should be noted that the comparator is a key component in electronic circuits, and its core function is to receive input signals and output corresponding response signals according to pre-set logic rules. Specifically, when the amplitude of the input signal reaches or crosses a certain threshold voltage, the internal logic of the comparator will trigger a significant change in the output state, that is, an output jump occurs. This process realizes accurate detection and immediate response to input signals, and is widely used in signal processing, automatic control, data conversion and other fields.

[0024] However, in the related art, one of the significant features of the comparator is that the output signal thereof is extremely sensitive to the change of the input signal. This means that once any variation occurs in the input signal, whether it is a positive increase or a negative decrease, as long as the variation reaches or crosses a preset threshold value, the output state of the comparator will immediately make a corresponding adjustment, resulting in a very high switching rate of the output signal. This characteristic of fast switching indeed improves the response sensitivity and processing speed of the circuit to some extent, especially in scenarios that require fast decision-making or high-frequency operation. However, at the same time, this highly sensitive output switching mechanism also exposes the disadvantage of weak anti-interference ability.

[0025] Specifically, when the input signal encounters a small fluctuation near the threshold voltage, which may be caused by noise or external interference, the comparator often mistakenly considers these unexpected signal changes as valid input changes, thereby triggering unnecessary output state jumps. Such frequent and unintentional output variations not only significantly reduce the overall stability and reliability of the circuit, as they can mislead the subsequent circuit to make incorrect judgments or operations, but also can cause serious interference and impact to the system that relies on the accurate control or measurement of the comparator output signal, and even lead to system performance degradation or failure.

[0026] Based on this, the present application improves the comparator circuit, the comparator and the electrical equipment in the related art.

[0027] Please refer to Figure 1 , Figure 1A framework structure schematic diagram of a comparison circuit provided by an embodiment of the application is shown. The comparison circuit of the embodiment of the application comprises a first signal input unit 100, a signal output unit 200, a switch unit 300, a switching unit 400, and a second signal input unit 500. The first signal input unit 100 is configured to output a first signal VCC. The signal output unit 200 is configured to output a comparison signal Vout based on a connection state between the first signal input unit 100. The switch unit 300 is arranged between the first signal input unit 100 and the signal output unit 200, and is configured to adjust the connection state between the first signal input unit 100 and the signal output unit 200 by changing a conduction state of the switch unit 300. The switching unit 400 is configured to switch the conduction state of the switch unit 300 based on a control signal. The second signal input unit 500 is configured to output a second signal Vin to the switching unit 400, and the second signal Vin is related to the control signal. In a case where the switch unit 300 is in a disconnected state and a level of the second signal Vin is greater than a level of a first preset signal, the switching unit 400 switches the switch unit 300 to a connected state based on the control signal. In a case where the switch unit 300 is in the connected state and the level of the second signal Vin is less than a level of a second preset signal, the switching unit 400 switches the switch unit 300 to the disconnected state based on the control signal. The level of the first preset signal is greater than the level of the second preset signal.

[0028] It should be explained that the comparison circuit is an electronic circuit for comparing the level of an input signal and outputting a corresponding signal according to the comparison result, which is widely used in signal detection, threshold judgment, automatic control, and the like, and the output state is triggered by the difference in signal level. The first signal input unit 100 is a functional module for providing an initial input signal (the first signal VCC) in the comparison circuit, which can be formed by a power supply. The signal output unit 200 is a module for outputting a comparison signal Vout based on the connection state of the first signal input unit 100 and the signal output unit 200, and the level state (high level / low level) of the comparison signal Vout directly reflects the comparison result. The switch unit 300 is a conduction control component arranged between the first signal input unit 100 and the signal output unit 200, which includes a common type such as a triode, a MOS tube, a relay, and the like, and adjusts the path conduction of the signal transmitted from the first signal input unit 100 to the signal output unit 200 by changing the conduction or disconnection state of the switch unit 300.

