CN218217095U - Power supply circuit - Google Patents

Abstract

The utility model relates to a power supply circuit. The power supply circuit includes: the start-stop control circuit is used for outputting a start signal when the working control signal of the electric equipment is greater than the start-stop reference signal; the driving power supply is used for converting the output voltage of the external power supply into a power supply voltage and outputting the power supply voltage to the electric equipment under the condition of receiving the starting signal; the overshoot starting suppression circuit is used for controlling the power supply voltage output by the driving power supply to gradually increase to a target working voltage according to the working voltage of the electric equipment; the target working voltage is a voltage matched with the working control signal of the electric equipment, and the target working voltage is smaller than or equal to the rated voltage of the electric equipment. When the power circuit is used as an LED driving power supply, the output positive overshoot of the power supply during starting can be inhibited, and the LED can normally emit light when being electrified, so that the service life of the LED is prolonged, and the use experience of a user is improved.

Description

Power supply circuit

Technical Field

The utility model relates to a power supply control technical field especially relates to a power supply circuit.

Background

When the electric equipment works, the power supply circuit supplies power to the electric equipment. At the moment of starting up the equipment, the problem that the output voltage or current amplitude of the power supply exceeds the rated range of the power supply can occur, so that the working state and the service life of the electric equipment are influenced to a certain extent.

SUMMERY OF THE UTILITY MODEL

Accordingly, it is desirable to provide a power circuit that prevents power-on output overshoot.

The embodiment of the application provides a power supply circuit, includes:

the starting and stopping control circuit is used for outputting a starting signal when the working control signal of the electric equipment is greater than the starting and stopping reference signal;

the first end of the driving power supply is used for being connected with an external power supply, the second end of the driving power supply is used for being connected with electric equipment, the third end of the driving power supply is connected with the third end of the start-stop control circuit, and the driving power supply is used for converting the output voltage of the external power supply into power supply voltage and outputting the power supply voltage to the electric equipment under the condition that the driving power supply receives a starting signal;

the first end of the over-regulation inhibiting starting circuit is used for accessing a working control signal of the electric equipment, the second end of the over-regulation inhibiting starting circuit is used for accessing the working voltage of the electric equipment, and the third end of the over-regulation inhibiting starting circuit is connected with the fourth end of the driving power supply;

the suppression overshoot starting circuit is used for controlling the power supply voltage output by the driving power supply to gradually rise to a target working voltage according to the working voltage of the electric equipment;

the target working voltage is a voltage matched with the working control signal of the electric equipment, and the target working voltage is smaller than or equal to the rated voltage of the electric equipment.

In one embodiment, the inhibit overshoot start circuit comprises:

the first end of the voltage loop circuit is used for accessing the working voltage of the electric equipment, and the second end of the voltage loop circuit is connected with the fourth end of the driving power supply; the voltage loop circuit is used for controlling the power supply voltage output by the driving power supply to gradually rise;

the first end of the current loop circuit is used for accessing a working control signal of the electric equipment, the second end of the current loop circuit is used for accessing a working voltage of the electric equipment, and the third end of the current loop circuit is connected with the fourth end of the driving power supply; the current loop circuit is used for controlling the power supply voltage output by the driving power supply to be matched with the working control signal of the electric equipment.

In one embodiment, the voltage loop circuit includes:

the first end of the delay charging circuit is used for accessing a start-stop reference signal, and the second end of the delay charging circuit is used for accessing the working voltage of the electric equipment;

and the first end of the first operational amplifier is connected with the third end of the delay charging circuit, the second end of the first operational amplifier is used for accessing the working voltage of the electric equipment, and the third end of the first operational amplifier is connected with the fourth end of the driving power supply.

In one embodiment, the delay charging circuit comprises:

the first end of the voltage division module is used for accessing the working voltage of the electric equipment, the second end of the voltage division module is connected with the second end of the first operational amplifier, and the third end of the voltage division module is grounded;

the first end of the energy storage element is connected with the third end of the voltage division module, and the second end of the energy storage element is connected with the first end of the first operational amplifier;

and the first end of the compensation module is used for accessing the start-stop reference signal, and the second end of the compensation module is connected with the first end of the first operational amplifier and used for providing a compensation potential for the first end of the first operational amplifier.

In one embodiment, the delay charging circuit further comprises:

the first pole of the switching tube is connected with the third end of the start-stop control circuit, the second pole of the switching tube is connected with the first end of the energy storage element, and the third pole of the switching tube is connected with the second end of the energy storage element;

the start-stop control circuit is also used for outputting a reset signal to the first pole of the switch tube to switch on the switch tube when the working control signal of the electric equipment is less than or equal to the start-stop reference signal.

In one embodiment, a current loop circuit comprises:

and the first end of the second operational amplifier is used for accessing a working control signal of the electric equipment, the second end of the second operational amplifier is used for accessing the working voltage of the electric equipment, and the third end of the second operational amplifier is connected with the fourth end of the driving power supply.

