CN221202358U - Driving circuit and lighting device - Google Patents
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- CN221202358U CN221202358U CN202323095524.7U CN202323095524U CN221202358U CN 221202358 U CN221202358 U CN 221202358U CN 202323095524 U CN202323095524 U CN 202323095524U CN 221202358 U CN221202358 U CN 221202358U
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Abstract
The utility model relates to the technical field of circuits, in particular to a driving circuit and a lighting device. The driving circuit in the technical scheme comprises a rectifying unit, an energy storage unit, a switching unit, a load unit, a current source and a control circuit, wherein the energy storage unit and the switching unit are connected in series, and the rectifying unit is connected in parallel to two ends of a series body formed by the energy storage unit and the switching unit; the load unit and the current source are connected in series, and the rectifying unit is connected in parallel to two ends of a serial body formed by the load unit and the current source; one end of the control circuit is connected with the current source, the other end of the control circuit is connected with the control end of the switching unit, and the control circuit responds to the voltage values at two ends of the current source or the current value flowing through the current source to be smaller than a preset threshold value, and controls the switching unit to discharge the energy storage unit. The driving circuit can carry out finer and more effective regulation and control on elements with charge and discharge functions in the circuit, so that the fluctuation range of the output voltage of the circuit is reduced while the power factor in the circuit is improved.
Description
Technical Field
The utility model relates to the technical field of circuits, in particular to a driving circuit and a lighting device.
Background
Two types of driving circuits commonly used for LED lighting devices include a linear driving circuit and a switching power supply, wherein the switching power supply is widely used with the advantages of high efficiency and small volume.
Fig. 1 is an active power factor correction circuit in the prior art. The inductor 103, the field effect transistor 106 and the diode 104 form a switch boost circuit topology, the capacitor 105 is used for filtering and storing output voltage, the resistor 108 and the resistor 109 are used for generating alternating current phase voltage signals, the resistor 111 and the resistor 112 are used for detecting output voltage signals, and the output voltage signals are fed into the PFC control circuit to generate a signal related to output voltage and alternating current waveforms, so that current flowing through the resistor 110 is controlled. Further, the current waveform flowing through the field effect transistor 106 and the inductor 103 is related to the phase voltage of the alternating current, and the amplitude is related to the output voltage, so that the purpose of power factor correction is achieved. This approach achieves high power factor performance approaching 1, with the disadvantage of complex circuitry and high cost, and in addition, the output voltage must be higher than the peak value of the input ac voltage, requiring the semiconductor switching devices of the latter stage switching power supply to withstand higher voltage stresses, which requires higher semiconductor device costs.
Fig. 2 is a prior art passive valley-fill circuit, which has the following operation modes:
When the phase voltage of the alternating current 201 is greater than the sum of the voltages of the energy storage capacitor 203 and the energy storage capacitor 204, the diode 206 and the diode 207 are cut off, the diode 205 and the rectifier bridge 202 are conducted, and the alternating current supplies power to the energy storage capacitor 203 and the energy storage capacitor 204 through the rectifier bridge 202 and the diode 205 and also supplies power to a load. During this period, the storage capacitor 203 and the storage capacitor 204 are respectively charged to half the peak voltage of the alternating current 201; when the phase voltage of the alternating current 201 is less than half of the peak voltage, the energy storage capacitor 203 discharges the load through the diode 206 and the energy storage capacitor 204 and the diode 207, and at the moment, the rectifier bridge 202 and the diode 205 are both reversely cut off; when the phase voltage of the alternating current 201 is at the peak value and half of the peak value, the alternating current 201 directly supplies power to the load through the rectifier bridge 202, the diode 205, the diode 206 and the diode 207 are all reversely cut off, and the energy storage capacitor voltage is kept unchanged. The power factor of the scheme is lower than that of the active power factor correction circuit shown in fig. 1, but the circuit is simpler, the cost is lower, and the scheme is widely applied to products with lower power and sensitive cost such as energy-saving lamps, LED illumination and the like. The minimum value of the output voltage of the passive valley-fill circuit is less than half of the peak value of the alternating current, which requires that the post-stage switching power supply is suitable for a wider input voltage range, thus leading to the reduction of the performance index and the increase of the cost of the post-stage switching power supply and also leading to the limitation of the application of the passive valley-fill circuit.
