CN212259393U - LED drive circuit - Google Patents
LED drive circuit Download PDFInfo
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- CN212259393U CN212259393U CN202020470247.0U CN202020470247U CN212259393U CN 212259393 U CN212259393 U CN 212259393U CN 202020470247 U CN202020470247 U CN 202020470247U CN 212259393 U CN212259393 U CN 212259393U
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Abstract
The utility model relates to the field of lighting technology, especially, relate to a LED drive circuit, include: the device comprises a rectification module, a constant current driving module, a comparison detection module and a pressure relief module; the pressure relief module is connected between the negative pole of the load and the ground end in series; the comparison detection module is connected with the pressure relief module and the constant current driving module, so that the output end voltage of the constant current driving module can be detected, when the output end voltage of the constant current driving module is detected to be greater than a first preset voltage, the switch unit in the pressure relief module is controlled to be in a disconnected state, the damping unit divides the voltage of the load, and when the output end voltage of the constant current driving module is detected to be smaller than a second preset voltage, the switch unit in the pressure relief module is controlled to be in a connected state, and the damping unit is in a short circuit. The utility model provides a LED drive circuit can restrain the impulse current that produces when electrified switch-on load under the on state, and then provides the protection for the load.
Description
Technical Field
The utility model belongs to the technical field of the illumination, especially, relate to a LED drive circuit.
Background
In recent years, LED (Light Emitting Diode) lighting is gradually replacing traditional Light sources such as incandescent lamps and fluorescent lamps with advantages of high Light efficiency, long service life, high reliability and no pollution. With the wide application of LED lighting, LED driving technology is becoming mature. The LED driving circuit is used for outputting constant current to an LED load so as to drive the LED lamp to normally work and mainly comprises a power level circuit and a control circuit. The control circuit controls the main switch tube in the power stage circuit to be conducted intermittently, so that the power stage circuit converts the received input voltage signal into a constant current signal and outputs the constant current signal to the LED load.
However, when the existing LED driving circuit is switched on with power in a power-on state, because a certain voltage difference exists during no-load, a large current is generated when the voltage difference passes through a load end, so that the load generates a large impact current, and the current and voltage fluctuation is obvious. In the above scenario, the transient current of the load is too large, which may cause a certain damage to the load, even directly disable the load.
SUMMERY OF THE UTILITY MODEL
In view of this, the embodiment of the present invention provides an LED driving circuit to solve the problem that the load is damaged when the existing LED driving circuit is powered on under the power-on state.
The embodiment of the utility model provides a LED drive circuit, include: the device comprises a rectification module, a constant current driving module, a comparison detection module and a pressure relief module; the pressure relief module comprises a damping unit and a switch unit;
the rectification module is connected with the power supply and is used for converting alternating current of the power supply into direct current;
the constant current driving module is connected with the rectifying module and used for converting the direct current into a constant current signal and outputting the constant current signal to the anode of a load;
the comparison detection module is connected with the pressure relief module and the constant current driving module and used for detecting the voltage of the output end of the constant current driving module, controlling the switch unit in the pressure relief module to be in a disconnected state when the voltage of the output end of the constant current driving module is detected to be greater than a first preset voltage so as to enable the damping unit to divide the voltage of the load, and controlling the switch unit in the pressure relief module to be in a connected state when the voltage of the output end of the constant current driving module is detected to be less than a second preset voltage so as to enable the damping unit to be in a short circuit state;
the pressure relief module is connected between the negative pole of the load and the ground end in series.
Optionally, the damping unit includes a first resistor; the switch unit includes a first switch; the first resistor and the first switch are connected in parallel.