In one embodiment, the driving power supply includes:

the controller is connected with the third end of the start-stop control circuit at an enabling end and connected with the third end of the overshoot suppression starting circuit at a feedback end;

the first end of the power factor correction circuit is used for connecting an external power supply, and the second end of the power factor correction circuit is connected with the first output end of the controller;

and the first end of the resonant converter is connected with the third end of the power factor correction circuit, the second end of the resonant converter is connected with the second output end of the controller, and the third end of the resonant converter is used for connecting with the electric equipment.

In one embodiment, the start-stop control circuit comprises:

the first end of the third operational amplifier is used for accessing a working control signal of the electric equipment, the second end of the third operational amplifier is used for accessing a start-stop reference signal, and the third end of the third operational amplifier is connected with the first end of the overshoot suppression starting circuit;

and the first end of the first photoelectric coupler is connected with the third end of the third operational amplifier, and the second end of the first photoelectric coupler is connected with the third end of the driving power supply.

In one embodiment, the overshoot-suppression start-up circuit further comprises:

and the first end of the second photoelectric coupler is respectively connected with the third end of the voltage loop circuit and the third end of the current loop circuit, and the second end of the second photoelectric coupler is connected with the fourth end of the driving power supply.

In one embodiment, the power supply circuit further comprises:

and the auxiliary power supply is used for supplying power to the start-stop control circuit, the driving power supply and the over-regulation inhibition starting circuit.

The power supply circuit of the application has at least the following beneficial effects:

the power circuit comprises a start-stop control circuit, a driving power supply and an overshoot starting suppression circuit. And the start-stop control circuit outputs a start signal to start the driving power supply when the working control signal of the electric equipment is greater than the start-stop reference signal. The overshoot starting suppression circuit outputs a feedback signal to the fourth end of the driving power supply according to the actual working voltage of the electric equipment and the magnitude of the working control signal of the electric equipment, so that the power supply voltage output by the driving power supply is controlled to gradually rise to a target working voltage matched with the working control signal of the electric equipment, and the target working voltage is smaller than or equal to the rated voltage of the electric equipment. And then realize the power-on in the twinkling of an eye and restrain the output overshoot of power supply circuit, guarantee that consumer works in rated voltage scope, avoid its operating condition and life to receive the influence.

When the power circuit is used as an LED driving power supply, the output positive overshoot of the power supply during starting can be inhibited, and the LED can normally emit light when being electrified, so that the service life of the LED is prolonged, and the use experience of a user is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of an application scenario of a power circuit according to an embodiment;

FIG. 2 is a schematic diagram of a power circuit according to an embodiment;

FIG. 3 is a schematic diagram of an embodiment of an over-shoot suppressing start-up circuit;

FIG. 4 is a schematic diagram of a start-stop control circuit and an overshoot start-up suppression circuit according to an embodiment;

fig. 5 is a schematic structural diagram of a driving power supply according to an embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

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 application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first end may be referred to as a second end, and similarly, a second end may be referred to as a first end, without departing from the scope of the present application. Both the first end and the second end are ports, but they are not the same end.

It is to be understood that "connection" in the following embodiments is to be understood as "electrical connection", "communication connection", and the like if the connected circuits, modules, units, and the like have communication of electrical signals or data with each other.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," or "having," and the like, specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

In the present embodiment, an application scenario of the power supply circuit is shown in fig. 1. When the power circuit 1 in this embodiment is applied to LED driving, that is, when the electrical device 50 is an LED, the power circuit can be turned on in two ways. The first is to switch on the switch S1 for the first time or repeatedly to switch on the ac voltage from the external power source 10, at this time, the DIM +/-terminal is continuously connected to the powered device operation control signal VL, the ac voltage provides the LED with a power supply voltage matched with the powered device operation control signal VL through the power circuit provided in the embodiment of the present application, and the LED is powered on and operates at the target operating voltage desired by the user. The second method is to keep the switch S1 closed all the time, and then to control the power circuit to be turned on or turned off by first accessing or repeatedly adjusting the working control signal VL of the electric equipment through the +/-end of the DIM. When the power supply circuit is started to work, the power supply circuit provides power supply voltage matched with the current electric equipment work control signal VL for the LED. That is, the power circuit may continuously respond to changes in the powered device operation control signal VL to provide a matched supply voltage to the LEDs.

In this embodiment, a circuit configuration of the power supply circuit is shown in fig. 2. The power circuit includes a start-stop control circuit 20, a drive power supply 30, and an overshoot start suppression circuit 40.

The overshoot start suppression circuit 40 includes a voltage loop circuit 42 and a current loop circuit 44.

The start-stop control circuit 20 is configured to have a first end connected to the power consumption device operation control signal VL and a second end connected to the start-stop reference signal VREF, and output a start signal when the power consumption device operation control signal VL is greater than the start-stop reference signal VREF. The start-stop control circuit 20 may control the circuit module connected thereto to start based on the output of the start signal. In some embodiments, the start-stop control circuit 20 may also output a reset signal, which is used to drive the associated circuit module to reset or stop operating.

The first end of the driving power supply 30 is used for connecting the external power supply 10, the second end is used for connecting the electric device 50, the third end is connected with the third end of the start-stop control circuit 20, and the driving power supply 30 is used for converting the output voltage of the external power supply 10 into a power supply voltage and outputting the power supply voltage to the electric device 50 under the condition of receiving the starting signal, so that the adaptive power supply voltage is provided for the electric device 50. For example, 220V ac power from the external power source 10 may be converted to a lower dc power (e.g., 24V dc voltage) to match the dc power requirements of the powered device 50.

