CN215991299U - Hysteresis circuit, emergency lighting circuit and lighting equipment - Google Patents
Hysteresis circuit, emergency lighting circuit and lighting equipment Download PDFInfo
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- CN215991299U CN215991299U CN202121919302.0U CN202121919302U CN215991299U CN 215991299 U CN215991299 U CN 215991299U CN 202121919302 U CN202121919302 U CN 202121919302U CN 215991299 U CN215991299 U CN 215991299U
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Abstract
The utility model discloses a hysteresis circuit, an emergency lighting circuit and lighting equipment. The hysteresis circuit includes: the voltage detection module is used for receiving an input voltage, generating a sampling voltage according to the input voltage and detecting the sampling voltage; the isolation coupling module is used for controlling an output signal of the isolation coupling module according to the sampling voltage; the voltage adjusting module is used for adjusting the sampling voltage; according to the hysteresis circuit, the sampling voltage related to the input voltage is detected, when the sampling voltage is detected to be reduced to the trigger action voltage point, the level corresponding to the output signal is controlled to turn over, and until the sampling voltage is detected to be increased to the reverse recovery voltage point, the level corresponding to the output signal is controlled to turn over again, so that the input voltage state can be judged timely and accurately, and the reliability and the safety of a product are further improved.
Description
Technical Field
The utility model relates to the technical field of lighting circuits, in particular to a hysteresis circuit, an emergency lighting circuit and lighting equipment.
Background
Illumination that is enabled due to a power failure for normal illumination is referred to as emergency illumination. Emergency lighting differs from general lighting in that it includes: standby lighting, evacuation lighting and safety lighting. Emergency lighting is an important safety facility for modern public and industrial buildings, and is closely related to personal safety and building safety. When a fire or other disasters happen to a building and the power supply is interrupted, emergency lighting plays an important role in evacuation of personnel, fire rescue work, important production, continuous operation of work or necessary operation and disposal.
At present, a power supply part of an emergency lighting lamp and an evacuation indication lamp is included in a fire-fighting emergency lighting and evacuation indication system. The non-centralized control type emergency lighting centralized power supply has the following provisions: when the main power supply voltage of the lamp works at any voltage within the range of 60% -80% of the rated voltage, the state indicator lamp and the relay of the emergency lighting centralized power supply are not required to be switched for many times, and if the state indicator lamp and the relay are switched for many times, the main power supply voltage of the lamp has the problems of inevitable ripples and instability.
Thus, the related art proposes a scheme as shown in fig. 1 to determine the condition of the main power voltage of the lamp. Referring to fig. 1, for a non-isolated power supply, the ADC sampled value is obtained by using the single chip U4, and the following logic judgment is performed: and judging whether the input voltage Vbus reaches a trigger action voltage point or not, and judging whether the input voltage Vbus reaches a reverse recovery voltage point or not when the normal work is recovered. The trigger action voltage point refers to a voltage value corresponding to a preset function (for example, triggering an emergency function), and the reverse recovery voltage point refers to a voltage value corresponding to a preset function before recovery (for example, recovery to normal operation).
The scheme has specific limitations, including that 1) only aiming at a non-isolated power supply, the input voltage and the singlechip are in common ground, and the scheme is suitable for application occasions with wider requirements on product safety design; 2) it is only suitable for the circuit with single chip microcomputer control and the proper ADC sampling value detection port.
Therefore, there is a need to address the problems of the prior art.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a hysteresis circuit, an emergency lighting circuit and lighting equipment, which aim to realize timely and accurate monitoring of the state of input voltage by detecting sampling voltage related to the input voltage, controlling the level corresponding to an output signal to turn over after detecting that the sampling voltage is reduced to a trigger action voltage point, and controlling the level corresponding to the output signal to turn over again after detecting that the sampling voltage is increased to a reverse recovery voltage point, so as to further improve the reliability and safety of products.
According to an aspect of the present invention, an embodiment of the present invention provides a hysteresis circuit, including: the voltage detection module is used for receiving an input voltage, generating a sampling voltage according to the input voltage and detecting the sampling voltage; the isolation coupling module is used for controlling an output signal of the isolation coupling module according to the sampling voltage; the voltage adjusting module is used for adjusting the sampling voltage; when the voltage detection module detects that the sampling voltage is smaller than a first set value, controlling an optical coupler in the isolation coupling module to be in an isolation state, so that an output signal of the isolation coupling module is a first level signal, and meanwhile, the voltage adjustment module starts to adjust the sampling voltage; when the detection voltage detects that the sampling voltage is greater than a second set value, the optical coupler is controlled to be in a coupling state, so that an output signal of the isolation coupling module is a second level signal, meanwhile, the voltage adjusting module stops adjusting the sampling voltage, wherein the second set value is greater than the first set value, the difference value of the second set value and the sampling voltage is greater than a preset threshold value, and the first level signal is different from the second level signal.