Optionally, the comparison detecting module may include: a comparator control unit and a signal detection unit;
the signal detection unit is connected with the output end of the constant current driving module, and is used for receiving the voltage of the output end of the constant current driving module and outputting the voltage to the comparator control unit after voltage division;
the comparator control unit is connected with the signal detection unit and the first switch, and is used for receiving the divided voltage output by the signal detection unit, sending a first level signal to the first switch when the divided voltage is greater than a third preset voltage, and sending a second level signal to the first switch when the divided voltage is less than a fourth preset voltage; the first level signal is used for controlling the first switch to be in an off state so that the first resistor divides the voltage of the load; the second level signal is used for controlling the first switch to be in a conducting state so as to enable the first resistor to be in a short circuit.
Optionally, the LED driving circuit may further include: a power supply module;
and the power supply module is connected with the comparator control unit and the signal detection unit and used for supplying power to the comparator control unit and the signal detection unit.
Optionally, the comparator control unit may include: a second resistor and a comparator;
the first pin of the comparator is connected with the power supply module, the second pin of the comparator is connected with the power supply module after being connected with the second resistor, the third pin of the comparator is connected with the signal detection unit, the fourth pin of the comparator is connected with the first switch, and the fifth pin of the comparator is grounded.
Optionally, the third preset voltage and the fourth preset voltage may be reference voltages of the comparator;
correspondingly, the comparator is configured to output a low level signal to the first switch when the divided voltage output by the signal detection unit is greater than the reference voltage of the comparator, and output a high level signal to the first switch when the divided voltage is less than or equal to the reference voltage of the comparator.
The first switch is used for being in an off state when receiving the low level signal and being in an on state when receiving the high level signal.
Optionally, the rectifier module includes a bridge rectifier circuit.
Optionally, the constant current driving module includes: the constant current unit, the second switch, the transformer and the rectifying and filtering unit; the constant current unit is connected with the rectifying module; the second switch, the transformer, the rectification filter unit and the constant current unit are sequentially connected; the rectification filtering unit is connected with the positive electrode of the load;
the constant current unit is used for modulating the direct current output by the rectifying module into a primary constant current signal;
the transformer is used for modulating the primary constant current signal into a high-frequency pulse signal;
the rectification filtering unit is used for modulating the high-frequency pulse signal into a constant-current signal and outputting the constant-current signal to the anode of the load;
the second switch is used for being in a conducting state when the constant current unit is started and being in a disconnecting state when the constant current unit is in a standby state.
Optionally, the rectification filter unit includes: a diode and a capacitor;
the transformer and the diode form a first branch circuit; wherein the first branch is connected to a positive electrode of the load.
The transformer, the diode and the capacitor form a second branch circuit; wherein the second branch is grounded.
Optionally, the second switch includes: MOS tube, triode or relay.
The embodiment of the utility model provides a LED drive circuit, including rectifier module, constant current drive module, pressure release module and comparison detection module. The rectifier module is connected with the power supply, so that alternating current of the power supply can be converted into direct current. The constant current driving module is connected with the rectifying module, so that the direct current can be converted into a constant current signal and output to the anode of the load. By arranging the comparison detection module, the output end voltage of the constant current driving module can be detected. When the voltage exceeds the first preset voltage, the no-load state can be judged, the switch unit in the pressure relief module is controlled to be in the off state, after the load is connected in the off state, the pressure relief module is connected in series with the negative pole and the ground end of the load, so that the pressure difference caused by no-load can firstly pass through the damping unit, and the generated impact current is reduced under the influence of the damping action, and the effect of protecting the load is achieved. When the voltage of the output end of the constant current driving module is detected to be smaller than the second preset voltage, the fact that the voltage of the output end of the constant current driving module cannot damage a load at the moment can be judged, the load is in a normal load state at the moment, the damping unit is in a short circuit state through controlling the switch unit to be in a conducting state, and therefore the circuit works in a normal state.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of an LED driving circuit provided in an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an LED driving circuit including a first switch and a first resistor according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an LED driving circuit including a comparator control unit and a signal detection unit according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an LED driving circuit including a power supply module according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a comparator control unit according to an embodiment of the present invention;
fig. 6 is a schematic circuit diagram of an LED driving circuit according to another embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
In order to explain the technical solution described in the present application, the following description will be given by way of specific examples.
