CN218298370U - Power failure detection circuit and AC-DC power module - Google Patents
Power failure detection circuit and AC-DC power module Download PDFInfo
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- CN218298370U CN218298370U CN202221949650.7U CN202221949650U CN218298370U CN 218298370 U CN218298370 U CN 218298370U CN 202221949650 U CN202221949650 U CN 202221949650U CN 218298370 U CN218298370 U CN 218298370U
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Abstract
The embodiment of the utility model relates to the technical field of power electronics, a fall electric detection circuitry and AC-DC power module is disclosed, fall electric detection circuitry includes first order comparison circuit, second level comparison circuit and controller, first order comparison circuit includes rectifier circuit and first comparator, rectifier circuit is connected with the live wire and the zero line of alternating current, the in-phase end and the output of rectifier circuit of first comparator are connected, the inverting terminal is used for the input reference voltage, the output is used for outputting square wave signal, second level comparison circuit input square wave signal converts to sawtooth wave signal and includes the second comparator, its inverting terminal is used for inputting sawtooth wave signal, the in-phase end is used for inputting reference voltage, the output is used for outputting the mark signal, the fall electric detection end configuration of controller is into input mark signal and judges according to mark signal whether the alternating current falls electric, the embodiment adopts two-stage comparison circuit to judge whether the alternating current falls electric, the circuit reliability is high, the delay is low, and simple structure, the cost is lower.
Description
Technical Field
The embodiment of the utility model provides a relate to power electronic technology field, in particular to fall electric detection circuitry and AC-DC power module.
Background
The AC-DC power supply module is very common in daily use as a power supply part of a system, however, because of the influence of uncertain factors such as lightning stroke and sudden change of power load of a power supply grid, the input voltage waveform can have the phenomena of wave shortage, distortion and even power failure. Especially for medical equipment, data processing centers, server systems and the like, when the input alternating current is in power failure, the power failure fault needs to be quickly detected, necessary protection is carried out on operating equipment, the normal work of electronic equipment is ensured, and the loss of lives and properties is reduced.
In realizing the embodiment of the utility model provides an in-process, the inventor finds that several common alternating current fall electric detection circuit exist following various problems at present: the scheme using the RC filtering energy storage circuit generally has long detection time and larger time delay; the scheme of using the optical coupler to carry out isolated sampling influences time precision due to the difference of the on-off threshold voltage of the optical coupler; the scheme of direct connection to alternating current high voltage detection is easy to malfunction when a power supply grid is not clean; the scheme of adopting alternating current differential input sampling, processing digital signals and realizing power failure detection in a software mode has high cost.
SUMMERY OF THE UTILITY MODEL
The embodiment of the application provides a power failure detection circuit and an AC-DC power module.
The embodiment of the utility model provides an aim at is realized through following technical scheme:
in order to solve the above technical problem, the first aspect of the present invention provides a power down detection circuit, including first order comparison circuit, second level comparison circuit and controller, wherein, first order comparison circuit includes at least: the input end of the first comparator is connected with the live wire and the zero line of alternating current, the in-phase end of the first comparator is connected with the output end of the rectifying circuit, the inverting end of the first comparator is used for inputting reference voltage, and the output end of the first comparator is used for outputting square wave signals; the second-stage comparison circuit inputs the square wave signal and converts the square wave signal into a sawtooth wave signal, and the second-stage comparison circuit at least comprises: the inverting end of the second comparator is used for inputting the sawtooth wave signal, the non-inverting end of the second comparator is used for inputting the reference voltage, and the output end of the second comparator is used for outputting the mark signal; and the power failure detection end of the controller is configured to input the mark signal and judge whether the alternating current is powered down or not according to the mark signal.
In some embodiments, the first stage comparison circuit further comprises: and the input end of the voltage division filter circuit is connected with a direct current voltage source, and the output end of the voltage division filter circuit is connected with the inverting end of the first comparator.
In some embodiments, the voltage dividing filter circuit includes: one end of the first resistor is connected with the direct-current voltage source, and the other end of the first resistor is connected with the inverting end of the first comparator; one end of the second resistor is connected with the other end of the first resistor, and the other end of the second resistor is grounded; and one end of the first capacitor is connected with the other end of the first resistor, and the other end of the first capacitor is grounded.