Optionally, the voltage detection module includes: the voltage stabilizer comprises a first voltage-dividing resistor, a second voltage-dividing resistor, a first capacitor and a voltage stabilizer; the first end of the first voltage-dividing resistor receives the input voltage, the second end of the first voltage-dividing resistor is connected with the first end of the second voltage-dividing resistor to form a first node, and the first voltage-dividing resistor and the second voltage-dividing resistor are used for dividing the input voltage so that the voltage of the first node is a sampling voltage; a first end of the second voltage-dividing resistor is electrically connected with a first end of the first capacitor and a first pin of the voltage stabilizer respectively, and a second end of the second voltage-dividing resistor is electrically connected with a second end of the first capacitor and a third pin of the voltage stabilizer respectively; the first end of the first capacitor is electrically connected with a first pin of the voltage stabilizer, and the second end of the first capacitor is electrically connected with a third pin of the voltage stabilizer; the second pin of the voltage stabilizer is connected with the isolation coupling module, the third pin of the voltage stabilizer is connected with a power ground, and the first pin of the voltage stabilizer is used for obtaining sampling voltage.
Optionally, when the sampling voltage obtained by the first pin of the voltage regulator is less than a first set value, the voltage regulator is in a cut-off state; and when the sampling voltage obtained by the first pin of the voltage stabilizer is greater than a second set value, the voltage stabilizer is in a conducting state.
Optionally, the isolation coupling module further comprises: a fifth resistor and a sixth resistor; a first end of the fifth resistor receives a first side power supply voltage, and a second end of the fifth resistor is electrically connected with a positive electrode of the light emitting diode on the primary side of the optical coupler; the first end of the sixth resistor is connected with a second side power supply voltage, and the second end of the sixth resistor is electrically connected with the collector electrode of the triode at the secondary side of the optical coupler; and the cathode of the light emitting diode at the primary side of the optical coupler is electrically connected with a second pin of the voltage stabilizer in the voltage detection module, and the emitter of the triode at the secondary side of the optical coupler is connected with a signal ground.
Optionally, the voltage adjustment module includes: the first voltage regulator tube, the seventh resistor, the eighth resistor, the ninth resistor and the first switch tube; a first end of the first voltage regulator tube is electrically connected with a first end of the seventh resistor, and a second end of the first voltage regulator tube is electrically connected with a second end of a fifth resistor in the isolation coupling module; the second end of the seventh resistor is electrically connected with the first end of the eighth resistor and the control end of the first switching tube respectively; the first end of the eighth resistor is electrically connected with the control end of the first switching tube, and the second end of the eighth resistor is electrically connected with the first end of the first switching tube; a first end of the ninth resistor is electrically connected with a first end of a second voltage-dividing resistor in the voltage detection module, and a second end of the ninth resistor is electrically connected with a second end of the first switching tube; the first end of the first switch tube is respectively connected with the second end of the second voltage-dividing resistor in the voltage detection module and the power ground.
Optionally, the second voltage-dividing resistor in the voltage detection module and the ninth resistor in the voltage adjustment module are variable resistors.
Alternatively, the first set value may be configured to be associated with the resistance value of the second voltage-dividing resistor; the second set value may be configured to be associated with a resistance value of the ninth resistor.
Optionally, a power ground connected to the primary side of the optocoupler through the voltage regulator in the voltage detection module is not common to a signal ground connected to the secondary side of the optocoupler.
According to another aspect of the present invention, an embodiment of the present invention provides an emergency lighting circuit, including: the rectifying circuit is used for converting input alternating current into direct current so as to provide the direct current to the hysteresis circuit; a hysteresis circuit according to any embodiment of the present invention; and the control circuit is used for controlling whether the indicator light or the relay works or not according to the output signal of the isolation coupling module in the hysteresis circuit.
According to a further aspect of the utility model, an embodiment of the utility model provides a lighting device comprising the emergency lighting circuit according to any of the embodiments of the utility model.