Fig. 1 is a schematic structural diagram of an LED driving circuit provided in this embodiment, and referring to fig. 1, the LED driving circuit is used in connection with a power supply and a load, and includes: the constant current detection circuit comprises a rectification module 100, a constant current driving module 200, a comparison detection module 300 and a pressure relief module 400; wherein the pressure relief module 400 includes a damping unit 410 and a switching unit 420.
The rectifying module 100 is connected to the power supply and is configured to convert ac power of the power supply into dc power.
The embodiment of the utility model provides an in, the power can be the commercial power, for supplying the LED load to use, sets up rectifier module and tentatively converts the alternating current into the direct current.
The constant current driving module 200 is connected to the rectifying module 100, and is configured to convert the direct current into a constant current signal and output the constant current signal to the positive electrode of the load.
The comparison detection module 300 is connected to the voltage relief module 400 and the constant current driving module 200, and is configured to detect the voltage at the output end of the constant current driving module 200, and when detecting that the voltage at the output end of the constant current driving module 200 is greater than a first preset voltage, control the switch unit 410 in the voltage relief module 400 to be in an off state, so that the damping unit 420 divides the voltage of the load, and when detecting that the voltage at the output end of the constant current driving module 200 is less than a second preset voltage, control the switch unit 410 in the voltage relief module 400 to be in an on state, so that the damping unit 420 is in a short circuit state.
The embodiment of the present invention provides an embodiment, the switch unit 410 can select rules according to the circumstances, and can be a relay, an MOS Transistor (Metal-Oxide-Semiconductor Field-Effect Transistor) or a triode, and the switch that can change the on-state according to the level of the comparison detection module 300 is all applicable. The damping unit 420 may include one or more resistors, which are set according to actual conditions. The damping unit 420 and the switching unit 410 may be connected in parallel, such that when the switching unit 410 is turned on, the damping unit 420 is short-circuited, and when the switching unit 410 is turned off, the damping unit and the load are connected in series. The comparison detection module 300 and the voltage relief module 400 may also be converted into other logical judgment relationships according to the connection relationship between the switch unit 410 and the damping unit 420, for example, the number of switches in the switch unit 410 is multiple, the number of resistors in the damping unit 420 is multiple, and a more complex connection relationship between the switches and the damping unit 420 may be constructed, so that when the switch unit 410 is in a conducting state, the damping unit 420 may divide the voltage of the load, and at this time, when it is detected that the voltage of the output end of the constant current driving module 200 is greater than the first preset voltage, the switch unit 410 is controlled to be conducted. Under such a connection relationship, when the voltage of the output terminal of the constant current driving module 200 is smaller than the first preset voltage, the switch unit 410 is controlled to be turned off, and the damping unit 420 is short-circuited. In this embodiment, the first preset voltage and the second preset voltage may be set according to a no-load voltage and a loaded voltage of the LED driving circuit. For example, the no-load voltage is 50V, the on-load voltage is 36V, the first preset voltage may be set to 45V, the second preset voltage may be set to 40V, the first preset voltage is greater than or equal to the second preset voltage and may be within the range of the no-load voltage and the on-load voltage, and the setting may be performed according to actual conditions.
The voltage relief module 400 is connected in series between the negative pole of the load and the ground.
The embodiment of the utility model provides a LED drive circuit, including rectifier module 100, constant current drive module 200, comparison detection module 300 and pressure release module 400. By connecting the rectifying module 100 with the power supply, the alternating current of the power supply can be converted into direct current. By connecting the constant current driving module 200 with the rectifying module 100, the direct current can be converted into a constant current signal and output to the anode of the load. By providing the comparison detection module 300, the output terminal voltage of the constant current driving module 200 can be detected. When the voltage exceeds the first preset voltage, the no-load state can be determined, and the switch unit 410 in the voltage relief module 400 is controlled to be in the off state, after the load is connected in the off state, because the voltage relief module 400 is connected in series to the negative electrode and the ground end of the load, the voltage difference caused by no-load can firstly pass through the damping unit 420, and the impact current generated along with the voltage difference is reduced under the influence of the damping effect, so that the effect of protecting the load is achieved. When the voltage at the output end of the constant current driving module 200 is detected to be lower than the second preset voltage, it can be determined that the voltage at the output end of the constant current driving module 200 does not damage the load, and the load is in a normal on-load state at this time, and the damping unit 420 is short-circuited by controlling the switch unit 420, so that the circuit works in a normal state.