In some embodiments, the rectifier circuit comprises: a first diode, the anode of which is connected with the live wire of the alternating current; the anode of the second diode is connected with the zero line of the alternating current; a third resistor, one end of which is connected to the cathode of the first diode and the cathode of the second diode, and the other end of which is connected to the non-inverting terminal of the first comparator; and one end of the fourth resistor is connected with the other end of the third resistor, and the other end of the fourth resistor is grounded.
In some embodiments, the first stage comparison circuit further comprises: and one end of the protection circuit is connected with the in-phase end of the first comparator, and the other end of the protection circuit is grounded.
In some embodiments, the protection circuit includes: and the cathode of the first voltage-stabilizing tube is connected with the non-inverting end of the first comparator, and the anode of the first voltage-stabilizing tube is grounded.
In some embodiments, the second stage comparison circuit further comprises: and the input end of the attenuation filter circuit is connected with the output end of the first comparator, and the output end of the attenuation filter circuit is connected with the inverting end of the second comparator.
In some embodiments, the attenuation filter circuit comprises: one end of the fifth resistor is connected with the output end of the first comparator; a third diode having an anode connected to the other end of the fifth resistor and a cathode connected to the inverting terminal of the second comparator; a second capacitor, one end of which is connected to the cathode of the third diode and the inverting terminal of the second comparator, and the other end of which is grounded; and the eighth resistor is connected in parallel with two ends of the second capacitor.
In some embodiments, the second stage comparison circuit further comprises: and the input end of the voltage division feedback circuit is connected with a direct-current voltage source, the output end of the voltage division feedback circuit is connected with the in-phase end of the second comparator, and the feedback end of the voltage division feedback circuit is connected with the output end of the second comparator.
In some embodiments, the voltage division feedback circuit comprises: one end of the sixth resistor is connected with the direct-current voltage source, and the other end of the sixth resistor is connected with the in-phase end of the second comparator; one end of the seventh resistor is connected with the other end of the sixth resistor, and the other end of the seventh resistor is grounded; and the cathode of the fourth diode is connected with the non-inverting end of the second comparator, and the anode of the fourth diode is connected with the output end of the second comparator.
In some embodiments, the second stage comparison circuit further comprises: and the input end of the voltage division attenuation circuit is connected with the output end of the second comparator, and the output end of the voltage division attenuation circuit is connected with the power failure detection end of the controller and is used for modulating the mark signal and then outputting the mark signal.
In some embodiments, the voltage division attenuation circuit includes: one end of the ninth resistor is connected with the output end of the second comparator, and the other end of the ninth resistor is connected with the feedback end of the voltage division feedback circuit; the anode of the fifth diode is connected with the other end of the ninth resistor, and the cathode of the fifth diode is connected with the power failure detection end of the controller; a tenth resistor having one end connected to the cathode of the fifth diode and the other end grounded; and the third capacitor is connected in parallel with two ends of the tenth resistor.
In order to solve the above technical problem, in a second aspect, the embodiment of the present invention provides an AC-DC power module, which includes the power down detection circuit according to the first aspect.
Compared with the prior art, the beneficial effects of the utility model are that: be different from prior art's condition, the embodiment of the utility model provides a fall electric detection circuitry and AC-DC power module, this fall electric detection circuitry includes first order comparison circuit, second level comparison circuit and controller, wherein, first order comparison circuit is at least including rectifier circuit and the first comparator of connecting, rectifier circuit is connected with the live wire and the zero line of alternating current, the in-phase end and the output of rectifier circuit of first comparator are connected, the inverting terminal is used for the input reference voltage, the output is used for outputting square wave signal, second level comparison circuit input square wave signal converts into sawtooth wave signal, and second level comparison circuit includes the second comparator at least, its inverting terminal is used for inputing sawtooth wave signal, the in-phase end is used for inputing reference voltage, the output is used for exporting the mark signal, the fall electric detection terminal configuration of controller is the input mark signal and basis the signal is judged whether the alternating current falls electric, the embodiment adopts two-stage comparison circuit to judge whether the alternating current falls electric, the circuit reliability is high, the time delay is low, and simple structure, the cost is lower.
Drawings
The embodiments are illustrated by the figures of the accompanying drawings which correspond and are not meant to limit the embodiments, in which elements/blocks having the same reference number designation may be referred to by similar elements/blocks, unless otherwise indicated, and in which the drawings are not to scale.