A first end of the overshoot start-up suppression circuit 40 is used for accessing the electrical equipment working control signal VL, a second end is used for accessing the working voltage of the electrical equipment 50, and a third end is connected with a fourth end of the driving power supply 30; the overshoot start suppression circuit 40 is configured to control the power supply voltage output by the driving power supply 30 to gradually increase to a target operating voltage according to the operating voltage of the electric device 50; the target operating voltage is a voltage matched with the electric device operation control signal VL, and is less than or equal to the rated voltage of the electric device 50. The voltage matched to the electric device operation control signal VL is a voltage that can drive the electric device 50 to operate at an operation parameter desired by a user. For example, when the electric device 50 is an LED, the user expects the LED to operate at a brightness, and in this case, the matched voltage is a voltage that enables the LED to operate at a brightness.

Specifically, based on the above circuit structure, the power supply circuit provided in the embodiment of the present application first compares the power consumption device operation control signal VL with the start-stop reference signal VREF by the start-stop control circuit 20, and outputs the start signal to the driving power supply 30 if the power consumption device operation control signal VL is greater than the start-stop reference signal VREF. The driving power supply 30 starts to work, and meanwhile, the suppression overshoot starting circuit 40 outputs a feedback signal to the fourth end of the driving power supply 30 according to the actual working voltage of the electric equipment 50 and the working control signal VL of the electric equipment, so that the power supply voltage output by the driving power supply 30 is controlled to gradually rise to the target working voltage, the power supply circuit can be suppressed from outputting overshoot at the moment of starting, the electric equipment 50 is guaranteed to work within the rated voltage range, and the working state and the service life of the electric equipment are prevented from being influenced.

In one embodiment, shown in FIG. 3, the inhibit overshoot start circuit 40 includes a voltage loop circuit 42 and a current loop circuit 44.

The first end of the voltage loop circuit 42 is used for accessing the working voltage of the electric equipment 50, and the second end is connected to the fourth end of the driving power supply 30; the voltage loop circuit 42 is used to control the supply voltage output by the driving power supply 30 to gradually rise. The voltage loop circuit 42 can control the power supply voltage output by the driving power supply 30 to slowly rise according to the change condition of the working voltage of the electric equipment 50, and through the control process, the forward overshoot caused by the overlarge power supply voltage which is connected to the electric equipment 50 by the driving power supply 30 at the moment of starting can be prevented.

A first end of the current loop circuit 44 is configured to access the electrical device operation control signal VL, a second end is configured to access the operating voltage of the electrical device 50, and a third end is connected to the fourth end of the driving power supply 30; the current loop circuit 44 is used to control the power supply voltage output by the driving power supply 30 to match the power consumption device operation control signal VL. The operating voltage of the electric equipment 50 connected to the voltage loop circuit 42 and the current loop circuit 44 may be received from different points of the electric equipment 50. May be voltage signals of different magnitudes, but all of which are indicative of the operation of the powered device 50. For example, the current loop circuit 44 may be connected to the negative electrode of the electric device 50 through a sampling resistor, and based on the magnitude of the resistance value of the constant sampling resistor and the obtained voltage, the operating current level of the electric device 50 may be known, and then the adjustment of the driving power supply 30 may be performed.

Specifically, the voltage loop circuit 42 may feed back the operating voltage of the electric device 50 connected to the second terminal to the fourth terminal of the driving power supply 30 by using the delay charging circuit 422 or the like, so as to reduce the rising speed of the power supply voltage output by the driving power supply 30, and prevent the driving power supply 30 from outputting an excessive voltage at the moment of powering on and powering off. Meanwhile, the current loop circuit 44 feeds back a comparison result of the first terminal and the second terminal access signal to the fourth terminal of the driving power supply 30 through an operational amplifier or the like, controls the driving power supply 30 to output a supply voltage matched with the power consumption device operation control signal VL, and uses the power consumption device 50 to stably operate at the target operation voltage. By adopting the way of matching the voltage loop circuit 42 and the current loop circuit 44, the voltage loop circuit 42 is rapidly closed at the moment of power-on, thereby avoiding the positive overshoot of the output voltage at the moment of power-on of the driving power supply 30, and meanwhile, the current loop circuit 44 controls the driving power supply 30 to output the target working voltage based on the collection of the working voltage of the electric equipment 50.

In one embodiment, as shown in FIG. 4, the voltage loop circuit 42 includes a delay charging circuit 422 and a first operational amplifier.

The first end of the delay charging circuit 422 is used for accessing the start-stop reference signal VREF, and the second end is used for accessing the working voltage of the electric equipment 50; the first end of the first operational amplifier is connected to the third end of the delay charging circuit 422, the second end is used for accessing the working voltage of the electric equipment 50, and the third end is connected to the fourth end of the driving power supply 30.