In some embodiments, the damping unit comprises a first resistor; the switch unit includes a first switch; the first resistor and the first switch are connected in parallel.
In the embodiment of the present invention, referring to fig. 2, the damping unit may include a first resistor 421, the switch unit may include a first switch 411, the first resistor 421 is connected in parallel with the first switch 411, for making the first switch 411 on, the first resistor 421 is short-circuited, when the first switch 411 is disconnected, the first resistor 421 and the load are in a series state. The first switch 411 may select a triode, an MOS transistor or a relay according to actual conditions, a first terminal of the first switch 411 is connected to a negative electrode of a load, a second terminal of the first switch is grounded, a third terminal of the first switch is connected to the comparison detection module 300, an on-off state is changed according to a received level signal of the comparison detection module 300, and the first resistor 421 is connected in parallel to the first terminal and the third terminal of the first switch 411. The device is simple in components and low in cost, and can reduce the impact current and protect the load simply and conveniently.
In some embodiments, the comparison detection module comprises: a comparator control unit and a signal detection unit; the signal detection unit is connected with the output end of the constant current driving module, and is used for receiving the voltage of the output end of the constant current driving module and outputting the voltage to the comparator control unit after voltage division; the comparator control unit is connected with the signal detection unit and the first switch, and is used for receiving the divided voltage output by the signal detection unit, sending a first level signal to the first switch when the divided voltage is greater than a third preset voltage, and sending a second level signal to the first switch when the divided voltage is less than a fourth preset voltage; the first level signal is used for controlling the first switch to be in an off state so that the first resistor divides the voltage of the load; the second level signal is used for controlling the first switch to be in a conducting state so as to enable the first resistor to be in a short circuit.
In the embodiment of the present invention, referring to fig. 3, the comparison detection module may include a comparator control unit 320 and a signal detection unit 310. For the output end voltage of the general LED driving circuit, the output end voltage is larger than the reference voltage of the comparator control unit 320 for comparison and judgment, and in order to expand the selection range of the devices of the comparator control unit 320 and reduce the implementation difficulty, the signal detection unit 310 may be arranged to be connected between the comparator control unit 320 and the output end of the constant current driving module 200 as a transition. The detection unit 310 may collect the voltage at the output end of the constant current driving module 200, and output the voltage at the output end to the comparator control unit 320 by dividing the voltage and reducing the voltage at the output end proportionally. Specifically, the signal detection unit 310 may be a voltage division circuit formed by several resistors, or a signal detection IC capable of implementing a voltage division function. Accordingly, the comparator control unit 320 may select a voltage within the self voltage application range as the third preset voltage and the fourth preset voltage. Specifically, the comparator control unit may be a comparator of each type, execute a function of comparing and determining the input signal with the third preset voltage and the fourth preset voltage, and output different level signals according to a comparison result, so as to control the on-off state of the first switch 411.
In some embodiments, the LED driving circuit may further include: a power supply module; and the power supply module is connected with the comparator control unit and the signal detection unit and used for supplying power to the comparator control unit and the signal detection unit.
In the embodiment of the present invention, referring to fig. 4, the LED driving circuit may further include a power supply module 500, and the power supply module 500 may be an independent voltage source or a circuit with voltage processing function connected to the mains. When the power supply module is connected to the mains supply, the voltage can be stepped down for multiple times, so as to provide a stable working voltage for the comparator control unit 320. Accordingly, when the signal detection unit includes the signal detection IC, the power supply module 500 also provides the signal detection unit 310 with the operating voltage.