The hysteresis loop circuit, the emergency lighting circuit and the lighting equipment provided by the embodiment of the utility model aim to realize the hysteresis loop design of the input voltage detection by detecting the sampling voltage related to the input voltage, controlling the level corresponding to the output signal to turn over after the sampling voltage is detected to be reduced to a trigger action voltage point, and controlling the level corresponding to the output signal to turn over again until the sampling voltage is detected to be increased to a reverse recovery voltage point, so that the input voltage state can be timely and accurately monitored, the emergency lighting circuit can be ensured to work according to the specified requirement, and the reliability and the safety of the product are improved.
Drawings
The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.
Fig. 1 is a schematic diagram of a hysteresis circuit in the prior art.
Fig. 2 is a schematic diagram of a hysteresis circuit according to an embodiment of the present invention.
Fig. 3 is a circuit diagram of a hysteresis circuit according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of an emergency lighting circuit according to an embodiment of the present invention.
Fig. 5 is a schematic view of an illumination apparatus according to an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the utility model, and not restrictive of the full scope of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "first", "second" and "first" are used herein for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The following disclosure provides many different embodiments or examples for implementing different features of the utility model. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Fig. 2 is a schematic diagram of a hysteresis circuit according to an embodiment of the present invention.
Referring to fig. 2, an embodiment of the present invention provides a hysteresis circuit 1000, where the hysteresis circuit 1000 includes: a voltage detection module 110, configured to receive an input voltage Vbus, generate a sampling voltage VA according to the input voltage Vbus, and detect the sampling voltage VA; an isolation coupling module 120, configured to control an output signal Vbus _ c of the isolation coupling module 120 according to the sampling voltage; a voltage adjusting module 130, configured to adjust the sampling voltage VA; when the voltage detection module 110 detects that the sampling voltage VA is smaller than a first set value, the optocoupler U1 in the isolation coupling module 120 is controlled to be in an isolation state, so that the output signal Vbus _ c of the isolation coupling module 120 is a first level signal, and the voltage adjustment module 130 starts adjusting the sampling voltage VA; when the detection voltage detects that the sampling voltage VA is greater than a second set value, the optocoupler U1 is controlled to be in a coupled state, so that the output signal Vbus _ c of the isolating and coupling module 120 is a second level signal, and the voltage adjustment module 130 stops adjusting the sampling voltage VA, where the second set value is greater than the first set value, and a difference between the second set value and the first set value is greater than a preset threshold, and the first level signal is different from the second level signal.
By the design, hysteresis loop design for detecting the input voltage can be realized, so that the state of the input voltage can be timely and accurately judged, and the corresponding emergency lighting circuit can be ensured to normally work according to the specified requirement, so that the reliability and the safety of the lighting equipment are improved.
The structure of the hysteresis circuit 1000 is further described below in conjunction with fig. 3.
Referring to fig. 2 and 3, an embodiment of the utility model provides a hysteresis circuit 1000, where the hysteresis circuit 1000 includes: a voltage detection module 110, an isolation coupling module 120, and a voltage adjustment module 130.
Specifically, the voltage detection module 110 may include: the first voltage-dividing resistor, the second voltage-dividing resistor, the first capacitor C1 and the voltage stabilizer U2. The first end of the first voltage-dividing resistor receives the input voltage, the second end of the first voltage-dividing resistor is connected with the first end of the second voltage-dividing resistor to form a first node A, and the first voltage-dividing resistor and the second voltage-dividing resistor are used for dividing the input voltage so that the voltage of the first node A is a sampling voltage. In this embodiment, the first divider resistor may include a first resistor R1, a second resistor R2, and a third resistor R3, but in some other embodiments, the first divider resistor may include a plurality of resistors, or may include only one resistor. The second voltage-dividing resistor is a fourth resistor R4 (which will be described later). As shown in fig. 2, in particular, a first terminal of the first resistor R1 receives the input voltage Vbus, and a second terminal of the first resistor R1 is electrically connected to a first terminal of the second resistor R2. A second end of the second resistor R2 is electrically connected to a first end of the third resistor R3, and a second end of the third resistor R3 is electrically connected to a first end of the fourth resistor R4, a first end of the first capacitor C1, and a first pin of the regulator U2, respectively. A first end of the fourth resistor R4 is electrically connected to the first end of the first capacitor C1 and the first pin of the voltage regulator U2, respectively, and a second end of the fourth resistor R4 is electrically connected to the second end of the first capacitor C1 and the third pin of the voltage regulator U2, respectively. The first end of the first capacitor C1 is electrically connected to the first pin of the regulator U2, and the second end of the first capacitor C1 is electrically connected to the third pin of the regulator U2. The second pin of the voltage regulator U2 is connected to the isolation coupling module 120, and the third pin of the voltage regulator U2 is connected to power ground.