Specifically, when the delay charging circuit 422 receives the operating voltage of the electric device 50, the delay charging circuit 422 may include an energy storage element, and based on the delay function, the voltage rising speed of the first end of the first operational amplifier may be much smaller than the voltage rising speed of the second end of the first operational amplifier, so as to cause the potential at the third end of the first operational amplifier to change, and the change result is fed back to the fourth end of the driving power supply 30. The driving power supply 30 gradually increases the power supply voltage output to the electric equipment 50 based on the potential change result until the first terminal and the second terminal of the first operational amplifier are equal, the potential at the third terminal of the first operational amplifier is not changed, the voltage loop circuit 42 reaches a steady state, and the working voltage of the electric equipment 50 is stabilized at a fixed value. Therefore, the positive overshoot of the output voltage caused by the light load of the driving power supply 30 at the moment of starting up and electrifying can be avoided.

In one embodiment, as shown in fig. 4, the delay charging circuit 422 includes a voltage dividing module, an energy storage element and a compensation module.

The first end of the voltage dividing module is used for accessing the working voltage of the electric equipment 50, the second end of the voltage dividing module is connected with the second end of the first operational amplifier, and the third end of the voltage dividing module is grounded. The voltage division module can be realized by at least one voltage division resistor. Or other voltage divider devices, and are not exhaustive. Specifically, the voltage division may be performed using resistors R6, R7, and R8 as shown in fig. 4.

The first end of the energy storage element is connected with the third end of the voltage division module, and the second end of the energy storage element is connected with the first end of the first operational amplifier. The energy storage element is a device capable of storing the electric energy provided by the voltage dividing module, and may include, for example, a capacitor device or other devices. Specifically, the capacitor C3 shown in fig. 4 may be used first, and the power circuit is small.

The first end of the compensation module is used for accessing the start-stop reference signal VREF, and the second end of the compensation module is connected with the first end of the first operational amplifier and used for providing compensation potential for the first end of the first operational amplifier. The compensation potential is a potential that makes the potentials connected to the first terminal and the second terminal of the first operational amplifier the same when the voltage loop circuit 42 reaches the closed loop steady state. And the compensation module refers to a voltage generation circuit that can provide the potential of this nature. The compensation module is connected with a start-stop reference signal VREF, and shares the same reference signal with the start-stop control circuit 20, so that the circuit structure can be simplified, the size of a power circuit is reduced, and the cost is reduced. Specifically, the start-stop reference signal VREF and the resistor R8 shown in fig. 4 may be used to provide a compensation potential for the second terminal of the first operational amplifier.

Specifically, the voltage dividing module divides the operating voltage from the power consumption device 50, converts the operating voltage into a voltage suitable for being input to the first operational amplifier, and inputs the voltage to the second end of the first operational amplifier and the energy storage element respectively. After the energy storage element receives the output voltage of the voltage dividing module, the voltage rising speed of the first end of the first operational amplifier is reduced through the energy storage process, so that the potential difference between the first end and the second end of the first operational amplifier is caused, and the potential difference changes along with the time change, and the potential of the third end of the first operational amplifier is caused to change. Based on the voltage dividing module, the magnitudes of the potentials connected to the first end and the second end of the first operational amplifier may not be consistent, so that the first operational amplifier may not control the power supply voltage output by the driving power supply 30 to reach the target working voltage, and based on this, the compensation module further provides the compensation potential for the first end of the first operational amplifier, so that when the voltage loop circuit 42 reaches the closed-loop steady state, the voltages of the first end and the second end of the first operational amplifier are equal, so that the driving power supply 30 may provide the target working voltage.

In one embodiment, as shown in fig. 4, the delay charging circuit 422 further includes a switch tube.

A first pole of the switching tube is connected with a third end of the start-stop control circuit 20, a second pole of the switching tube is connected with a first end of the energy storage element, and a third pole of the switching tube is connected with a second end of the energy storage element; the start-stop control circuit 20 is further configured to output a reset signal to the first pole of the switching tube to turn on the switching tube when the power consumption device operation control signal VL is less than or equal to the start-stop reference signal VREF. It should be understood that, if a voltage dividing resistor and other devices are connected in series between the power consumption device operation control signal VL and the first end of the start-stop control circuit 20, so that the electrical signal connected to the first end of the start-stop control circuit 20 is smaller than the power consumption device operation control signal VL, it should be understood by those skilled in the art that, in this case, the electrical signal actually connected to the first end is smaller than or equal to the start-stop reference signal VREF, and the reset signal is output. Similarly, in the above embodiments, the process of outputting the start signal when the power consumption device operation control signal VL is greater than the start/stop reference signal VREF may also be understood with reference to the explanation herein.

Specifically, after one power-up process, the energy storage element in the delayed charging circuit 422 may naturally discharge the stored energy for a period of time to fully operate when the power-up process is performed again. Otherwise, the electric energy stored in the energy storage element is not discharged completely, so that the electric potential of the first end of the first operational amplifier is rapidly increased to be the same as that of the second end, the time for the voltage loop circuit 42 to be closed in a stable state is shortened, and the over-regulation inhibiting effect at the moment of starting is influenced. When the power-driven equipment work control signal VL is less than or equal to the start-stop reference signal VREF, the start-stop control circuit 20 outputs a reset signal to the switch tube to enable the switch tube to be conducted, and based on a discharge circuit formed by the switch tube and the energy storage element, electric energy in the energy storage element is rapidly released. Through the mode, when the power-consumption equipment work control signal VL is adjusted to be turned on and turned off repeatedly, the energy storage element can be discharged and reset at first, then based on the charging effect of the energy storage element, the delay charging circuit 422 controls the voltage rise of the first end of the first operational amplifier repeatedly, and the overshoot of the power supply output voltage is effectively inhibited.