In some embodiments, the comparator control unit may include: a second resistor and a comparator; the first pin of the comparator is connected with the power supply module, the second pin of the comparator is connected with the power supply module after being connected with the second resistor, the third pin of the comparator is connected with the signal detection unit, the fourth pin of the comparator is connected with the first switch, and the fifth pin of the comparator is grounded.
In the embodiment of the present invention, referring to fig. 5, the comparison controller unit 320 may include a second resistor R2 and a comparator B. And a first pin of the comparator B is connected with the power supply module. And a second pin of the comparator B is connected with the power supply module after being connected with a second resistor R2, and is used for providing the internal reference voltage of the comparator. And a third pin of the comparator B is connected with the signal detection unit and used for receiving the divided voltage of the signal detection unit through the third pin to carry out comparison and judgment. And a fourth pin of the comparator B is connected with the first switch and used for outputting a level signal to the first switch according to a judgment result. And the fifth pin of the comparator B is grounded.
In some embodiments, the third preset voltage and the fourth preset voltage are reference voltages of the comparator; correspondingly, the comparator is configured to output a low level signal to the first switch when the divided voltage output by the signal detection unit is greater than the reference voltage of the comparator, and output a high level signal to the first switch when the divided voltage is less than the reference voltage of the comparator; the first switch is used for being in an off state when receiving the low level signal and being in an on state when receiving the high level signal.
In the embodiment of the present invention, referring to fig. 5, the third preset voltage and the fourth preset voltage are the reference voltage of the comparator B; the comparator B receives the divided voltage output by the signal detection unit through a third pin, outputs a low level signal to the first switch through a fourth pin when judging that the divided voltage is greater than the reference voltage of the comparator, and outputs a high level signal to the first switch through the fourth pin when judging that the divided voltage is less than or equal to the reference voltage of the comparator; accordingly, at this time, the first switch may be set to be in an off state when receiving the low level signal and to be in an on state when receiving the high level signal.
In some embodiments, the rectifier module comprises a bridge rectifier circuit.
In the embodiment of the utility model, a bridge rectifier circuit is adopted to carry out AC/DC conversion, the bridge rectifier circuit is a circuit which utilizes the one-way conductivity of diodes to carry out rectification, the bridge rectifier utilizes four diodes to be butted in pairs, and the positive half part of an input sine wave is conducted by two pipes to obtain positive output; when the negative half part of the sine wave is input, the other two tubes are conducted, and because the two tubes are reversely connected, the output still obtains the positive half part of the sine wave. Bridge rectification is higher for half-wave rectification to the utilization efficiency of input sine wave, is applicable to the LED drive circuit in this application.
In some embodiments, the constant current driving module may include: the constant current unit, the second switch, the transformer and the rectifying and filtering unit; the constant current unit is connected with the rectifying module; the second switch, the transformer, the rectification filter unit and the constant current unit are sequentially connected; the rectification filtering unit is connected with the positive electrode of the load; the constant current unit is used for modulating the direct current output by the rectifying module into a primary constant current signal; the transformer is used for modulating the primary constant current signal into a high-frequency pulse signal; the rectification filtering unit is used for modulating the high-frequency pulse signal into a constant-current signal and outputting the constant-current signal to the anode of the load; the second switch is used for being in a conducting state when the constant current unit is started and being in a disconnecting state when the constant current unit is in a standby state.