In the voltage detection module 110, the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are connected in series in sequence. The first resistor R1 receives an input voltage Vbus. The input voltage Vbus may be a dc voltage, which may be obtained by a rectifying circuit in the emergency lighting circuit. In the embodiment, the resistances of the first resistor R1, the second resistor R2 and the third resistor R3 are the same and different from the fourth resistor R4. The fourth resistor R4 and the three resistors (the first resistor R1, the second resistor R2, and the third resistor R3) divide the input voltage to obtain the sampling voltage VA at the first node a. As shown in fig. 3, namely, the voltage of the first node a is the sampled voltage VA, which is the same hereinafter. Meanwhile, the voltage obtained from the first pin of the voltage regulator U2 is the sampled voltage VA. When the sampling voltage obtained by the first pin of the voltage stabilizer U2 is smaller than a first set value, the voltage stabilizer U2 is in a cut-off state; when the sampled voltage obtained at the first pin of the regulator U2 is greater than a second predetermined value, the regulator U2 is turned on. Therefore, the voltage regulator U2 may be considered a switching element.
Further, the first capacitor C1 is connected in parallel with the fourth resistor R4, and is used for filtering the voltage signal received by the first pin of the voltage regulator U2. In this embodiment, the voltage regulator U2 may be a TL431M type voltage regulator, and the internal reference voltage of the voltage regulator U2 is 2.5V. If other types of regulators are used, their internal reference voltages may be different.
The isolation coupling module 120 includes: a fifth resistor R5, a sixth resistor R6 and an optocoupler U1. A first end of the fifth resistor R5 receives a first side supply voltage VF, and a second end of the fifth resistor R5 is electrically connected to an anode of the led at the primary side of the optocoupler U1. The first end of the sixth resistor R6 is connected with a second side supply voltage VDD, and the second end of the sixth resistor R6 is electrically connected with the collector of the triode at the secondary side of the optocoupler U1. The cathode of the light emitting diode on the primary side of the optical coupler U1 is electrically connected with the second pin of the voltage stabilizer U2 in the voltage detection module 110, and the emitter of the triode on the secondary side of the optical coupler U1 is connected with the signal ground.
In the present embodiment, the optical coupler U1 is an EL817 type optical coupler, but is not limited thereto. When the light emitting diode on the primary side of the optical coupler U1 is turned on, the triode on the secondary side works normally, so that the optical coupler U1 is in a coupling state. When the light emitting diode on the primary side of the optocoupler U1 is turned off, the triode on the secondary side does not work, so that the optocoupler U1 is in an isolated state.
It should be noted that the first side supply voltage VF received by the first end of the fifth resistor R5 and the second side supply voltage VDD received by the first end of the sixth resistor R6 are both fixed supply voltages. In addition, in this embodiment, the primary side of the optocoupler U1 is not connected to the signal ground connected to the secondary side of the optocoupler U1 through the power ground connected to the voltage regulator U2 in the voltage detection module 110. Of course, in some other embodiments, the power ground and the signal ground may be common ground (applicable to non-isolated power).
With continued reference to fig. 2 and 3, the voltage adjustment module 130 includes: the circuit comprises a first voltage regulator tube ZD1, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a first switch tube Q1. A first terminal of the first regulator ZD1 is electrically connected to a first terminal of the seventh resistor R7, and a second terminal of the first regulator ZD1 is electrically connected to a second terminal of the fifth resistor R5 in the isolation coupling module 120. A second end of the seventh resistor R7 is electrically connected to the first end of the eighth resistor R8 and the control end of the first switch Q1, respectively. A first end of the eighth resistor R8 is electrically connected to the control end of the first switch transistor Q1, and a second end of the eighth resistor R8 is electrically connected to the first end of the first switch transistor Q1. A first end of the ninth resistor R9 is electrically connected to a first end of the fourth resistor R4 in the voltage detection module 110, and a second end of the ninth resistor R9 is electrically connected to a second end of the first switch tube Q1. A first end of the first switch Q1 is connected to a second end of the fourth resistor R4 in the voltage detection module 110 and a power ground, respectively.