[0029] The switching unit 400 is a functional module that receives an external signal and generates a control signal to switch the on-off state of the switching unit 300, and ensures that the switching unit 300 completes state switching according to the preset conditions based on the characteristics (such as the level high or low, the pulse signal) of the input control signal. The second signal input unit 500 is a module that provides the second signal Vin to the switching unit 400, and the level change is directly related to the control signal, which is the key basis for the switching unit 400 to determine whether to switch the state of the switching unit 300. The first preset signal is a high-level threshold signal preset by the switching unit 400, which is used to determine whether the second signal Vin meets the condition for switching the switching unit 300 from off to on, and the level value is set according to the functional requirements of the circuit, which is the "start threshold" for triggering the switching unit 300 to turn on. The second preset signal is a low-level threshold signal preset by the switching unit 400, which is used to determine whether the second signal Vin meets the condition for switching the switching unit 300 from on to off, and the level value is lower than the first preset signal, which is the "close threshold" for triggering the switching unit 300 to turn off.

[0030] It can be understood that the difference between the first preset signal and the second preset signal in the embodiment can provide a buffer interval for the slight fluctuation of the second signal Vin, which is beneficial to avoid frequent changes in the output state. If only a single threshold signal is set, when the second signal Vin slightly changes near the threshold value due to external interference (such as voltage fluctuation, electromagnetic noise), the switching unit 300 will repeatedly switch the on-off state, causing the comparison signal Vout output by the signal output unit 200 to fluctuate frequently, affecting the stable operation of the subsequent circuit. However, in the present embodiment, the first preset signal level is greater than the second preset signal level, and when the second signal Vin changes between the first preset signal and the second preset signal, the switching unit 300 maintains the current on-off state; for example, when the switching unit 300 is in the on state, even if the second signal Vin slightly decreases due to interference above the second preset signal, but does not decrease below the second preset signal, the switching unit 300 still remains on, and the signal output unit 200 will not change the comparison signal Vout due to slight interference; similarly, when the switching unit 300 is off, the second signal Vin rises slightly and does not reach the first preset signal, and the switching unit 300 still remains off. This buffering effect can reduce the influence of external interference on the circuit output, solve the problem of weak anti-interference ability of traditional single threshold circuit, and is beneficial to improve the stability of the comparison signal Vout.

[0031] Specifically, the hysteresis control helps to ensure that the output state switching of the comparison circuit has inertia, i.e., can avoid false triggering caused by instantaneous changes in the input signal. In practical applications, the second signal Vin may have instantaneous fluctuations (such as level jumps in a short period of time) due to load changes, signal transmission delays, and other factors. If the circuit is not designed with hysteresis, such instantaneous fluctuations are likely to be misjudged as valid signals, leading to false switching of the switching unit 300. In the embodiment, the switching unit 300 needs to switch from off to on when the second signal Vin reaches a higher first preset signal, and needs to switch from on to off when the second signal Vin falls to a lower second preset signal. The threshold difference between the two switching forms a "hysteresis interval". Even if the second signal Vin has a situation of falling back after temporarily exceeding the first preset signal or rising back after temporarily falling below the second preset signal, as long as it does not remain stable in the corresponding threshold range, the switching unit 300 will not be falsely switched. For example, in the fan start-stop control scenario, the second signal Vin is a temperature detection signal, the first preset signal corresponds to the fan start temperature, and the second preset signal corresponds to the fan stop temperature. If the temperature temporarily exceeds the start temperature due to environmental fluctuations and then falls back, the fan will not be falsely started. If the temperature temporarily falls below the stop temperature and then rises back, the fan will not be falsely stopped, ensuring that the device operates stably according to actual needs and avoiding device wear and energy waste caused by frequent start-stop.

[0032] In some embodiments of the present application, when the switching unit 300 is in the off state, the control signal is related to the second signal Vin; when the switching unit 300 is in the on state, the control signal is related to the second signal Vin and the third signal.