In one embodiment, as shown in FIG. 4, the current loop circuit 44 includes a second operational amplifier.

The first end of the second operational amplifier is used for accessing the working control signal VL of the electric device, the second end is used for accessing the working voltage of the electric device 50, and the third end is connected to the fourth end of the driving power supply 30.

Specifically, the second operational amplifier compares the signals of the first terminal and the second terminal, changes the potential of the third terminal of the first operational amplifier according to the comparison result, and feeds back the change result to the fourth terminal of the driving power supply 30. The drive power supply 30 converts the output voltage of the external power supply 10 into a supply voltage matching the electric-device operation control signal VL based on the potential change result, and supplies the same to the electric device 50. Until the voltage signals of the first end and the second end of the second operational amplifier are equal, the potential of the third end of the second operational amplifier does not change any more, the current loop circuit 44 reaches a steady state, and the consumer device 50 stably operates at the target operating voltage.

In one embodiment, as shown in fig. 5, the driving power supply 30 includes: a controller 32, a power factor correction circuit 34, and a resonant converter 36.

The enable terminal of the controller 32 is connected to the third terminal of the start-stop control circuit 20, and the feedback terminal is connected to the third terminal of the overshoot-suppression starting circuit 40.

A first terminal of the Power Factor Correction circuit 34 (PFC) is connected to the external Power source 10, and a second terminal is connected to a first output terminal of the controller 32. The power factor correction circuit 34 is a circuit for suppressing distortion of a current waveform and increasing a power factor. By controlling the operating frequency of the switching tube, the power factor correction circuit 34 can be controlled to output different waveform currents.

The resonant converter 36 (LLC) has a first terminal connected to the third terminal of the power factor correction circuit 34, a second terminal connected to the second output terminal of the controller 32, and a third terminal for connecting the consumer 50. The resonant converter 36 generates high frequency resonance when an ac square wave voltage or current is applied across the resonant converter 36, and the resonant voltage or current is rectified and filtered and converted into a dc voltage or current by the resonant converter 36. Based on the cooperation of the PFC and LLC circuits, pulse control signals with different duty ratios can be input through the controller 32 to control the operating states of the switching tubes in the PFC and LLC circuits, so that the switching tubes can convert the ac voltage input by the external power supply 10 into a dc voltage of a specific magnitude and provide the dc voltage as a supply voltage to the electrical equipment 50.

Specifically, after the enable terminal of the controller 32 receives the start signal from the start-stop control circuit 20, according to the magnitude of the feedback signal received by the feedback terminal from the overshoot-suppression start circuit 40, a first pulse driving signal is output to the power factor correction circuit 34, and a second pulse driving signal is output to the resonant converter 36, and the on/off of the switching tubes in the power factor correction circuit 34 and the resonant converter 36 are respectively controlled based on the pulse control signal, wherein the magnitude of the duty ratio of the pulse driving signal is determined based on the magnitude of the feedback signal received by the overshoot-suppression start circuit 40, and the final purpose is to convert the ac voltage input by the external power supply 10 into the target operating voltage, and use the electrical device 50 to operate in the operating state desired by the user.

In one embodiment, as shown in fig. 4, the start-stop control circuit 20 includes a third operational amplifier and a first photo-coupler.

The first end of the third operational amplifier is used for accessing an electric equipment working control signal VL, the second end of the third operational amplifier is used for accessing a start-stop reference signal VREF, and the third end of the third operational amplifier is connected with the first end of the suppression overshoot starting circuit 40; the first end of the first photoelectric coupler is connected with the third end of the third operational amplifier, and the second end is connected with the third end of the driving power supply 30. The first end of the first photoelectric coupler is connected with the third end of the third operational amplifier, and the light emitting condition of the light emitter is determined by the output signal of the third end of the third operational amplifier. The second end of the photoelectric coupler is connected with the third end of the driving power supply 30, that is, the size of an electric signal connected to the third end of the driving power supply 30 changes along with the conduction degree of the light receiver under the action of light projected by the light emitter matched with the light receiver, so that feedback is realized.

Specifically, when the power consumption device operation control signal VL accessed by the third operational amplifier is less than or equal to the start-stop reference signal VREF, the reset signal acts on the enable terminal of the controller 32, the controller 32 stops operating, at this time, the entire driving power supply 30 is in a shutdown state, the third terminal of the third operational amplifier outputs the reset signal to turn on the switching tube in the overshoot start-up suppression circuit 40, and releases the electric energy in the energy storage element, so that the effective control of the output voltage when the power consumption device operation control signal VL is repeatedly turned on and off is realized. When the power supply is started next time, that is, the power consumption equipment working control signal VL connected to the third operational amplifier is greater than the start-stop reference signal VREF, the third end of the third operational amplifier outputs a start signal to the first photoelectric coupler, the third end of the third operational amplifier is subjected to photoelectric isolation conversion by the first photoelectric coupler and then is input to the enable end of the controller 32, the controller 32 works, and the feedback signal at the input end of the feedback end controls the working states of the power factor correction circuit 34 and the resonant converter 36 so as to provide a target working voltage to the power consumption equipment 50.