In this embodiment, the ninth resistor R9 is connected in series with the first switch Q1 and then connected in parallel with the fourth resistor R4. When the first switch Q1 is turned on, its on-resistance is connected in series with the ninth resistor R9 and then in parallel with the fourth resistor R4. When the first switch Q1 is in the off state, the resistance is very large, and after the first switch Q1 is connected in series with the ninth resistor R9, the influence on the resistance of the parallel fourth resistor R4 is negligible. In other words, when the first switch Q1 is in an on state, the ground resistance of the first pin of the voltage regulator U2 is an equivalent resistance corresponding to the fourth resistor R4 connected in parallel with the on resistances of the ninth resistor R9 and the first switch Q1, and when the first switch Q1 is in an off state, the resistance of the first switch Q1 is very large, so the ground resistance of the first pin of the voltage regulator U2 is the fourth resistor R4. Thus, the resistance to ground of the first pin of the voltage regulator U2 when the first switch Q1 is turned on is smaller than the resistance to ground of the first pin of the voltage regulator U2 when the first switch Q1 is turned off.
Optionally, in this embodiment, the fourth resistor R4 in the voltage detection module 110 and the ninth resistor R9 in the voltage adjustment module 130 are variable resistors. When the input voltage is unchanged and the resistance value of the fourth resistor R4 is increased, the sampling voltage VA is increased. When the input voltage is not changed and the resistance of the fourth resistor R4 is decreased, the sampling voltage VA is decreased. Further, when the first switching transistor Q1 is in the on state, the hysteresis voltage decreases as the resistance value of the ninth resistor R9 increases. When the resistance of the ninth resistor R9 decreases, the hysteresis voltage increases, as will be explained further below. Therefore, the first set value (i.e., trigger voltage operating point) may be configured to be associated with the resistance value of the fourth resistor, and the second set value (i.e., reverse recovery voltage operating point) may be configured to be associated with the resistance value of the ninth resistor.
The operation of the hysteresis circuit 1000 will be further explained below.
When the input voltage Vbus is different, the sampling voltage VA changes accordingly. If the input voltage is high, the sampling voltage VA is high, and if the input voltage is low, the sampling voltage VA is low.
If the input voltage Vbus decreases gradually, the following conditions are met: when the sampling voltage VA is smaller than the internal reference voltage of the voltage regulator U2, and the sampling voltage VA reaches the trigger voltage operating point (i.e., the first set value), the voltage regulator U2 enters the off state, and then the led on the primary side of the optocoupler U1 is turned off (i.e., the off state), so that the optocoupler U1 is in the isolation state. When the optocoupler U1 is in the isolation state, the output signal Vbus _ c of the isolation coupling module 120 is a first level signal. In this embodiment, the first level signal is at a high level. Meanwhile, since the led at the primary side of the optocoupler U1 is in an off state, that is, the first pin of the optocoupler U1 shown in fig. 3 is at a high level, the first switch Q1 is in an on state, and thus, the on resistance thereof is connected in series with the ninth resistor R9 and then connected in parallel with the fourth resistor R4, so that the sampling voltage VA is reduced.
If the input voltage Vbus is changed from the original decrease to increase, and gradually increases. When the input voltage Vbus is restored to the original input voltage, the on-resistance of the first switch transistor Q1 is connected in series with the ninth resistor R9 and then connected in parallel with the fourth resistor R4, so that the sampling voltage VA is still lower than the internal reference voltage of the regulator U2.
Then, the input voltage Vbus continues to increase, when increasing to the following condition: when the sampled voltage VA is greater than the internal reference voltage of the voltage regulator U2, and the sampled voltage VA reaches the reverse recovery voltage point (i.e., the second set value), the voltage regulator U2 enters a conducting state, so that the light emitting diode on the primary side of the optocoupler U1 is in a conducting state, so that the optocoupler U1 is in a coupled state, and when the optocoupler U1 is in the coupled state, the output signal Vbus _ c of the isolation coupling module 120 is changed from the first level signal to the second level signal. In this embodiment, the second level signal is a low level signal, different from the first level signal. If the first level signal is a high level signal and the second level signal is a low level signal, the two signals are opposite signals. Therefore, the output signal Vbus _ c of the isolation coupling module 120 changes from high level to low level. Meanwhile, since the led on the primary side of the optocoupler U1 is in a conducting state, that is, the first pin of the optocoupler U1 shown in fig. 3 is at a low level, the first switching transistor Q1 is in an off state, so that the resistance of the first switching transistor Q1 is very large, and after the first switching transistor Q1 is connected in series with the ninth resistor R9, the influence on the resistance of the parallel fourth resistor R4 is negligible, so that the sampling voltage VA is increased. Thus, it can be further ensured that the sampled voltage VA is greater than the internal reference voltage of the voltage regulator U2, thereby keeping the output signal Vbus _ c of the isolation coupling module 120 as a low signal.