[0033] It can be understood that the role of the third signal in widening the difference between the first and second preset signals can achieve dynamic adjustment of the hysteresis range, solving the application limitations caused by the fixed threshold difference of traditional circuits. In the embodiment, the third signal serves as the basis for widening the difference between the two preset signals, and the difference size can be flexibly adjusted by changing the level or associated logic of the third signal. For example, when the third signal is the feedback voltage of the signal output unit 200, increasing the level of the third signal can simultaneously raise the first preset signal or lower the second preset signal, thereby increasing the difference between the two signals and widening the hysteresis interval. Conversely, when the level of the third signal is lowered, the difference is reduced and the hysteresis interval is narrowed. This dynamic adjustment capability enables the circuit to flexibly switch the hysteresis range according to the scene requirements (such as wide interval for high-interference environment and narrow interval for precise control).

[0034] In some embodiments of the present application, when the switching unit 300 is in the off state, the control signal is the second signal Vin; when the switching unit 300 is in the on state, the control signal is the sum of the second signal Vin and the third signal.

[0035] It can be understood that by differentiating the control signal in different states of the switch unit 300, the threshold condition of the circuit conduction and disconnection can be clearly distinguished, a stable hysteresis interval is formed, and the problem of frequent state jumping caused by the fuzzy threshold of the traditional circuit is solved. When the switch unit 300 is disconnected, the control signal is only the second signal Vin, at this time the threshold of the circuit conduction (the first preset signal) is directly related to the second signal Vin, and only when the second signal Vin reaches the first preset signal, the switch unit 300 can be triggered to conduct, ensuring the accuracy of the conduction threshold; when the switch unit 300 is conducting, the control signal is the sum of the second signal Vin and the third signal, since the third signal is a signal participating in the positive direction (such as a positive voltage feedback signal), the value of the superimposed control signal is higher than the single second signal Vin, at this time the threshold of the circuit disconnection (the second preset signal) needs to be judged based on the superimposed signal, that is, the sum of the second signal Vin and the third signal needs to be reduced to below the second preset signal, and the switch unit 300 will be disconnected, and due to the presence of the third signal, the actual value of the corresponding second signal Vin at this time will be lower than the conduction threshold (the first preset signal) when the switch unit 300 is disconnected, forming a hysteresis interval of "the conduction threshold is higher than the disconnection threshold".

[0036] In some embodiments of the present application, the third signal is a comparison signal Vout.

[0037] It can be understood that taking the comparison signal Vout as the third signal can make the hysteresis interval adjust in real time with the circuit output state (comparison signal Vout), avoiding the problem that the fixed hysteresis interval cannot adapt to the change of the circuit working condition. The comparison signal Vout directly reflects the working state of the circuit - when the comparison signal Vout is high, it means that the circuit is in a stable conduction output state, at this time the control signal is the sum of the second signal Vin and the high-level comparison signal Vout, the value of the superimposed control signal is higher, and the corresponding switch unit 300 disconnection threshold (the second preset signal) needs to meet a higher superimposed signal condition, that is, the second signal Vin needs to be reduced to a lower level to trigger disconnection, and the hysteresis interval is widened; if the comparison signal Vout fluctuates slightly due to changes in load and the like, the superimposed control signal adjusts synchronously, and the hysteresis interval also dynamically narrows, ensuring that the circuit can match the adaptive hysteresis range under different output states.

[0038] In some embodiments of the present application, please refer to Figure 2 , Figure 2The circuit structure schematic diagram of the comparison circuit provided by the embodiment is shown, the switch unit 300 of the embodiment includes a first transistor Q100, a first end of the first transistor Q100 is connected with the first signal input unit 100, and a second end of the first transistor Q100 is connected with the signal output unit 200; a control electrode of the first transistor Q100 is connected on the first end; the switching unit 400 includes a three-terminal voltage regulator IC100, a first end of the three-terminal voltage regulator IC100 is connected with the control electrode of the first transistor Q100, a second end of the three-terminal voltage regulator IC100 is grounded, and a control electrode of the three-terminal voltage regulator is connected with the second signal input unit 500.