Thus, there is still a need for a power factor correction circuit that has no additional rise in output voltage and a small fluctuation range of output voltage.
Disclosure of utility model
In view of the above problems, the present utility model provides a driving circuit and a lighting device, where the driving circuit can perform finer and more effective regulation and control on elements with charge and discharge functions in the circuit, so as to reduce the fluctuation range of the output voltage of the circuit while improving the power factor of the circuit.
In the technical scheme of the utility model, the driving circuit comprises a rectifying unit, an energy storage unit, a switching unit, a load unit, a current source and a control circuit, wherein the energy storage unit and the switching unit are connected in series, and the rectifying unit is connected in parallel to two ends of a series body formed by the energy storage unit and the switching unit; the load unit and the current source are connected in series, and the rectifying unit is connected in parallel to two ends of a serial body formed by the load unit and the current source; one end of the control circuit is connected with the current source, the other end of the control circuit is connected with the control end of the switching unit, and the control circuit responds to the voltage values at two ends of the current source or the current value flowing through the current source to be smaller than a preset threshold value, and controls the switching unit to discharge the energy storage unit.
According to the technical scheme of the utility model, the rectification unit rectifies an alternating voltage signal input by an external power supply, and output voltage output by the rectification unit can supply power for a series body formed by the energy storage unit and the switch unit and/or a series body formed by the load unit and the current source; the switch unit is connected with the energy storage unit in series to control the energy storage unit to switch working states such as charging and discharging. The control circuit responds to the fact that the voltage values at two ends of the current source or the current value flowing through the current source is smaller than the preset threshold value, and controls the switch unit to enable the energy storage unit to discharge, and the load unit, namely the voltage values at two ends of the current source or the current value flowing through the current source, is increased when the voltage values at two ends of the current source or the current value flowing through the current source is smaller than the preset threshold value; after the voltage values at two ends of the current source or the current value flowing through the current source is increased to be greater than or equal to a preset threshold value, the switch unit is controlled to stop discharging the energy storage unit, namely, the control circuit enables the voltage values at two ends of the current source or the current value flowing through the current source to be smaller than the preset threshold value and can be maintained at a stable value according to feedback adjustment of the voltage values at two ends of the current source or the current value flowing through the current source. In other words, the output voltage fluctuation range of the drive circuit is small, that is, the value of the current flowing through the load unit connected in series with the current source can be stabilized, and the connection of the elements in the whole drive circuit is simple and the cost is low.
In the technical scheme of the utility model, the switch unit in the driving circuit comprises a charging switch and a discharging switch which are connected in parallel, the charging switch is configured to be turned on in response to the voltage at two ends of the rectifying unit being greater than the voltage at two ends of the energy storage unit, and the charging switch is turned off otherwise; the discharge switch is configured to be turned on in response to a voltage value across the current source or a current value flowing through the current source being less than a preset threshold, and to be turned off otherwise.
According to the technical scheme of the utility model, when the voltage values at the two ends of the current source or the current value flowing through the current source is smaller than the preset threshold value, the energy storage unit discharges, and the external power supply and the energy storage unit simultaneously supply power to the load unit, so that the load unit can still conduct work under the condition that the output voltage of the external power supply is lower, namely the output voltage of the external power supply is allowed to be lower. If the external power supply is configured as alternating current mains supply, the current conduction angle of the alternating current mains supply is expanded, and the power factor of the whole circuit is improved. When the output voltage of the external power supply is larger than a preset threshold value and smaller than the voltage at two ends of the energy storage unit, the energy storage unit does not work; when the output voltage of the external power supply is larger than the voltage at two ends of the energy storage unit, the energy storage unit is charged, and the external power supply supplies power to the load unit and the energy storage unit simultaneously, so that the part of the output voltage exceeding the voltage of the load unit can be effectively utilized, and the overall electric energy conversion efficiency of the driving circuit is improved.