It should be noted that the second set value is greater than the first set value, and a difference between the second set value and the first set value is greater than a preset threshold, wherein the preset threshold is related to the resistances of the ninth resistor R9 and the first switch Q1 in the voltage adjustment module 130. Therefore, the voltage value corresponding to the reverse recovery voltage point is greater than the voltage value corresponding to the trigger action voltage point. Further, the trigger voltage point (i.e., the point corresponding to the operating voltage) is related to the resistance of the fourth resistor R4. The reverse recovery voltage point (i.e. the point corresponding to the hysteresis voltage) is related to the resistance of the ninth resistor R9 and the first switch Q1. When the first switching transistor Q1 is turned on, the hysteresis voltage decreases as the resistance of the ninth resistor R9 increases. When the resistance value of the ninth resistor R9 decreases, the hysteresis voltage increases.
In the hysteresis circuit 1000 according to any embodiment of the present invention, a hysteresis design for detecting an input voltage is implemented by setting a trigger action voltage point and a reverse recovery voltage point having a certain voltage difference, so that a state of the input voltage can be determined in time and accurately, a corresponding emergency lighting circuit can be further ensured to operate normally under a specified requirement, and reliability and safety of a product are improved.
In addition, in the hysteresis circuit 1000 according to any embodiment of the present invention, since the primary side of the optocoupler U1 is not grounded in common with the signal ground connected to the secondary side of the optocoupler U1 through the power ground connected to the voltage regulator U2 in the voltage detection module 110, the hysteresis circuit 1000 may be suitable for isolating a power supply, and a single chip microcomputer is not required to detect a sampling value, so that the hysteresis circuit 1000 according to the present invention has a wider application range.
Based on the same technical concept, an embodiment of the utility model also provides an emergency lighting circuit.
Referring to fig. 4, the emergency lighting circuit 2000 includes: a rectifier circuit 1100, a hysteresis circuit 1000, and a control circuit 1200.
Specifically, the rectifying circuit 1100 is configured to convert an input ac power into a dc power to provide the dc power to the hysteresis circuit 1000.
The hysteresis circuit is the hysteresis circuit 1000 according to any of the embodiments, and the specific structure and the operation principle thereof are as described above and are not described herein again.
The control circuit 1200 is configured to control whether an indicator lamp (not shown) or a relay (not shown) is operated according to the output signal Vbus _ c of the decoupling module 120 in the hysteresis circuit 1000.
When the voltage value corresponding to the output signal Vbus _ c is judged to be smaller than the preset threshold value, the state indicator lamp or the relay is controlled to work; and when the voltage value corresponding to the output signal Vbus _ c is judged to be greater than or equal to the preset threshold value, controlling the state indicator lamp or the relay to stop working. Wherein a status indicator light or relay is connected to the control circuit 1200. In this embodiment, when the output signal Vbus _ c is determined to be a low level signal, the status indicator lamp is controlled to be in an on state, or the relay is controlled to enter an operating state. And when the output signal Vbus _ c is judged to be a high level signal, the state indicator lamp is controlled to be in a turn-off state, or the relay is controlled to stop working.
As described in the background art, when the main power voltage of the lamp works at any voltage within the range of 60% -80% of the rated voltage, the state indicator lamp and the relay of the emergency lighting centralized power supply should not have the phenomenon of switching for many times, and if the phenomenon of switching for many times occurs, the main power voltage of the lamp has the problems of inevitable ripples and instability. Accordingly, the present invention provides an emergency lighting circuit 2000 that employs the hysteresis circuit 1000 described above for sensing and controlling the main power supply voltage (i.e., the input voltage) of the lamp.