[0039] It needs to be explained that the first transistor Q100 is a core semiconductor device constituting the switch unit 300, belongs to an electronic element with current amplification or on-off control function, generally includes three electrodes (the first end, the second end and the control electrode), and can adjust the conduction capacity between the first end and the second end through the signal of the control electrode, so as to realize the control of the on-off of the circuit. The three-terminal voltage regulator IC100 has three pins (the first end, the second end and the control electrode), the core function of which is to stabilize the output voltage or realize specific on-off control logic according to the signal of the control electrode, and whether to be turned on can be judged through the signal received by the control electrode, so as to adjust the electrical connection state between the first end and the second end.

[0040] It can be understood that the control electrode potential of the first transistor Q100 is linked with the first end potential, and the first end of the three-terminal voltage regulator IC100 is directly connected with the control electrode; when the three-terminal voltage regulator IC100 is turned on, the control electrode of the first transistor Q100 is grounded through the second end of the voltage regulator, the potential is reduced, at this time, the first end and the control electrode of the first transistor Q100 form a potential difference, which meets the transistor turn-on condition, and the path between the first signal input unit 100 and the signal output unit 200 is connected; when the three-terminal voltage regulator IC100 is not turned on, the control electrode of the first transistor Q100 has no grounding path, the potential is consistent with the first end, and there is no potential difference, at this time, the transistor is turned off, and the path between the first signal input unit 100 and the signal output unit 200 is disconnected.

[0041] In some embodiments of the present application, please continue to refer to Figure 2 The switching unit 400 of the embodiment further includes a diode D100, a positive electrode of the diode D100 is connected with the signal output unit 200, and a negative electrode of the diode D100 is connected with the control electrode of the three-terminal voltage regulator IC100.

[0042] It can be understood that the unidirectional conduction characteristic of the diode D100 can ensure that the signal of the signal output unit 200 can only be transmitted in a forward direction to the control electrode of the three-terminal voltage regulator IC100, avoiding interference of signal backflow in a reverse direction to the signal output unit 200, and ensuring stability of signal transmission of the circuit. The signal output unit 200 needs to output a stable comparison signal Vout to the outside. If the diode D100 is absent, the signal (such as reverse current generated by fluctuation of the second signal Vin) of the control electrode of the three-terminal voltage regulator IC100 can flow back to the signal output unit 200, causing abnormality of the comparison signal Vout level, and affecting work of a subsequent circuit. In the embodiment, the anode of the diode D100 is connected to the signal output unit 200, and the cathode is connected to the control electrode of the three-terminal voltage regulator IC100. Only the forward signal of the signal output unit 200 is allowed to be transmitted to the control electrode of the three-terminal voltage regulator IC100 through the diode D100. Reverse current is cut off by the diode D100, thereby completely blocking a signal backflow path, ensuring that the comparison signal Vout of the signal output unit 200 is not interfered by signals of the subsequent switching unit 400, and maintaining stable output of the comparison signal Vout.

[0043] In some embodiments of the present application, please refer to Figure 2 The second signal input unit 500 of the embodiment includes a first voltage dividing resistor and a second voltage dividing resistor R103 connected in series. The first voltage dividing resistor is used to access an initial signal, and the second voltage dividing resistor R103 is grounded. The control electrode of the three-terminal voltage regulator IC100 is connected between the first voltage dividing resistor and the second voltage dividing resistor R103, so as to obtain the second signal Vin.