Preferably, in the technical solution of the present utility model, the charging switch in the driving circuit is configured as a diode.
According to a preferred embodiment of the utility model, the diode is capable of controlling the current flow through the energy storage unit.
Preferably, in the technical solution of the present utility model, the current source in the driving circuit is configured as a variable current source controlled by an external signal.
According to the technical scheme of the utility model, the preset threshold value can be set according to an external signal, namely, the discharging condition of the energy storage unit is controlled, so that the constant value of the current source when the constant output is kept can be controlled, and the stable dimming control can be realized when the load unit is an LED lighting unit.
In the technical scheme of the utility model, the current source comprises a first power tube, one end of the first power tube is connected with the load unit, and the other end of the first power tube is connected with the grounding end through a first resistor.
In the technical scheme of the utility model, the control circuit comprises a second power tube and a second amplifier, wherein one end of the second power tube is connected with the control end of the discharge switch, and the other end of the second power tube is connected with the grounding end; and the second amplifier controls the second power tube to be conducted in response to the fact that the current of the first power tube is lower than a preset threshold value.
In the technical scheme of the utility model, the control circuit comprises a third power tube and a third amplifier, one end of the third power tube is connected with the control end of the discharge switch, and the other end of the third power tube is connected with the grounding end; and the third amplifier controls the third power tube to be conducted in response to the drain voltage of the first power tube being lower than a preset threshold value.
In the technical scheme of the utility model, the utility model also provides a lighting device, which comprises the driving circuit.
Drawings
FIG. 1 is a schematic diagram of a prior art drive circuit;
Fig. 2 is a schematic diagram of another driving circuit provided in the first embodiment of the present utility model.
Fig. 3 is a schematic diagram of a driving circuit provided in the first embodiment of the present utility model.
Fig. 4 is a schematic diagram of a driving circuit provided in a second embodiment of the present utility model.
Fig. 5 is a schematic diagram of a driving circuit provided in a third embodiment of the present utility model.
Reference numerals illustrate: the device comprises a 1-rectifying unit, a 2-energy storage unit, a 3-switching unit, a 31-charging switch, a 32-discharging switch, a 4-load unit, a 5-current source and a 6-control circuit.
Detailed Description
The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model.
[ First embodiment ]
Fig. 3 is a schematic diagram of a driving circuit of a lighting device according to a first embodiment of the present utility model.
As shown in fig. 3, in a first embodiment of the present utility model, there is provided a driving circuit including a rectifying unit 1, an energy storage unit 2, a switching unit 3, a load unit 4, a current source 5, and a control circuit 6.
The rectification unit 1 is connected to an external power supply U S, the external power supply U S may be set as ac mains, and the rectification unit 1 rectifies the ac mains input by the external power supply U S to obtain a dc voltage signal, i.e. a voltage V S across the rectification unit 1.
The energy storage unit 2 and the switching unit 3 are connected in series, and when the switching unit 3 is in different on/off states, the energy storage unit 2 connected in series with the switching unit is charged, discharged, or does not perform charging/discharging operation. The rectifying unit 1 is connected in parallel with two ends of a series body formed by the energy storage unit 2 and the switch unit 3, and the rectifying unit 1 can charge the energy storage unit 2 through the switch unit 3.
The load unit 4 and the current source 5 are connected in series, and the operating state of the load unit 4 can be reflected by the voltage value across the current source 5 or the current value flowing through the current source 5. The rectifying unit 1 is connected in parallel to two ends of a serial body formed by the load unit 4 and the current source 5, and the rectifying unit 1 can supply power to the load unit 4 through the current source 5. Likewise, the series body formed by the energy storage unit 2 and the switch unit 3 is connected in parallel with the series body formed by the load unit 4 and the current source 5, and the energy storage unit 2 can supply power to the load unit 4 through the switch unit 3 and the current source 5 when discharging.