During the process that the main power voltage is reduced to 60% to 80% of the rated voltage (i.e. the input voltage Vbus of the lamp is reduced from 100% of the rated voltage to 60% -80% of the rated voltage), the sampling voltage VA in the hysteresis circuit 1000 is correspondingly reduced along with the reduction of the input voltage, and when a trigger action voltage point is reached, the voltage regulator U2 is in a cut-off state, and the corresponding optocoupler U1 is in an isolation state, so that the output signal Vbus _ c of the isolating and coupling module 120 is a high-level signal. Since the output signal Vbus _ c of the isolation coupling module 120 is a high level signal (i.e., the output signal of the hysteresis circuit is a high level signal), the status indicator lamp connected to the control circuit 1200 in the emergency lighting circuit 2000 is in an off state, or the relay connected to the control circuit 1200 stops working, and accordingly, the lamp connected to the relay does not work, for example, the lamp is in an off state.
During the process that the main power voltage rises to be greater than 80% of the rated voltage (i.e. the input voltage Vbus of the lamp rises from 60% -80% of the rated voltage to be greater than 80% of the rated voltage), the sampled voltage in the hysteresis circuit 1000 rises correspondingly with the rise of the input voltage, and when the point of reverse recovery voltage is reached, the voltage regulator U2 is in a conducting state, and the corresponding optocoupler U1 is in a conducting state, so that the output signal Vbus _ c of the isolation coupling module 120 is a low-level signal. Since the output signal Vbus _ c of the isolation coupling module 120 is a low level signal (i.e., the output signal of the hysteresis circuit is a low level signal), the status indicator lamp connected to the control circuit 1200 in the emergency lighting circuit 2000 is in an on state, and at the same time, the relay connected to the control circuit 1200 starts to operate, and accordingly, the lamp connected to the relay enters an operating state, for example, the lamp is in an on state.
Since the trigger action voltage point and the reverse recovery voltage point with a certain voltage difference are set in the hysteresis circuit 1000, the state of the input voltage can be judged timely and accurately, and the corresponding emergency lighting circuit 2000 can be ensured to normally work under the regulation requirement (i.e., when the main power voltage is reduced to the range of 60% -80% of the rated voltage, the state indicator lamp or the relay does not work, and when the main power voltage is increased to be more than 80% of the rated voltage, the state indicator lamp or the relay enters the working state), so that the reliability and the safety of the lamp can be improved.
Based on the same technical concept, the embodiment of the utility model also provides the lighting equipment.
Referring to fig. 5, the lighting device 5000 includes the emergency lighting circuit 2000 described above. The lighting device 5000 may be an emergency lighting centralized power supply or a self-powered light fixture. In some embodiments, the emergency lighting centralized power supply is a non-centralized control type emergency lighting centralized power supply. In other embodiments, the automatic power type light fixture is a self-powered non-centralized control type light fixture. When the main power voltage of the equipment is reduced to 60% -80% of the rated voltage, the status indicator lamp or the relay does not work, and when the main power voltage of the equipment is increased to be more than 80% of the rated voltage, the status indicator lamp or the relay enters a working state, so that the safety and the reliability of the lighting equipment can be improved.
In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.
The hysteresis circuit, the emergency lighting circuit and the lighting device provided by the embodiment of the present invention are described in detail above, a specific example is applied in the present document to explain the principle and the implementation of the present invention, and the description of the above embodiment is only used to help understanding the technical scheme and the core idea of the present invention; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A hysteresis circuit, comprising:
the voltage detection module is used for receiving an input voltage, generating a sampling voltage according to the input voltage and detecting the sampling voltage;
the isolation coupling module is used for controlling an output signal of the isolation coupling module according to the sampling voltage;
the voltage adjusting module is used for adjusting the sampling voltage;
when the voltage detection module detects that the sampling voltage is smaller than a first set value, controlling an optical coupler in the isolation coupling module to be in an isolation state, so that an output signal of the isolation coupling module is a first level signal, and meanwhile, the voltage adjustment module starts to adjust the sampling voltage; when the voltage detection module detects that the sampling voltage is greater than a second set value, the optical coupler is controlled to be in a coupling state, so that an output signal of the isolation coupling module is a second level signal, meanwhile, the voltage adjustment module stops adjusting the sampling voltage, wherein the second set value is greater than the first set value, the difference value of the second set value and the sampling voltage is greater than a preset threshold value, and the first level signal is different from the second level signal.