[0044] It can be understood that the first voltage dividing resistor and the second voltage dividing resistor R103 connected in series can accurately control the level range of the second signal Vin by adjusting the resistance ratio, so as to ensure that it is adapted to the reference voltage requirement of the three-terminal voltage regulator IC100, and solve the control deviation problem caused by inadaptation of the initial signal voltage. The voltage range of the initial signal (such as a power supply voltage or a sensor output signal) can be far beyond the adaptation range of the control electrode of the three-terminal voltage regulator IC100 (such as the reference voltage of the three-terminal voltage regulator IC100 is 2.5 V, and the initial signal is 12 V). If it is directly input, the three-terminal voltage regulator IC100 can be damaged or control failure can occur. In the present setting, the first voltage dividing resistor and the second voltage dividing resistor R103 form a series voltage dividing loop. By changing the resistance ratio of the two resistors (such as the first voltage dividing resistor is 9.5 kΩ, and the second voltage dividing resistor R103 is 2.5 kΩ), the 12 V initial signal can be accurately divided into the 2.5 V second signal Vin, which is exactly matched with the reference voltage of the three-terminal voltage regulator IC100. If it is necessary to adjust the trigger threshold of the second signal Vin, only the resistance ratio of the two resistors needs to be changed (such as increasing the resistance of the first voltage dividing resistor to reduce the second signal Vin after voltage division, or decreasing the resistance to increase the second signal Vin after voltage division), without the need to replace the three-terminal voltage regulator IC100 or the initial signal source, thereby achieving flexible and accurate adjustment of the second signal Vin.

[0045] In some embodiments of the present application, please refer to Figure 2 , the number of the first voltage dividing resistors in the embodiment is three, and the three first voltage dividing resistors are connected in series. For example, the three first voltage dividing resistors are resistor R100, resistor R101 and resistor R102 respectively.

[0046] In some embodiments of the present application, the comparison circuit further comprises a first capacitor C100, one end of the first capacitor C100 is connected to the control electrode of the three-terminal voltage regulator IC100, and the other end of the first capacitor C100 is grounded; and / or, the comparison circuit further comprises a second capacitor C101, one end of the second capacitor C101 is connected to the first end of the first transistor Q100, and the other end of the second capacitor C101 is connected to the control electrode of the first transistor Q100. In this way, it is beneficial to filter out the noise of the comparison circuit and improve the anti-misoperation performance of the comparison circuit.

[0047] In some embodiments of the present application, the first signal VCC is a high-level signal, in the case that the switching unit 300 is in the on state, the comparison signal Vout is a high-level signal related to the first signal VCC; in the case that the switching unit 300 is in the off state, the comparison signal Vout is a low-level signal.

[0048] In some embodiments of the present application, please refer to Figure 3 , Figure 3 The signal schematic diagram of the second signal Vin and the comparison signal Vout provided by the embodiment is shown. Figure 3 The horizontal coordinate is the signal value of the first signal VCC, and the vertical coordinate is the signal value of the comparison signal Vout. Vin1 is the second signal Vin required to flip the comparison signal Vout to high when the comparison signal Vout is a low-level signal (such as 0V), and Vin2 is the second signal Vin required to flip the comparison signal Vout to low when the comparison signal Vout is a high-level signal.

[0049] Taking the on voltage of the three-terminal voltage regulator IC100 as 2.5V and the first transistor Q100 as a triode as an example, when the comparison signal Vout is a low-level signal (such as 0V), the second signal Vin directly controls the three-terminal voltage regulator IC100, at this time the voltage VA of the control electrode of the three-terminal voltage regulator IC100 satisfies At this time, the three-terminal voltage regulator IC100 needs to be turned on to satisfy: .

[0050] When the second signal Vin is greater than Vin1 and VA ≥ 2.5V, the three-terminal regulator IC100 turns on. At this time, resistor R106 divides the voltage, and the first transistor Q100 turns on. Therefore, the voltage across resistor R106 is clamped at the forward voltage drop of VEB, which is 0.7V. Therefore, we can conclude that: .