Fig. 1 is a block diagram of a power down detection circuit according to an embodiment of the present invention;
fig. 2 is a block diagram of another power down detection circuit according to an embodiment of the present invention;
fig. 3 is a schematic circuit structure diagram of a power down detection circuit according to an embodiment of the present invention;
fig. 4 is a waveform diagram of level change of the power failure detection circuit in the case of transient wave loss distortion of the input ac power according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an AC-DC power module according to a second embodiment of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific embodiments. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that various changes and modifications can be made by one skilled in the art without departing from the spirit of the invention. All of which belong to the protection scope of the present invention.
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad application.
It should be noted that, if not conflicting, various features of the embodiments of the present invention may be combined with each other and all are within the scope of protection of the present application. In addition, although the functional blocks are divided in the device diagram, in some cases, the blocks may be divided differently from those in the device. Further, the terms "first," "second," "third," and the like, as used herein do not limit the order of data and execution, but merely distinguish between identical or similar items that have substantially the same function or effect. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Furthermore, the technical features mentioned in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
Specifically, the embodiments of the present invention will be further explained with reference to the drawings.
Example one
The embodiment of the utility model provides a fall electric detection circuitry, please refer to fig. 1, it shows the utility model provides a fall electric detection circuitry's block diagram, fall electric detection circuitry 10 and include first order comparison circuit 100, second level comparison circuit 200 and controller 300, wherein, first order comparison circuit 100 includes at least: the input end of the rectifying circuit 110 is connected with a live wire and a zero wire of Alternating Current (AC), the in-phase end of the first comparator U1A is connected with the output end of the rectifying circuit 110, the inverting end of the first comparator U is used for inputting reference voltage, and the output end of the first comparator U is used for outputting square wave signals; the second-stage comparison circuit 200 inputs the square wave signal and converts the square wave signal into a sawtooth wave signal, and the second-stage comparison circuit 200 at least includes: the inverting end of the second comparator U1B is used for inputting the sawtooth wave signal, the non-inverting end of the second comparator U1B is used for inputting the reference voltage, and the output end of the second comparator U1B is used for outputting the mark signal; the power-down detection terminal of the controller 300 is configured to input the flag signal and determine whether the ac power is powered down according to the flag signal. The sawtooth wave signal is a sawtooth wave signal which is charged quickly and discharged slowly.
The embodiment of the utility model provides an adopt two-stage comparison circuit to judge whether the alternating current falls the electricity, the circuit reliability is high, the immunity is strong, the time delay is low, and simple structure, cost are lower, can fall electric hold time according to the demand adjustment, and export to the controller through two-stage comparison circuit shielding alternating current near zero crossing behind the partial phase angle and fall electric judgement to avoid near the zero crossing because the amplitude is little the problem that the misjudgement takes place easily under noise interference's condition.
In some embodiments, please refer to fig. 2, which shows a block diagram of another power down detection circuit provided in an embodiment of the present invention, where the first-stage comparison circuit 100 further includes: the input end of the voltage division filter circuit 120 is connected to the dc voltage source VREF, and the output end thereof is connected to the inverting end of the first comparator U1A. After passing through the rectifying circuit 110 and the voltage-dividing filter circuit 120, the input ac voltage can be converted into an in-phase and low-amplitude steamed bread voltage, which is used as the input of the first comparator U1A.
Specifically, please refer to fig. 3, which shows a circuit structure of a power failure detection circuit provided by an embodiment of the present invention, the voltage dividing and filtering circuit 120 includes: a first resistor R1 having one end connected to the dc voltage source VREF and the other end connected to an inverting end of the first comparator U1A; one end of the second resistor R2 is connected with the other end of the first resistor R1, and the other end of the second resistor R2 is grounded; and one end of the first capacitor C1 is connected with the other end of the first resistor R1, and the other end is grounded. The first resistor R1 and the second resistor R2 are voltage division attenuation resistors, and voltage output by the direct-current voltage source VREF is subjected to voltage division and filtering through the first capacitor C1, the first resistor R1 and the second resistor R2 to obtain a reference voltage with constant voltage and then the reference voltage is input to the inverting terminal of the first comparator U1A.
