A non-isolated shutdown low standby power consumption dimming circuit

Abstract

The embodiment of the present invention discloses a non-isolated shutdown low standby power consumption dimming circuit, which relates to the field of LED dimming technology. The dimming circuit includes a dimming unit, a relay control unit, a relay unit, a power output unit and a power supply unit; the dimming unit is connected to the relay control unit, the relay control unit is respectively connected to the relay unit and the power supply unit, the relay unit is connected to the power output unit, the power output unit is connected to the LED lamp, and the power supply unit is connected to the IC chip. When the duty cycle of the PWM signal received by the dimming unit is less than the preset duty cycle threshold, the dimming unit outputs a high level signal to the relay control unit; when receiving the high level signal output by the dimming unit, the relay control unit controls the relay unit to cut off the power output unit to the LED lamp, and controls the power supply unit to stop supplying power to the IC chip. In this way, the LED lamp can be turned off, and the power supply of the IC chip can be cut off at the same time to achieve the purpose of reducing the standby power consumption.

Description

Technical Field

[0001] The invention relates to the technical field of LED dimming, and in particular to a non-isolated shutdown low standby power consumption dimming circuit. Background Art

[0002] In the traditional non-isolated topology, due to the parasitic capacitance between the lamp bead and the lamp board, a loop is formed from the live wire to the PFC part, then to the BUCK part, then to the lamp bead, the parasitic capacitance, and finally to the lamp and back to the ground. In this way, the lamp is dim and cannot be turned off.

[0003] Meanwhile, when the traditional circuit is in standby mode, the standby power consumption exceeds 0.5W, which does not meet the requirements of ERP (Enterprise Resource Planning) instructions. Summary of the invention

[0004] The embodiment of the present invention provides a non-isolated shutdown low standby power consumption dimming circuit, aiming to solve the problem that the existing non-isolated topology dimming cannot turn off the LED lamp and has high standby power consumption.

[0005] In order to solve the above problems, an embodiment of the present invention proposes a non-isolated shutdown low standby power consumption dimming circuit, wherein the non-isolated shutdown low standby power consumption dimming circuit comprises a dimming unit, a relay control unit, a relay unit, a power output unit and a power supply unit; the dimming unit is connected to the relay control unit, the relay control unit is respectively connected to the relay unit and the power supply unit, the relay unit is connected to the power output unit, the power output unit is connected to the LED lamp, and the power supply unit is connected to the IC chip;

[0006] Among them, when the duty cycle of the PWM signal received by the dimming unit is less than a preset duty cycle threshold, the dimming unit outputs a high-level signal to the relay control unit; when receiving the high-level signal output by the dimming unit, the relay control unit controls the relay unit to cut off the power output of the power output unit to the LED lamp, and controls the power supply unit to stop supplying power to the IC chip.

[0007] A further technical solution is that the dimming unit includes a first resistor, a second resistor, a first capacitor and an operational amplifier, the first resistor and the second resistor are connected in series, the second resistor is connected to the negative input terminal of the operational amplifier, and the first capacitor is connected to the first resistor and grounded.

[0008] Its further technical solution is that the non-isolated shutdown low standby power consumption dimming circuit also includes a hysteresis unit, the hysteresis unit includes a third resistor and a fourth resistor, the third resistor is connected to the positive input terminal of the operational amplifier, and the fourth resistor is respectively connected to the positive input terminal and the output terminal of the operational amplifier.

[0009] A further technical solution is that the relay control unit comprises a first MOS tube, a gate of the first MOS tube is connected to the output end of the operational amplifier, a drain of the first MOS tube is connected to the relay unit, and a source of the first MOS tube is grounded.

[0010] A further technical solution is that the gate of the first MOS tube is connected to the output end of the operational amplifier through a fifth resistor, and the gate of the first MOS tube is grounded through a sixth resistor and a second capacitor.

[0011] A further technical solution is that the relay unit comprises a relay, and a control end of the relay is connected to the drain of the first MOS tube.

[0012] A further technical solution is that the power output unit includes a positive power line and a negative power line, and the relay includes two controlled switches, which are respectively arranged on the positive power line and the negative power line.

[0013] Its further technical solution is that the power supply unit includes a second MOS tube and a transistor, the drain of the first MOS tube is connected to the gate of the second MOS tube, the drain of the second MOS tube is connected to the base of the transistor, and the source of the second MOS tube is grounded; the emitter of the transistor is connected to the power supply end, and the collector of the transistor is connected to the IC chip.