In the embodiment of the present invention, fig. 6 is a schematic diagram of a circuit structure of an LED driving circuit according to another embodiment of the present invention, referring to fig. 6, the power supply of the LED driving circuit is a commercial power, the rectifier module 100 is a bridge rectifier circuit, the first end of the bridge rectifier circuit is connected to a live wire, the third end of the bridge rectifier circuit is connected to a zero line, the fourth end is grounded, and the second end outputs a direct current to the constant current unit 210; after the constant current unit 210 processes the direct current, a primary constant current signal is output to the transformer T1 through the second switch Q2; a third terminal of the second switch Q2 is connected to the output terminal of the constant current unit 210, a second terminal of the second switch Q2 is grounded, a first terminal of the second switch Q2 is connected to the transformer T1, and the second switch may be a transistor, an MOS transistor, or a relay, and is configured to be in a conducting state when the constant current unit 210 is turned on and be in a disconnecting state when the constant current unit 210 is in standby. The transformer T1 is used for modulating the primary constant current signal into a high-frequency pulse signal; the rectification filtering unit 220 is configured to modulate the high-frequency pulse signal into a constant current signal and output the constant current signal to the positive electrode of the load; the LED1 and the LED2 are loads, Q1 is a first switch, and R1 is a first resistor.
In some embodiments, the rectifying and filtering unit includes: a diode and a capacitor; the transformer and the diode form a first branch circuit; wherein the first branch is connected to the positive electrode of the load; the transformer, the diode and the capacitor form a second branch circuit; wherein the second branch is grounded.
In the embodiment of the present invention, referring to fig. 6, the rectifying and filtering unit 220 includes: a diode D1 and a capacitor C1; the transformer T1 and the diode D1 form a first branch, and the first branch is connected with the anode of the load; the transformer T1, the diode D1 and the capacitor C1 form a second branch, and the second branch is grounded.
In some embodiments, the second switch comprises: MOS tube, triode or relay.
Above-mentioned utility model provides an embodiment, through set up rectifier module with the power is connected, can be with the alternating current conversion of power for the direct current. The constant current driving module is connected with the rectifying module, so that the direct current can be converted into a constant current signal and output to the anode of the load. Because the on-load voltage and the no-load voltage of the output end of the constant current driving module are higher relative to the comparison control module, the comparator control module is arranged to acquire the voltage of the output end of the constant current driving module and output the voltage to the comparator control module after voltage division, so that the comparator control module can indirectly detect the voltage of the output end of the constant current driving module through the divided voltage output by the signal detection module and change the on-off state of the first switch according to the voltage of the output end of the constant current driving module. When the divided voltage received by the comparator control module exceeds a first preset voltage, the output end of the constant current driving module can be judged to be in an idle state at the moment, the comparator control module controls the pressure relief module connected with the negative electrode of the load to be in a disconnected state at the moment, the pressure relief module comprises a first switch and a first resistor which are connected in parallel, when the first switch is disconnected, after the first switch is connected into the load in the disconnected state, the first resistor is connected with the load in series, the pressure difference caused by idle load passing through the first resistor is firstly reduced under the influence of a damping effect, and therefore the effect of protecting the load is achieved. When the divided voltage received by the comparator control module is smaller than the second preset voltage, the output end voltage of the constant current driving module can be judged not to damage the load at the moment, the load is in a normal load state at the moment, and the first resistor is short-circuited by controlling the conduction of the first switch, so that the circuit works in a normal state.
It will be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing functional units and models are merely illustrated as being divided, and in practical applications, the foregoing functional allocations may be performed by different functional units and modules as needed, that is, the internal structure of the device may be divided into different functional units or modules to perform all or part of the above described functions. Each functional unit and module in the embodiments may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill 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 substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. An LED driver circuit for use in connection with a power supply and a load, comprising: the device comprises a rectification module, a constant current driving module, a comparison detection module and a pressure relief module; the pressure relief module comprises a damping unit and a switch unit;
the rectification module is connected with the power supply and is used for converting alternating current of the power supply into direct current;
the constant current driving module is connected with the rectifying module and used for converting the direct current into a constant current signal and outputting the constant current signal to the anode of a load;
the comparison detection module is connected with the pressure relief module and the constant current driving module and used for detecting the voltage of the output end of the constant current driving module, controlling the switch unit in the pressure relief module to be in a disconnected state when the voltage of the output end of the constant current driving module is detected to be greater than a first preset voltage so as to enable the damping unit to divide the voltage of the load, and controlling the switch unit in the pressure relief module to be in a connected state when the voltage of the output end of the constant current driving module is detected to be less than a second preset voltage so as to enable the damping unit to be in a short circuit state;
the pressure relief module is connected between the negative pole of the load and the ground end in series.