Specifically, with continued reference to fig. 3, the rectifier circuit 110 includes: a first diode D1 having an anode connected to the live line of the alternating current; a second diode D2 having an anode connected to a zero line of the alternating current; a third resistor R3 having one end connected to the cathode of the first diode D1 and the cathode of the second diode D2 and the other end connected to the non-inverting terminal of the first comparator U1A; and one end of the fourth resistor R4 is connected to the other end of the third resistor R3, and the other end is grounded. The first diode D1 and the second diode D2 are rectifier diodes, and the third resistor R3 and the fourth resistor R4 are two divider resistors for input sampling.
In some embodiments, with continued reference to fig. 2, the first stage comparison circuit 100 further comprises: and a protection circuit 130 having one end connected to the non-inverting end of the first comparator U1A and the other end grounded. The protection circuit 130 is used for protecting the first comparator U1A from being damaged by the first comparator U1A in the case of an abnormal alternating current.
Specifically, with continued reference to fig. 3, the protection circuit 130 includes: a cathode of the first voltage-stabilizing tube Z1 is connected with the in-phase end of the first comparator U1A, and an anode of the first voltage-stabilizing tube Z1 is grounded; that is, the first regulator tube Z1 is connected in parallel to both ends of the fourth resistor R4. The first voltage-regulator tube Z1 is used for ensuring that the input pin of the first comparator U1A is not damaged due to overhigh voltage under the conditions of lightning stroke and large surge peak voltage.
The embodiment of the utility model provides a first order comparison circuit 100 during operation, input behind the attenuation filtering first comparator U1A's high level voltage is for supply voltage, low level voltage for being close zero volt's voltage, through first comparator U1A carries out the method of back, the square wave of output high level and/or low level with reference voltage. Specifically, when the voltage value input to the non-inverting terminal of the first comparator U1A is smaller than the reference voltage at the inverting terminal, the first comparator U1A outputs a low level, at this time, the voltage input to the non-inverting terminal of the first comparator U1A is a partial phase angle near the zero-crossing point of the alternating current, and other voltages having phase angles near the zero-crossing point are rectified by the rectifier circuit 110 and then compared with the reference voltage by the first comparator U1A, and then output a high level. The reference voltage can be adjusted by reasonably setting the ratio of the resistance values of the first resistor R1 and the second resistor R2 in the voltage division filter circuit 120, so that the first comparator U1A can determine the angle near the zero crossing of the sine wave as a low voltage, and prevent erroneous determination caused by interference and unstable sampling.
In some embodiments, with continued reference to fig. 2, the second stage comparator circuit 200 further comprises: an input end of the attenuation filter circuit 210 is connected to the output end of the first comparator U1A, and an output end thereof is connected to the inverting end of the second comparator U1B. The attenuation filter circuit 210 is configured to attenuate and filter the square wave signal output by the first comparator U1A into a sawtooth wave signal that is fast-charging and slow-discharging, and then use the sawtooth wave signal as an inverting terminal of the second comparator U1B for input.
Specifically, with continued reference to fig. 3, the attenuating filter circuit 210 includes: a fifth resistor R5, one end of which is connected to the output end of the first comparator U1A; a third diode D3 having an anode connected to the other end of the fifth resistor R5 and a cathode connected to the inverting terminal of the second comparator U1B; a second capacitor C2, one end of which is connected to the cathode of the third diode D3 and the inverting terminal of the second comparator U1B, and the other end of which is grounded; and an eighth resistor R8 connected in parallel to two ends of the second capacitor C2. Through the action of the second capacitor C2, the square wave signal can be adjusted to be a sawtooth wave signal which is charged quickly and discharged slowly, and through adjusting the capacitance value of the second capacitor C2 and the resistance value of the eighth resistor R8, the discharge time constant of the second capacitor C2 after the alternating current of an input system is powered down can be adjusted, so that the detection precision of the alternating current power down is adjusted and judged. The third diode D3 is used to prevent the second capacitor C2 from discharging through the fifth resistor R5 when the first comparator U1A outputs a low level due to the ac power being near the zero crossing or the ac power being lost.