In an embodiment of the utility model, the load unit 4 is configured as an LED lighting unit, and the driving circuit is configured as a driving circuit of an LED lighting device, respectively, the current source 5 in the driving circuit being configured as a variable current source controlled by an external signal. The external signal may be a dimming control signal of the LED lighting device such as an analog signal or a PWM signal.
One end of the control circuit 6 is connected with the current source 5, and detects the working parameters of the current source 5 to obtain a voltage value V 1 at two ends of the current source 5 or a current value I 1 flowing through the current source 5. The other end of the control circuit 6 is connected with the control end of the switch unit 3, and can control the on/off state of the switch unit 3, so as to control the charge and discharge or not to perform charge and discharge actions of the energy storage unit 2 connected in series with the switch unit 3.
In the embodiment of the present utility model, the control circuit 6 controls the switch unit 3 to discharge the energy storage unit 2 connected in series with the switch unit 3 in response to the voltage V 1 across the current source 5 or the current I 1 flowing through the current source 5 being smaller than the preset threshold, and the parameter of the load unit 4, such as the current value I 1 flowing through the current source 5, is increased; after the current value I 1 flowing through the current source 5 increases to be greater than or equal to the preset threshold, the switch unit 3 is controlled to stop discharging the energy storage unit 2, that is, the control circuit 6 adjusts according to the feedback of the current value I 1 flowing through the current source 5, so that the current value I 1 flowing through the current source 5 can be maintained at a stable value, and the stable value can be the preset threshold or a value corresponding to the preset threshold. The value of the current flowing through the load unit 4 connected in series with the current source 5 can be stabilized, and when the load unit 4 is configured as an LED light emitting unit, the luminance of the LED light emitting unit can be kept stable. In other words, the output voltage of the drive circuit, that is, the operating voltage of the load unit 4 can be maintained at a stable value, and the output voltage fluctuation range of the drive circuit is small.
Preferably, in the embodiment of the present utility model, the switching unit 3 in the driving circuit includes a charge switch 31 and a discharge switch 32 connected in parallel. In response to the voltage V S across the rectifying unit 1 being greater than the voltage V C across the energy storage unit 2, the charging switch 31 is turned on, the voltage V S across the rectifying unit 1 charges the energy storage unit 2 through the charging switch 31, otherwise the charging switch 31 is turned off, and the energy storage unit 2 stops charging. In response to the detection value of the current source 5 (taking the detection value of the current source 5 as the voltage value V 1 at two ends of the current source 5 as an example) being smaller than the preset threshold, the discharge switch 32 is turned on, the energy storage unit 2 discharges to the load unit 4 through the discharge switch 32, otherwise, the discharge switch 32 is turned off, and the discharge of the energy storage unit 2 is stopped.
In the embodiment of the present utility model, in response to the voltage value V 1 across the current source 5 or the current value I 1 flowing through the current source 5 being smaller than the preset threshold, the energy storage unit 2 discharges, and the external power supply U S and the energy storage unit 2 simultaneously supply power to the load unit 4, so that the load unit 4 can still perform the on operation when the voltage V S across the rectifying unit 1 is lower. If the external power supply U S is configured as alternating current mains supply, the current conduction angle of the alternating current mains supply is expanded, and the power factor of the whole circuit is improved. When the voltage V S at two ends of the rectifying unit 1 is greater than the voltage V C at two ends of the energy storage unit 2, the energy storage unit 2 is charged, and the external power supply U S supplies power to the load unit 4 and the energy storage unit 2at the same time, so that the output voltage, that is, the part of the voltage V S at two ends of the rectifying unit 1, exceeding the voltage of the load unit 4 can be effectively utilized, and the overall electric energy conversion efficiency of the driving circuit is improved.