[0051] Given that the voltage drop across transistor VEB is 0.7V, the voltage across VE can be calculated as follows: According to the working principle of a PNP transistor, with both the emitter junction and collector junction forward biased, the PNP transistor enters saturation conduction mode, and the voltage drop across VEC is 0.3V. Therefore, the voltage at point C is also the voltage at point Vout. .

[0052] When the comparison signal Vout is high, both the second signal Vin and the comparison signal Vout simultaneously control the three-terminal regulator IC100. The comparison signal Vout, through diode D100 and resistor R104, and the second signal Vin, through resistors R100, R101, R102, and R103, form a weighted feedback at point A. For the comparison signal Vout to flip to zero, the VA voltage needs to be less than 2.5V, but this cannot be achieved simply by the Vin voltage being less than Vin1.

[0053] Specifically, the voltage at point D is calculated by comparing the signal Vout with diode D100. The voltage drop across diode D100 is approximately 0.7V, from which the voltage V at point D can be derived. D : Based on the weighted feedback calculation method, V is calculated. D The weighted effect value of point A is represented by V. A1 The resistance of R100+R101+R102 and R103 connected in parallel is expressed as R L1 . ; According to the weighted feedback calculation method, the weighted effect of Vin on point A is expressed as V. A2 The resistance of resistors R103 and R104 connected in parallel is expressed as R. L2； The resistance of two resistors connected in parallel is less than either of the two resistors, RL2 < R103. .

[0054] Therefore, we can conclude that: Given the effects of weighted feedback VD and VIN on A: Given that voltage VA is less than 2.5V, the comparison signal Vout is toggled. The required voltage for VA2 can be calculated as follows: .

[0055] It can be concluded that when the comparison signal Vout is high, the corresponding Vin voltage when the comparison signal Vout flips to zero is: .

[0056] Since R L2 is less than R103, 2.5-V A1 is less than 2.5, it can be concluded that Vin2 is less than Vin1. As follows: .

[0057] According to the above description, it can be concluded that when the comparison signal Vout voltage is zero, if the comparison signal Vout voltage needs to flip to high, the second signal Vin voltage required at this time is Vin1. When the comparison signal Vout voltage is high, if the comparison signal Vout voltage needs to flip to zero, the second signal Vin voltage required at this time is Vin2. Vin2 is less than Vin1, forming hysteresis.

[0058] Further, in order to better implement the comparison circuit in any of the above embodiments, on the basis of the above comparison circuit, the embodiments of the present application also provide a comparator, which comprises the comparison circuit as described above.

[0059] Still further, in order to better implement the comparator in any of the above embodiments, on the basis of the above comparator, the embodiments of the present application also provide an electrical appliance, which comprises the comparator as described above.

[0060] In some embodiments, the electrical appliance is a fan, a power supply, etc.

[0061] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0062] The above has described the basic concept, and it is obvious that the above detailed disclosure is only taken as an example and does not constitute a limitation on the present application for those skilled in the art. Although it is not explicitly stated here, those skilled in the art can make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0063] Also, the use of "a" or "an" to describe an element of the application is merely for convenience and to aid in the understanding of the application. Unless otherwise stated, the use of "a" or "an" is not intended to limit the number of elements to one. Similarly, the use of "another" to describe an element of the application is not intended to limit the number of elements to one unless otherwise stated. Furthermore, the use of the term "another" to describe an element of the application is not intended to mean only a single element but multiple elements unless otherwise stated. Also, the use of the term "plurality" is intended to mean a number greater than one unless otherwise stated.

[0064] Similarly, it is to be noticed that the term "comprising", used in the description, is not intended to exclude other elements or steps. It is to be understood that the term "comprising" is not used in the sense of "consisting only of" or "consisting of". Furthermore, the use of the term "some" in the description is intended to mean "one or more". In addition, it is to be noticed that the term "some" is used in the sense of "one or more unless otherwise stated.