In some embodiments, with continued reference to fig. 2, the second stage comparator circuit 200 further comprises: an input end of the voltage division feedback circuit 220 is connected to the dc voltage source, an output end thereof is connected to the non-inverting end of the second comparator U1B, and a feedback end thereof is connected to the output end of the second comparator U1B. Through the voltage division feedback circuit 220, the dc voltage source can input a stable reference voltage to the non-inverting terminal of the second comparator U1B, and on the other hand, can prevent the second comparator U1B from outputting high-low jitter.
Specifically, with continued reference to fig. 3, the voltage division feedback circuit 220 includes: a sixth resistor R6 having one end connected to the dc voltage source VREF and the other end connected to the non-inverting end of the second comparator U1B; a seventh resistor R7, one end of which is connected to the other end of the sixth resistor R6, and the other end of which is grounded; a fourth diode D4, a cathode of which is connected to the non-inverting terminal of the second comparator U1B, and an anode of which is connected to the output terminal of the second comparator U1B. The direct-current voltage source VREF obtains a stable reference voltage after voltage division through the sixth resistor R6 and the seventh resistor R7, and the stable reference voltage is used as an input reference set of the in-phase end of the second comparator U1B and is compared with a sawtooth wave voltage input to the inverting end of the second comparator U1B. The voltage values of the sixth resistor R6 and the seventh resistor R7 are adjusted, so that the minimum voltage value of the sawtooth wave output by the second capacitor C2 is kept larger than the reference voltage, and therefore, when the alternating current is normal, the output end of the second comparator U1B can keep outputting a low-level signal. And, the fourth diode D4 is a hysteresis diode, so that the second comparator U1B realizes a self-locking high-level signal function, and is used for preventing the output of the second-stage comparator U1B from repeatedly shaking high and low when the alternating current is powered off.
It should be noted that the dc voltage source VREF connected to the sixth resistor R6 and the dc voltage source VREF connected to the first resistor R1 may be the same dc voltage source, or may be two independent dc voltage sources; preferably, when the power failure detection circuits 10 are in the same power module, they share a dc voltage source, which may be specifically set according to actual needs.
In some embodiments, with continued reference to fig. 2, the second stage comparator circuit 200 further comprises: an input end of the voltage division attenuation circuit 230 is connected to an output end of the second comparator U1B, and an output end thereof is connected to the power-down detection end of the controller 300 and is configured to modulate the flag signal and then output the modulated flag signal. The level signal output by the second comparator U1B also needs to be divided, attenuated, and filtered by the voltage division and attenuation circuit 230 and then used as a flag signal for judging the power failure of the alternating current.
Specifically, with continued reference to fig. 3, the voltage division attenuation circuit 230 includes: a ninth resistor R9, one end of which is connected to the output end of the second comparator U1B, and the other end of which is connected to the feedback end of the voltage division feedback circuit 220, that is, the other end of which is connected to the anode of the fourth diode D4; a fifth diode D5, an anode of which is connected to the other end of the ninth resistor R9, and a cathode of which is connected to the power-down detection terminal of the controller 300; a tenth resistor R10 having one end connected to the cathode of the fifth diode D5 and the other end grounded; and a third capacitor C3 connected in parallel to two ends of the tenth resistor R10. The high-level signal output by the second comparator U1B is subjected to voltage division and attenuation by the ninth resistor R9 and the tenth resistor R10, and is subjected to shallow filtering by the third capacitor C3, and then is used as a flag signal for judging power failure of the alternating current.
The embodiment of the utility model provides a second level comparison circuit 200 during operation, the square wave signal of first comparator U1A output passes through the sawtooth wave of output behind the decay filter circuit 210 and input extremely second comparator U1B's inverting terminal, sawtooth wave's voltage value with input extremely the back is compared to the reference voltage of second comparator U1B's homophase end, outputs the low level when the alternating current is normal, outputs the high level when the alternating current falls the electricity. Specifically, after the ac power is turned off, the sawtooth voltage may continuously decrease, and when the sawtooth voltage value is decreased to be smaller than the reference voltage input at the non-inverting terminal of the second comparator U1B, the second comparator U1B outputs a high level. The time from the peak of the last sawtooth wave to the output of the second comparator U1B from low to high is obtained as the detection time of the power-off detection circuit.