[ Second embodiment ]
Fig. 4 is a schematic diagram of a driving circuit of a lighting device according to a second embodiment of the present utility model.
As shown in fig. 4, the second embodiment of the present utility model is further optimized based on the first embodiment, and a driving circuit is provided in the second embodiment of the present utility model. Comprises a rectifying unit 1, an energy storage unit 2, a switching unit 3, a load unit 4, a current source 5 and a control circuit 6.
The rectifying unit 1 is composed of a plurality of diodes, and the energy storage unit 2 is configured as an energy storage capacitor C 1. In other embodiments of the present utility model, the energy storage unit 2 may be configured as a capacitor or other type of energy storage element or circuit capable of performing a charging and discharging operation, which is not limited herein.
The charging switch 31 in the switch unit 3 is configured with a diode D 1, the anode of the diode D 1 is connected to the rectifying unit 1, the cathode is connected to the storage capacitor C 1, and the diode D 1 can limit the current flowing in the storage capacitor C 1 during discharging/charging, i.e. when the storage capacitor C 1 is charged, the current can flow into the storage capacitor C 1 forward through the diode D 1, and when the storage capacitor C 1 is discharged, the current is prevented from flowing out of the storage capacitor C 1 backward through the diode D 1.
The discharging switch 32 is configured as a PNP transistor SW 1, the collector C of the transistor SW 1 is connected to the rectifying unit 1, the emitter e is connected to the storage capacitor C 1, and the base b is connected to the control circuit 6. The control circuit 6 can control the on/off of the transistor SW 1 through simple high-low level switching, and when the transistor SW 1 is on, the discharging current of the storage capacitor C 1 flows to the load unit 4 through the transistor SW 1 to supply power to the load unit 4.
In other embodiments of the present utility model, the charge switch 31 and the discharge switch 32 in the switch unit 3 may be configured as other elements or circuits capable of achieving functions such as switching, unidirectional conduction, etc., such as a power transistor, a field effect transistor, etc., which are not limited herein.
The load unit 4 is configured as a light emitting unit LED 1.
The current source 5 comprises a first power tube Q 1 and a first amplifier EA 1, wherein the drain electrode of the first power tube Q 1 is connected with the load unit 4, and the source electrode is connected with the ground end GND through a first resistor R 1; the noninverting input terminal of the first amplifier EA 1 is connected to the external signal DIM through the second resistor R 2 and is connected to the ground terminal GND through the second capacitor C 2, and the second resistor R 2 and the second capacitor C 2 form a low-pass filter for smoothing the external signal DIM. The inverting input end of the first amplifier EA 1 is connected with the junction of the first power tube Q 1 and the first resistor R 1, and the output end is respectively connected with the grid electrode of the first power tube Q 1 and the control circuit 6.
Assuming that the external signal DIM is the voltage signal V DIM, the current I 1 flowing through the current source 5, i.e., the first power tube Q 1, stabilizes to V DIM/R1 in response to the voltage across the current source 5 being sufficient, whereas the current I 1 flowing through the current source 5, i.e., the first power tube Q 1, is less than V DIM/R1 in response to the voltage across the current source 5 being insufficient. Therefore, the operation state of the current source 5 can be judged by the voltage across the current source 5 or the current flowing through the current source 5.
The control circuit 6 includes a second power transistor Q 2 and a second amplifier EA 2, one end of the second power transistor Q 2 is connected to the control end of the discharge switch 32, i.e., the base b of the transistor SW 1, and the other end is connected to the ground GND. The noninverting input end of the second amplifier EA 2 is respectively connected with the output end of the first amplifier EA 1 and the control end of the first power tube Q 1, the inverting input end of the second amplifier EA 2 is connected with the second voltage source V 2, and the output end is connected with the control end of the second power tube Q 2.
In this embodiment, it is assumed that the external signal DIM is a voltage signal V DIM, the preset threshold is V DIM/R1, and the detection value of the current source 5 is a current I 1 flowing through the current source 5, i.e. the first power transistor Q 1.