In one embodiment, as shown in fig. 4, the overshoot start-up suppression circuit 40 further comprises a second photo coupler.

A first end of the second photocoupler is connected to the third end of the voltage loop circuit 42 and the third end of the current loop circuit 44, and a second end of the second photocoupler is connected to the fourth end of the driving power supply 30.

Specifically, when the voltage loop circuit 42 and the current loop circuit 44 operate, the potential at the first end of the second photocoupler changes, and the potential change result is subjected to photoelectric isolation conversion by the second photocoupler and then is input to the feedback end of the controller 32. The controller 32 controls the power factor correction circuit 34 and the resonant converter 36 to convert the output voltage of the external power supply 10 into the target operating voltage.

In one embodiment, as shown in fig. 4 and 5, the power circuit further includes an auxiliary power supply. The auxiliary power supply is used for supplying power to the start-stop control circuit 20, the driving power supply 30 and the over-regulation inhibiting starting circuit 40.

Specifically, the auxiliary power supply independently supplies power to the first operational amplifier and the second operational amplifier in the start-stop control circuit 20 and the third operational amplifier in the start-stop control circuit 40, and the controller 32, the power factor correction circuit 34 and the resonant converter 36 in the driving power supply 30, so that each module of the power supply circuit normally works, and the output overshoot of the power supply circuit is suppressed at the moment of starting.

In one embodiment, the input of the auxiliary power supply may also be used for connecting the external power supply 10, in order to save the volume of the power supply circuit. At this time, the auxiliary power supply may include various types of voltage conversion chips, and provide a working voltage adapted to the power supply requirement of each circuit module based on the power supply requirement of each circuit module. Of course, the auxiliary power source may be a battery or the like.

In order to better help the skilled in the art to understand the implementation of the power supply circuit provided in the present application, the specific circuit structures of the start-stop control circuit 20, the overshoot suppression start circuit 40, and the driving power supply 30 shown in fig. 4 and 5 are taken as examples to illustrate the operation process, but the actual protection scope of the present application is not limited.

As shown in fig. 4, the start-stop control circuit 20 receives the electrical device operation control signal VL from the ADJ end, and first, the electrical device operation control signal VL is received by the front end network formed by R11, C4, R1, C6, and R3, and after voltage division filtering, the electrical device operation control signal VL reaches the ADJ1 end, and is input to the negative input end of the third operational amplifier a, and the start-stop reference signal VREF is input to the positive input end of the third operational amplifier a. On the basis of the power-on and power-off voltage requirement of the electric equipment 50, the start-up and shut-down reference signal VREF and the parameters of the front-end network are set so as to determine that when the negative input voltage of the third operational amplifier a reaches the power-on and power-off voltage threshold, the third operational amplifier a outputs a start signal to trigger the driving power supply 30 to be powered on and operated, and meanwhile, when the negative input voltage is lower than the power-on and power-off voltage threshold, the third operational amplifier a outputs a reset signal to achieve power-off.

When the first mode shown in FIG. 1 is used for power-on, the switch S1 is closed and the power-on operation control signal VL is accessed at DIM +/-terminal, and the voltage at the ADJ1 terminal (point D) is greater than the power-on/off voltage threshold. The operational amplifier A outputs a low level (point E), wherein R2 plays a role in current limiting. At this time, no current passes through the light emitter U2A of the second photocoupler, the light receiver U2B of the second photocoupler at the enable terminal (EN) of the controller 32 (a main control chip as shown in fig. 5 may be used) is not turned on, the high potential at the enable terminal of the main control chip is enabled normally, and the second photocoupler operates normally after receiving VCC from the auxiliary power supply. Optionally, when the electric device 50 is an LED, a dimming chip may be connected between the DIM +/-terminal and the ADJ terminal in series, so as to convert the electric device operation control signal VL into a dimming signal. In this case, the comparison with the electric device operation control signal VL in the above embodiment is understood as a comparison with the dimming signal here.

As shown in fig. 5, the driving power supply 30 receives an ac voltage from the external power supply 10, and the ac voltage is converted into a dc voltage through the power factor correction circuit 34 and the resonant converter 36, and then input to the electric devices 50, that is, the (LED +, LED-) terminals. The controller 32 outputs two paths of driving output signals respectively to drive the on-off frequency of the switching tubes Q1 to Q3, and controls the magnitude of the dc voltage output by the driving power supply 30.

As shown in fig. 4, the overshoot start suppression circuit 40 takes the voltages of the LED + terminal and the CS terminal from the output terminal of the driving power supply 30 and connects them to the voltage loop circuit 42 and the current loop circuit 44, respectively. The voltage loop circuit 42 and the current loop circuit 44 jointly control the magnitude of the current in the light emitter U3A of the first photocoupler, i.e., control the on state of the light receiver U3B of the feedback terminal (FB) of the main control chip in fig. 5, to adjust the duty ratio of the pulse driving signal output by the controller 32, thereby forming two closed loop control loops.