[0065] The above embodiments are only used to illustrate the technical solutions of the present application, but not intended to limit the present application; neither should the above description of the embodiments be regarded as a complete disclosure of the technical solutions of the present application. It should be understood by those skilled in the art that the technical solutions recorded in the above embodiments can be modified or equivalent replacements can be made to some of the technical features without departing from the spirit and scope of the technical solutions of the present application. These modifications and replacements should be included in the protection scope of the present application.

Claims

1. A comparison circuit [1] characterized by, The comparison circuit comprises: a first signal input unit for outputting a first signal; a signal output unit for outputting a comparison signal based on a connection state between the first signal input units; a switch unit arranged between the first signal input unit and the signal output unit and used for adjusting the connection state between the first signal input unit and the signal output unit by changing an on-off state of itself; a switching unit for switching the on-off state of the switch unit based on a control signal; a second signal input unit for outputting a second signal to the switching unit, the second signal being related to the control signal; wherein, in a case where the switch unit is in an off state and a level of the second signal is greater than a level of a first preset signal, the switching unit switches the switch unit to an on state based on the control signal; in a case where the switch unit is in an on state and the level of the second signal is less than a level of a second preset signal, the switching unit switches the switch unit to an off state based on the control signal; and the level of the first preset signal is greater than the level of the second preset signal.

2. The comparison circuit [2] of claim 1, wherein, In a case where the switch unit is in the off state, the control signal is related to the second signal; and in a case where the switch unit is in the on state, the control signal is related to the second signal and a third signal.

3. The comparison circuit [3] of claim 2, wherein, In a case where the switch unit is in the off state, the control signal is the second signal; and in a case where the switch unit is in the on state, the control signal is a sum of the second signal and the third signal.

4. The comparison circuit [4] of claim 2 or 3, characterized in that, The third signal is the comparison signal.

5. The comparison circuit [5] of claim 1, wherein, The switch unit comprises a first transistor, a first end of the first transistor being connected to the first signal input unit, a second end of the first transistor being connected to the signal output unit, and a control electrode of the first transistor being connected to the first end; The switching unit comprises a three-terminal voltage regulator, a first end of the three-terminal voltage regulator being connected to the control electrode of the first transistor, a second end of the three-terminal voltage regulator being grounded, and a control electrode of the three-terminal voltage regulator being connected to the second signal input unit.

6. The comparison circuit [6] of claim 5, wherein, The switching unit further comprises a diode, a positive electrode of the diode being connected to the signal output unit, and a negative electrode of the diode being connected to the control electrode of the three-terminal voltage regulator.

7. The comparison circuit [7] of claim 5, wherein, The second signal input unit comprises a first voltage dividing resistor and a second voltage dividing resistor connected in series, the first voltage dividing resistor being used for inputting an initial signal, and the second voltage dividing resistor being grounded; and the control electrode of the three-terminal voltage regulator is connected between the first voltage dividing resistor and the second voltage dividing resistor to obtain the second signal.

8. The comparison circuit [8] of claim 7, wherein, The number of the first voltage dividing resistors is three, and the three first voltage dividing resistors are connected in series.

9. The comparison circuit [9] of claim 5, wherein, The comparison circuit further comprises a first capacitor, one end of the first capacitor being connected to the control electrode of the three-terminal voltage regulator, and the other end of the first capacitor being grounded; and / or, the comparison circuit further comprises a second capacitor, one end of the second capacitor being connected to the first end of the first transistor, and the other end of the second capacitor being connected to the control electrode of the first transistor.

10. The comparison circuit [10] of claim 1, wherein, The first signal is a high level signal, and the comparison signal is a high level signal related to the first signal when the switch unit is in a conducting state; and the comparison signal is a low level signal when the switch unit is in a non-conducting state.

11. A comparator [11] characterized by The comparator comprises the comparison circuit according to any one of claims 1 to 10.

12. An electric appliance [12] characterized by comprising: The electric appliance comprises the comparator according to claim 11.

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