In response to the current flowing through the current source 5, i.e., the current I 1 of the first power transistor Q 1 is greater than the preset threshold V DIM/R1, the output signal of the first amplifier EA 1 is smaller than the output signal of the second voltage source V 2, i.e., the signal of the non-inverting input terminal of the second amplifier EA 2 is smaller than the signal of the inverting input terminal, the second amplifier EA 2 controls the second power transistor Q 2 to be turned off, the second power transistor Q 2 controls the transistor SW 1 to be turned off, and the discharge switch 32 is turned off. At this time, the external power supply U S supplies power to the load unit 4, i.e., the LED 1, through the rectifying unit 1 and the first power tube Q 1, and the current value of the load unit 4, i.e., the current I 1 of the first power tube Q 1, is V DIM/R1.
In response to the current through the current source 5, i.e., the current I 1 of the first power transistor Q 1, being less than the preset threshold V DIM/R1, the current through the first resistor R 1 also drops, The voltage across the first resistor R 1 also drops, and when the voltage across the first resistor R 1 drops below V DIM, the output signal of the first amplifier EA 1 is greater than the output signal of the second voltage source V 2, That is, the signal at the non-inverting input terminal of the second amplifier EA 2 is greater than the signal at the inverting input terminal, the second amplifier EA 2 controls the second power transistor Q 2 to be turned on, and the second power transistor Q 2 controls the transistor SW 1 to be turned on. At this time, the energy storage capacitor C 1 supplies power to the load unit 4, i.e. the LED 1, via the triode SW 1 and the first power tube Q 1, The current value of the load unit 4, that is, the current I 1 of the first power transistor Q 1 is increased and tends to V DIM/R1. Here, the turn-on threshold of the first power transistor Q 1 is lower than the output signal of the second voltage source V 2.
By configuring the first amplifier EA 1 and the second amplifier EA 2 to have sufficient amplification, the current flowing through the LED 1, i.e., the current I 1 of the first power transistor Q 1, is approximately constant in both states, thereby realizing weak light-emitting flickering.
Since the storage capacitor C 1 is not discharged only when the voltage V S across the rectifying unit 1 is lower than the turn-on threshold of the load unit 4, the discharge time of the storage capacitor C 1 is shorter compared with the prior art scheme shown in fig. 2, and thus a smaller capacity capacitor can be used, improving the power factor.
[ Third embodiment ]
Fig. 5 is a schematic diagram of a driving circuit of a lighting device according to a third embodiment of the present utility model.
As shown in fig. 5, in a third embodiment of the present utility model, there is provided a driving circuit including a rectifying unit 1, an energy storage unit 2, a switching unit 3, a load unit 4, a current source 5, and a control circuit 6.
The control circuit 6 includes a third power transistor Q 3 and a third amplifier EA 3, one end of the third power transistor Q 3 is connected to the control end of the discharge switch 32, i.e., the base b of the transistor SW 1, and the other end is connected to the ground GND. The noninverting input end of the third amplifier EA 3 is connected with a third voltage source V 3, the inverting input end of the third amplifier EA 3 is connected with the junction of the load unit 4 and the first power tube Q 1, and the output end of the third amplifier EA 3 is connected with the control end of the third power tube Q 3.
In this embodiment, it is assumed that the external signal DIM is a voltage signal V DIM, the preset threshold is V 3, and the detected value of the current source 5 is the voltage value of both ends of the current source 5, that is, the drain voltage U 1 of the first power transistor Q1.
In response to the voltage value at two ends of the current source 5, that is, the drain voltage U 1 of the first power transistor Q1 is greater than the preset threshold V 3, the signal at the non-inverting input end of the third amplifier EA 3 is smaller than the signal at the inverting input end, the third amplifier EA 3 controls the third power transistor Q 3 to be turned off, the third power transistor Q 3 controls the triode SW 1 to be turned off, and the discharge switch 32 is turned off. At this time, the external power supply U S supplies power to the load unit 4, i.e., the LED 1, via the rectifying unit 1 and the first power tube Q 1.