Compared with the prior art, please refer to fig. 4, which shows a level change waveform diagram of the power failure detection circuit provided by the embodiment of the present invention under the condition that the input alternating current generates the transient wave loss distortion, as shown in fig. 4, after setting a scene that the transient wave loss distortion occurs, the detection of the plurality of voltage detection points of the power failure detection circuit provided by the embodiment of the present invention can be found out, and the power failure detection circuit provided by the embodiment of the present invention does not generate the false operation under the condition that the input alternating current generates the transient wave loss distortion, and has strong circuit reliability. Specifically, it is easy to find out by detecting the voltage Va at the non-inverting terminal of the first comparator U1A, the voltage Vb (square wave) at the output terminal of the first comparator U1A, the Vc (sawtooth wave) at the inverting terminal of the second comparator U1B, and the voltage Vd at the cathode terminal of the fifth diode D5 (i.e., the power failure detection terminal Vin _ drop of the controller 300), that the power failure detection circuit provided by the embodiment of the present invention can quickly return to the normal state for power failure detection after transient wave loss distortion such as surge, lightning stroke, jitter, etc., and the reliability of the circuit is strong.
Example two
The embodiment of the present invention provides an AC-DC power module, please refer to fig. 5, which shows the structure of an AC-DC power module provided by the embodiment of the present invention, the AC-DC power module 1 includes the power down detection circuit 10 as in the first embodiment.
The AC-DC power supply module 1 is a device, a module and a unit which can convert alternating current into direct current, and the AC-DC power supply module 1 can realize power failure detection of input alternating current by arranging the power failure detection circuit 10.
For the specific structure, connection relationship, operation principle, etc. of the power failure detection circuit 10, reference is made to the first embodiment, and fig. 1, fig. 2, and fig. 3, and details are not described here.
It should be noted that the controller 300 in the power failure detection circuit 10 may be a controller/control chip/control unit shared with other functions in the AC-DC power module 1, or may be a controller/control chip/control unit independently arranged in a module/circuit board of the power failure detection circuit 10, and may be specifically arranged according to actual needs. Furthermore, the controller 300 at least comprises a processor and a memory communicatively connected, wherein the memory stores instructions executable by the processor to enable the processor to execute the power failure detection method of the second embodiment; the memory, which is a non-volatile computer-readable storage medium, may be used to store non-volatile software programs, non-volatile computer-executable programs, and modules.
The embodiment of the utility model provides an in provide a fall electric detection circuitry and AC-DC power module, this fall electric detection circuitry includes first order comparison circuit, second level comparison circuit and controller, wherein, first order comparison circuit is at least including rectifier circuit and the first comparator of connection, rectifier circuit is connected with the live wire and the zero line of alternating current, the homophase end and the output of rectifier circuit of first comparator are connected, the inverting terminal is used for the input reference voltage, the output is used for exporting square wave signal, second level comparison circuit includes the second comparator at least, its inverting terminal is used for the sawtooth wave signal of quick-charging slow-release of input, the homophase end is used for importing reference voltage, the output is used for exporting the mark signal, the fall electric detection end configuration of controller is input mark signal and according to mark signal judges whether the alternating current falls electric, the embodiment adopts two-stage comparison circuit to judge whether the alternating current falls electric, circuit reliability is high, the delay is low, and simple structure, the cost is lower.
It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments can be combined, steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (13)
1. A power failure detection circuit is characterized by comprising a first-stage comparison circuit, a second-stage comparison circuit and a controller, wherein,
the first stage of comparison circuitry comprises at least:
a rectification circuit, the input end of which is connected with the live wire and the zero wire of the alternating current,
the non-inverting end of the first comparator is connected with the output end of the rectifying circuit, the inverting end of the first comparator is used for inputting reference voltage, and the output end of the first comparator is used for outputting square wave signals;
the second-stage comparison circuit inputs the square wave signal and converts the square wave signal into a sawtooth wave signal, and the second-stage comparison circuit at least comprises:
the inverting end of the second comparator is used for inputting the sawtooth wave signal, the non-inverting end of the second comparator is used for inputting the reference voltage, and the output end of the second comparator is used for outputting the mark signal;
and the power failure detection end of the controller is configured to input the mark signal and judge whether the alternating current is powered down or not according to the mark signal.
2. The power down detection circuit of claim 1, wherein the first stage comparison circuit further comprises:
and the input end of the voltage division filter circuit is connected with a direct current voltage source, and the output end of the voltage division filter circuit is connected with the inverting end of the first comparator.