2. The LED driver circuit according to claim 1,
the damping unit comprises a first resistor;
the switch unit includes a first switch;
the first resistor and the first switch are connected in parallel.
3. The LED driving circuit according to claim 2, wherein the comparison detection module comprises: a comparator control unit and a signal detection unit;
the signal detection unit is connected with the output end of the constant current driving module, and is used for receiving the voltage of the output end of the constant current driving module and outputting the voltage to the comparator control unit after voltage division;
the comparator control unit is connected with the signal detection unit and the first switch, and is used for receiving the divided voltage output by the signal detection unit, sending a first level signal to the first switch when the divided voltage is greater than a third preset voltage, and sending a second level signal to the first switch when the divided voltage is less than a fourth preset voltage; the first level signal is used for controlling the first switch to be in an off state so that the first resistor divides the voltage of the load; the second level signal is used for controlling the first switch to be in a conducting state so as to enable the first resistor to be in a short circuit.
4. The LED driving circuit according to claim 3, further comprising: a power supply module;
and the power supply module is connected with the comparator control unit and the signal detection unit and used for supplying power to the comparator control unit and the signal detection unit.
5. The LED drive circuit according to claim 4, wherein the comparator control unit includes: a second resistor and a comparator;
the first pin of the comparator is connected with the power supply module, the second pin of the comparator is connected with the power supply module after being connected with the second resistor, the third pin of the comparator is connected with the signal detection unit, the fourth pin of the comparator is connected with the first switch, and the fifth pin of the comparator is grounded.
6. The LED driving circuit according to claim 5, wherein the third preset voltage and the fourth preset voltage are reference voltages of the comparator;
correspondingly, the comparator is configured to output a low level signal to the first switch when the divided voltage output by the signal detection unit is greater than the reference voltage of the comparator, and output a high level signal to the first switch when the divided voltage is less than or equal to the reference voltage of the comparator;
the first switch is used for being in an off state when receiving the low level signal and being in an on state when receiving the high level signal.
7. The LED driving circuit according to claim 1, wherein the rectifying module comprises a bridge rectifier circuit.
8. The LED driving circuit according to claim 1, wherein the constant current driving module includes: the constant current unit, the second switch, the transformer and the rectifying and filtering unit; the constant current unit is connected with the rectifying module; the second switch, the transformer, the rectification filter unit and the constant current unit are sequentially connected; the rectification filtering unit is connected with the positive electrode of the load;
the constant current unit is used for modulating the direct current output by the rectifying module into a primary constant current signal;
the transformer is used for modulating the primary constant current signal into a high-frequency pulse signal;
the rectification filtering unit is used for modulating the high-frequency pulse signal into a constant-current signal and outputting the constant-current signal to the anode of the load;
the second switch is used for being in a conducting state when the constant current unit is started and being in a disconnecting state when the constant current unit is in a standby state.
9. The LED driving circuit according to claim 8, wherein the rectifying-filtering unit includes: a diode and a capacitor;
the transformer and the diode form a first branch circuit; wherein the first branch is connected to the positive electrode of the load;
the transformer, the diode and the capacitor form a second branch circuit; wherein the second branch is grounded.
10. The LED driving circuit according to any one of claims 8 to 9, wherein the second switch includes: MOS tube, triode or relay.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020470247.0U CN212259393U (en) | 2020-04-02 | 2020-04-02 | LED drive circuit |
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| CN202020470247.0U CN212259393U (en) | 2020-04-02 | 2020-04-02 | LED drive circuit |
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| CN212259393U true CN212259393U (en) | 2020-12-29 |
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| CN202020470247.0U Active CN212259393U (en) | 2020-04-02 | 2020-04-02 | LED drive circuit |
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| CN (1) | CN212259393U (en) |
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