In response to the voltage value at two ends of the current source 5, that is, the drain voltage U 1 of the first power transistor Q1 is smaller than the preset threshold V 3, the signal at the non-inverting input end of the third amplifier EA 3 is greater than the signal at the inverting input end, the third amplifier EA 3 controls the third power transistor Q 3 to be turned on, and the third power transistor Q 3 controls the transistor SW 1 to be turned on. At this time, the energy storage capacitor C 1 supplies power to the load unit 4, i.e. the LED 1, via the transistor SW 1 and the first power tube Q 1, so that the current value of the load unit 4, i.e. the current source current I 1, is increased, and the voltage value at two ends of the current source 5, i.e. the drain voltage U 1 of the first power tube Q1, is increased and approaches V 3.
The technical solution of the present utility model has been described so far with reference to the accompanying drawings. It will be readily appreciated by those skilled in the art that the scope of the utility model is obviously not limited to the specific embodiments described above. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present utility model, and such modifications and substitutions will fall within the scope of the present utility model.
Claims (8)
1. A driving circuit comprises a rectifying unit, an energy storage unit, a switch unit, a load unit, a current source and a control circuit, and is characterized in that,
The energy storage unit is connected with the switch unit in series, and the rectifying unit is connected with two ends of a series body formed by the energy storage unit and the switch unit in parallel;
The load unit is connected with the current source in series, and the rectifying unit is connected with two ends of a series body formed by the load unit and the current source in parallel;
One end of the control circuit is connected with the current source, the other end of the control circuit is connected with the control end of the switching unit, and the control circuit responds to the voltage values at two ends of the current source or the current value flowing through the current source being smaller than a preset threshold value to control the switching unit to discharge the energy storage unit.
2. The driving circuit according to claim 1, wherein the switching unit includes a charge switch and a discharge switch connected in parallel,
The charging switch is configured to: the charging switch is turned on in response to the voltage at the two ends of the rectifying unit being greater than the voltage at the two ends of the energy storage unit, otherwise the charging switch is turned off;
The discharge switch is configured to: and responding to the voltage values at two ends of the current source or the current value flowing through the current source is smaller than a preset threshold value, and switching on the discharge switch, otherwise, switching off the discharge switch.
3. The driving circuit according to claim 2, wherein,
The charge switch is configured as a diode.
4. The drive circuit of claim 2, wherein the current source is configured as a variable current source controlled by an external signal.
5. The driving circuit of claim 4, wherein the current source comprises a first power tube having one end connected to the load unit and the other end connected to ground through a first resistor.
6. The driving circuit according to claim 5, wherein the control circuit comprises
One end of the second power tube is connected with the control end of the discharge switch, and the other end of the second power tube is connected with the grounding end;
And the second amplifier is used for controlling the second power tube to be conducted in response to the fact that the current of the first power tube is lower than a preset threshold value.
7. The driving circuit according to claim 5, wherein the control circuit comprises
One end of the third power tube is connected with the control end of the discharge switch, and the other end of the third power tube is connected with the grounding end;
And the third amplifier is used for controlling the third power tube to be conducted in response to the drain voltage of the first power tube being lower than a preset threshold value.
8. A lighting device comprising the drive circuit of any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202323095524.7U CN221202358U (en) | 2023-11-15 | 2023-11-15 | Driving circuit and lighting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202323095524.7U CN221202358U (en) | 2023-11-15 | 2023-11-15 | Driving circuit and lighting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN221202358U true CN221202358U (en) | 2024-06-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202323095524.7U Active CN221202358U (en) | 2023-11-15 | 2023-11-15 | Driving circuit and lighting device |
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| CN (1) | CN221202358U (en) |
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2023
- 2023-11-15 CN CN202323095524.7U patent/CN221202358U/en active Active
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