The voltage loop circuit 42 is connected to the operating voltage of the electric device 50 from the LED + terminal, and outputs the operating voltage to the first terminal (negative input terminal, point a) of the first operational amplifier B after being divided by R6, R7, and R10, and the energy storage element C3 delays the voltage rise of the second terminal (positive input terminal, point C) of the first operational amplifier B through the energy storage process. Based on the potential difference between the positive and negative input terminals, the voltage at the third terminal (point B) of the first operational amplifier B is pulled low, and in combination with the action of the diode D1 and the voltage VCC provided by the auxiliary power supply, the current in the light emitter U3A of the first photocoupler is increased and fed back to the feedback terminal (FB) of the controller 32 through the light receiver U3B, so that the rising speed of the power supply voltage output by the driving power supply 30 is reduced. After the energy storage of the energy storage element C3 is completed, in combination with the compensation potential provided by the compensation module R8 to the negative input end (point a) of the first operational amplifier B, the potential difference between the positive input end and the negative input end of the first operational amplifier B gradually decreases and tends to 0, so that the voltage at the output end gradually increases and tends to 0, and thus the conduction states of U3A and U3B tend to be stable, and the supply voltage output by the driving power supply 30 is stable.

The positive input terminal (first terminal) of the second operational amplifier U2 in the current loop circuit 44 is connected to the voltage of the electric device operation control signal VL at the ADJ1 terminal, and the negative input terminal (second terminal) is connected to the voltage of the electric device 50 from the CS terminal. Based on the variation of the input voltage difference value at the positive and negative input terminals, the voltage at the output terminal (the third terminal) of the second operational amplifier U2 will vary, and based on the variation, the controller 32 will continuously adjust the duty ratio of the pulse driving signal outputted to the power factor correction circuit 34 and the resonant converter 36, so as to vary the power supply voltage outputted by the driving power supply 30. In the current loop closed-loop control, the voltage at the CS end is gradually equal to the voltage at the AJD1 end, so that the voltage at the output end gradually tends to 0, the conduction states of U3A and U3B tend to be stable, and the supply voltage output by the driving power supply 30 is matched with the target working voltage represented by the electric device working control signal VL.

When the power-on is carried out by using the second mode shown in fig. 1, the DIM +/-terminal is connected to the power-on operation control signal VL for the first time or repeatedly and slowly adjusts the power-on operation control signal VL, and the switch S1 is always closed. When the voltage of the end (point D) of the ADJ1 is lower than the threshold of the on-off voltage, the third operational amplifier A outputs high level, and the triode Q1 is conducted through R9, so that the electric energy stored in the energy storage element C3 is released. The voltage loop circuit 42 is reset, so that the energy storage element C3 can store energy each time the power supply is turned on by adjusting the working control signal VL of the electric device, the voltage rise of the positive input end of the first operational amplifier B is delayed, and the working process of the first photoelectric coupler is repeated, so that the rising speed of the power supply voltage output by the driving power supply 30 is reduced, and the purpose of controlling the output overshoot is achieved. Meanwhile, the high level output by the third operational amplifier a also enables the light emitter U2A of the second photoelectric coupler to work, and the light receiver U2B of the second photoelectric coupler at the enable End (EN) of the chip is conducted and grounded, so that the chip is in a shutdown state, and the power circuit is shut down. When the power consumption equipment work control signal VL is larger than the power on/off voltage threshold, the operational amplifier A outputs a low level, the chip works normally, and the power circuit can work, so that the power supply voltage output by the driving power supply 30 rises slowly and is matched with the target work voltage represented by the power consumption equipment work control signal VL, and the output overshoot of the power circuit is inhibited.

Those skilled in the art will appreciate that: in this example, U1 and U2 may be a single operational amplifier, a dual operational amplifier, or a functional device such as a comparator, and the specific type is not limited. In addition, in the above embodiments, the positions and the number of the resistors for limiting current and dividing voltage are not limited by the description of the above embodiments, and those skilled in the art can adaptively select the position and the number based on the actual power supply requirement of the electrical equipment. The switching tube in the embodiment of the application can adopt a transistor, a field effect tube or a composite switching tube and the like. The type and model of the switch tube is not limited by the description of the embodiment. The generation manner of the start signal may be implemented by other alternative schemes besides the implementation manner described in the above embodiments. The type of the controller 32 is not limited to the above embodiment, and an integrated chip may be used to reduce the size of the power circuit, or a non-integrated circuit composed of logic devices may be used. The circuit structures of the power factor correction circuit 34 and the resonance converter 36 are not limited, and any structures that perform the same functions as described above are all within the protection scope of the embodiments of the present application. The correlation form between the DIM +/-terminal and the ADJ terminal is not limited, and only the signals at the two terminals are in a direct proportion relation.

In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic depictions of the above terms do not necessarily refer to the same embodiment or example.