2. The hysteresis circuit of claim 1, wherein the voltage detection module comprises: the voltage stabilizer comprises a first voltage-dividing resistor, a second voltage-dividing resistor, a first capacitor and a voltage stabilizer; a first end of the first voltage-dividing resistor receives the input voltage, a second end of the first voltage-dividing resistor is connected with a first end of the second voltage-dividing resistor to form a first node, the first voltage-dividing resistor and the second voltage-dividing resistor are used for dividing the input voltage to enable the voltage of the first node to be a sampling voltage, a first end of the second voltage-dividing resistor is electrically connected with a first end of the first capacitor and a first pin of the voltage stabilizer respectively, and a second end of the second voltage-dividing resistor is electrically connected with a second end of the first capacitor and a third pin of the voltage stabilizer respectively; the first end of the first capacitor is electrically connected with a first pin of the voltage stabilizer, and the second end of the first capacitor is electrically connected with a third pin of the voltage stabilizer; the second pin of the voltage stabilizer is connected with the isolation coupling module, the third pin of the voltage stabilizer is connected with a power ground, and the first pin of the voltage stabilizer is used for obtaining sampling voltage.
3. The hysteresis circuit of claim 2, wherein the voltage regulator is in an off state when the sampled voltage obtained at the first pin of the voltage regulator is less than a first set value; and when the sampling voltage obtained by the first pin of the voltage stabilizer is greater than a second set value, the voltage stabilizer is in a conducting state.
4. The hysteresis circuit of claim 1, wherein the isolation coupling module further comprises: a fifth resistor and a sixth resistor; a first end of the fifth resistor receives a first side power supply voltage, and a second end of the fifth resistor is electrically connected with a positive electrode of the light emitting diode on the primary side of the optical coupler; the first end of the sixth resistor is connected with a second side power supply voltage, and the second end of the sixth resistor is electrically connected with the collector electrode of the triode at the secondary side of the optical coupler; and the cathode of the light emitting diode at the primary side of the optical coupler is electrically connected with a second pin of the voltage stabilizer in the voltage detection module, and the emitter of the triode at the secondary side of the optical coupler is connected with a signal ground.
5. The hysteresis circuit of claim 1, wherein the voltage adjustment module comprises: the first voltage regulator tube, the seventh resistor, the eighth resistor, the ninth resistor and the first switch tube; a first end of the first voltage regulator tube is electrically connected with a first end of the seventh resistor, and a second end of the first voltage regulator tube is electrically connected with a second end of a fifth resistor in the isolation coupling module; the second end of the seventh resistor is electrically connected with the first end of the eighth resistor and the control end of the first switching tube respectively; the first end of the eighth resistor is electrically connected with the control end of the first switching tube, and the second end of the eighth resistor is electrically connected with the first end of the first switching tube; a first end of the ninth resistor is electrically connected with a first end of a second voltage-dividing resistor in the voltage detection module, and a second end of the ninth resistor is electrically connected with a second end of the first switching tube; the first end of the first switch tube is respectively connected with the second end of the second voltage-dividing resistor in the voltage detection module and the power ground.
6. The hysteresis circuit of claim 1, wherein the second voltage-dividing resistor in the voltage detection module and the ninth resistor in the voltage adjustment module are variable resistors.
7. The hysteresis circuit of claim 6, wherein the first set value is configurable to correlate with a resistance value of the second voltage-dividing resistor; the second set value may be configured to be associated with a resistance value of the ninth resistor.
8. The hysteresis circuit of claim 1, wherein a power ground connected to the primary side of the optocoupler by the voltage regulator in the voltage detection module is not common to a signal ground connected to the secondary side of the optocoupler.
9. An emergency lighting circuit, comprising:
the hysteresis circuit of any one of claims 1 to 8;
the rectifying circuit is used for converting input alternating current into direct current so as to provide the direct current to the hysteresis circuit;
and the control circuit is used for controlling whether the indicator light or the relay works or not according to the output signal of the isolation coupling module in the hysteresis circuit.
10. A lighting device characterized in that it comprises the emergency lighting circuit of claim 9.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113507772A (en) * | 2021-08-16 | 2021-10-15 | 欧普照明股份有限公司 | Hysteresis circuit, emergency lighting circuit and lighting equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113507772A (en) * | 2021-08-16 | 2021-10-15 | 欧普照明股份有限公司 | Hysteresis circuit, emergency lighting circuit and lighting equipment |
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