3. The power-down detection circuit of claim 2, wherein the voltage-dividing filter circuit comprises:
one end of the first resistor is connected with the direct-current voltage source, and the other end of the first resistor is connected with the inverting end of the first comparator;
one end of the second resistor is connected with the other end of the first resistor, and the other end of the second resistor is grounded;
and one end of the first capacitor is connected with the other end of the first resistor, and the other end of the first capacitor is grounded.
4. The power down detection circuit according to claim 1, wherein the rectification circuit comprises:
a first diode having an anode connected to the hot line of the alternating current;
the anode of the second diode is connected with the zero line of the alternating current;
a third resistor, one end of which is connected to the cathode of the first diode and the cathode of the second diode, and the other end of which is connected to the non-inverting terminal of the first comparator;
and one end of the fourth resistor is connected with the other end of the third resistor, and the other end of the fourth resistor is grounded.
5. The power-down detection circuit of claim 2, wherein the first stage comparison circuit further comprises:
and one end of the protection circuit is connected with the in-phase end of the first comparator, and the other end of the protection circuit is grounded.
6. The power down detection circuit of claim 5, wherein the protection circuit comprises:
and the cathode of the first voltage-stabilizing tube is connected with the non-inverting end of the first comparator, and the anode of the first voltage-stabilizing tube is grounded.
7. The power loss detection circuit of any of claims 1-6, wherein the second stage comparison circuit further comprises:
and the input end of the attenuation filter circuit is connected with the output end of the first comparator, and the output end of the attenuation filter circuit is connected with the inverting end of the second comparator.
8. The power down detection circuit of claim 7, wherein the attenuating filter circuit comprises:
one end of the fifth resistor is connected with the output end of the first comparator;
a third diode having an anode connected to the other end of the fifth resistor and a cathode connected to the inverting terminal of the second comparator;
a second capacitor, one end of which is connected to the cathode of the third diode and the inverting terminal of the second comparator, and the other end of which is grounded;
and the eighth resistor is connected in parallel with two ends of the second capacitor.
9. The power-down detection circuit of claim 7, wherein the second stage comparison circuit further comprises:
and the input end of the voltage division feedback circuit is connected with a direct-current voltage source, the output end of the voltage division feedback circuit is connected with the in-phase end of the second comparator, and the feedback end of the voltage division feedback circuit is connected with the output end of the second comparator.
10. The power down detection circuit of claim 9, wherein the voltage division feedback circuit comprises:
one end of the sixth resistor is connected with the direct-current voltage source, and the other end of the sixth resistor is connected with the in-phase end of the second comparator;
one end of the seventh resistor is connected with the other end of the sixth resistor, and the other end of the seventh resistor is grounded;
and the cathode of the fourth diode is connected with the non-inverting end of the second comparator, and the anode of the fourth diode is connected with the output end of the second comparator.
11. The power down detection circuit of claim 9, wherein the second stage comparison circuit further comprises:
and the input end of the voltage division attenuation circuit is connected with the output end of the second comparator, and the output end of the voltage division attenuation circuit is connected with the power failure detection end of the controller and is used for modulating the sign signal and then outputting the sign signal.
12. The power down detection circuit of claim 11, wherein the voltage division attenuation circuit comprises:
one end of the ninth resistor is connected with the output end of the second comparator, and the other end of the ninth resistor is connected with the feedback end of the voltage division feedback circuit;
the anode of the fifth diode is connected with the other end of the ninth resistor, and the cathode of the fifth diode is connected with the power failure detection end of the controller;
a tenth resistor, one end of which is connected to the cathode of the fifth diode and the other end of which is grounded;
and the third capacitor is connected in parallel with two ends of the tenth resistor.
13. An AC-DC power supply module comprising the power down detection circuit of any of claims 1-12.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221949650.7U CN218298370U (en) | 2022-07-26 | 2022-07-26 | Power failure detection circuit and AC-DC power module |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221949650.7U CN218298370U (en) | 2022-07-26 | 2022-07-26 | Power failure detection circuit and AC-DC power module |
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| CN218298370U true CN218298370U (en) | 2023-01-13 |
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| CN202221949650.7U Active CN218298370U (en) | 2022-07-26 | 2022-07-26 | Power failure detection circuit and AC-DC power module |
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