All possible combinations of the technical features in the above embodiments may not be described for the sake of brevity, but should be considered as being within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above embodiments only represent several embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which all fall within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A power supply circuit, comprising:

the starting and stopping control circuit is used for outputting a starting signal when the working control signal of the electric equipment is greater than the starting and stopping reference signal;

the first end of the driving power supply is used for being connected with an external power supply, the second end of the driving power supply is used for being connected with electric equipment, the third end of the driving power supply is connected with the third end of the start-stop control circuit, and the driving power supply is used for converting the output voltage of the external power supply into power supply voltage and outputting the power supply voltage to the electric equipment under the condition that the starting signal is received;

the first end of the over-regulation inhibiting starting circuit is used for accessing the working control signal of the electric equipment, the second end of the over-regulation inhibiting starting circuit is used for accessing the working voltage of the electric equipment, and the third end of the over-regulation inhibiting starting circuit is connected with the fourth end of the driving power supply;

the over-regulation inhibiting starting circuit is used for controlling the power supply voltage output by the driving power supply to gradually rise to a target working voltage according to the working voltage of the electric equipment;

the target working voltage is a voltage matched with the working control signal of the electric equipment, and the target working voltage is smaller than or equal to the rated voltage of the electric equipment.

2. The power supply circuit of claim 1, wherein the inhibit overshoot start circuit comprises:

the first end of the voltage loop circuit is used for accessing the working voltage of the electric equipment, and the second end of the voltage loop circuit is connected with the fourth end of the driving power supply; the voltage loop circuit is used for controlling the power supply voltage output by the driving power supply to gradually rise;

the first end of the current loop circuit is used for accessing the working control signal of the electric equipment, the second end of the current loop circuit is used for accessing the working voltage of the electric equipment, and the third end of the current loop circuit is connected with the fourth end of the driving power supply; and the current loop circuit is used for controlling the power supply voltage output by the driving power supply to be matched with the working control signal of the electric equipment.

3. The power supply circuit of claim 2, wherein the voltage ring circuit comprises:

the first end of the delay charging circuit is used for accessing the start-stop reference signal, and the second end of the delay charging circuit is used for accessing the working voltage of the electric equipment;

and the first end of the first operational amplifier is connected with the third end of the delay charging circuit, the second end of the first operational amplifier is used for accessing the working voltage of the electric equipment, and the third end of the first operational amplifier is connected with the fourth end of the driving power supply.

4. The power supply circuit of claim 3, wherein the delay charging circuit comprises:

the first end of the voltage division module is used for accessing the working voltage of the electric equipment, the second end of the voltage division module is connected with the second end of the first operational amplifier, and the third end of the voltage division module is grounded;

the first end of the energy storage element is connected with the third end of the voltage division module, and the second end of the energy storage element is connected with the first end of the first operational amplifier;

and a first end of the compensation module is used for accessing the start-stop reference signal, and a second end of the compensation module is connected with the first end of the first operational amplifier and used for providing a compensation potential for the first end of the first operational amplifier.

5. The power supply circuit of claim 4, wherein the time delay charging circuit further comprises:

the first pole of the switching tube is connected with the third end of the start-stop control circuit, the second pole of the switching tube is connected with the first end of the energy storage element, and the third pole of the switching tube is connected with the second end of the energy storage element;

the start-stop control circuit is also used for outputting a reset signal to the first pole of the switch tube when the working control signal of the electric equipment is less than or equal to the start-stop reference signal, so that the switch tube is conducted.

6. The power supply circuit of claim 2, wherein the current loop circuit comprises:

and the first end of the second operational amplifier is used for accessing the working control signal of the electric equipment, the second end of the second operational amplifier is used for accessing the working voltage of the electric equipment, and the third end of the second operational amplifier is connected with the fourth end of the driving power supply.

7. The power supply circuit according to claim 1, wherein the driving power supply includes:

the controller is connected with the third end of the start-stop control circuit through an enabling end and the third end of the over-regulation inhibiting starting circuit through a feedback end _；

The first end of the power factor correction circuit is used for being connected with the external power supply, and the second end of the power factor correction circuit is connected with the first output end of the controller;

and the first end of the resonant converter is connected with the third end of the power factor correction circuit, the second end of the resonant converter is connected with the second output end of the controller, and the third end of the resonant converter is used for connecting the electric equipment.

8. The power supply circuit of claim 1, wherein the start-stop control circuit comprises:

the first end of the third operational amplifier is used for accessing the working control signal of the electric equipment, the second end of the third operational amplifier is used for accessing the start-stop reference signal, and the third end of the third operational amplifier is connected with the first end of the suppression overshoot starting circuit;

and the first end of the first photoelectric coupler is connected with the third end of the third operational amplifier, and the second end of the first photoelectric coupler is connected with the third end of the driving power supply.

9. The power supply circuit of claim 2, wherein the inhibit overshoot start-up circuit further comprises:

and the first end of the second photoelectric coupler is connected with the third end of the voltage ring circuit and the third end of the current ring circuit respectively, and the second end of the second photoelectric coupler is connected with the fourth end of the driving power supply.

10. The power supply circuit according to any one of claims 1 to 9, wherein the power supply circuit further comprises:

and the auxiliary power supply is used for supplying power to the start-stop control circuit, the driving power supply and the over-regulation restraining starting circuit.

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