[0014] A further technical solution is that the power supply end is connected to the gate of the second MOS tube through the seventh resistor, and the gate of the second MOS tube is grounded through the eighth resistor and the third capacitor respectively.

[0015] A further technical solution is that the power supply end is connected to the base of the transistor through a ninth resistor, and the base of the transistor is connected to the drain of the second MOS tube through a tenth resistor.

[0016] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include:

[0017] When the duty cycle of the PWM signal received by the dimming unit is less than the preset duty cycle threshold, the dimming unit outputs a high level signal to the relay control unit; when receiving the high level signal output by the dimming unit, the relay control unit controls the relay unit to cut off the power output of the power output unit to the LED lamp, and controls the power supply unit to stop supplying power to the IC chip. In this way, the LED lamp can be turned off, and the power supply of the IC chip can be cut off at the same time to achieve the purpose of reducing standby power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0019] Figure 1 A principle block diagram of a non-isolated shutdown low standby power consumption dimming circuit proposed in an embodiment of the present invention;

[0020] Figure 2 The present invention provides a circuit diagram of a non-isolated shutdown low standby power consumption dimming circuit according to an embodiment of the present invention.

[0021] Reference numerals

[0022] A dimming unit 100 , a relay control unit 200 , a relay unit 300 , a power output unit 400 , a power supply unit 500 , an LED lamp 600 , an IC chip 700 , and a hysteresis unit 800 . DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0025] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0026] See also Figure 1-Figure 2The embodiment of the present invention provides a non-isolated shutdown low standby power consumption dimming circuit. As can be seen from the figure, the non-isolated shutdown low standby power consumption dimming circuit includes a dimming unit 100, a relay control unit 200, a relay unit 300, a power output unit 400 and a power supply unit 500. The dimming unit 100 is connected to the relay control unit 200, the relay control unit 200 is respectively connected to the relay unit 300 and the power supply unit 500, the relay unit 300 is connected to the power output unit 400, the power output unit 400 is connected to the LED lamp 600, and the power supply unit 500 is connected to the IC chip 700.

[0027] When the duty cycle of the PWM signal received by the dimming unit 100 is less than the preset duty cycle threshold, the dimming unit 100 outputs a high level signal to the relay control unit 200; when receiving the high level signal output by the dimming unit 100, the relay control unit 200 controls the relay unit 300 to cut off the power output of the power output unit 400 to the LED lamp 600, and controls the power supply unit 500 to stop supplying power to the IC chip 700. In this way, the LED lamp 600 can be turned off, and the power supply of the IC chip 700 can be cut off at the same time to achieve the purpose of reducing the standby power consumption.

[0028] Accordingly, when the duty cycle of the PWM signal received by the dimming unit 100 is greater than a preset threshold, the dimming unit 100 outputs a low-level signal to the relay control unit 200; when receiving the low-level signal output by the dimming unit 100, the relay control unit 200 controls the relay unit 300 to conduct the power output unit 400 to the LED lamp 600, and controls the power supply unit 500 to supply power to the IC chip 700. In this way, the LED lamp 600 can be turned on and power can be supplied to the IC chip 700 at the same time.

[0029] Further, the dimming unit 100 includes a first resistor R305, a second resistor R306, a first capacitor C307 and an operational amplifier AS321, the first resistor R305 and the second resistor R306 are connected in series, the second resistor R306 is connected to the negative input terminal of the operational amplifier AS321 (i.e., pin 3 of the operational amplifier AS321), the first capacitor C307 is connected to the first resistor R305 and is grounded. A PWM signal source is connected to the first resistor R305 to output a PWM signal.

[0030] Furthermore, the non-isolated shutdown low standby power consumption dimming circuit further includes a hysteresis unit 800, which includes a third resistor R310 and a fourth resistor R316, wherein the third resistor R310 is connected to the positive input terminal of the operational amplifier AS321 (i.e., pin 1 of the operational amplifier AS321), and the fourth resistor R316 is connected to the positive input terminal of the operational amplifier AS321 and the output terminal of the operational amplifier AS321 (i.e., pin 4 of the operational amplifier AS321). The positive input terminal of the operational amplifier AS321 is used to receive a reference signal.

[0031] Furthermore, the relay control unit 200 includes a first MOS transistor Q301, a gate of the first MOS transistor Q301 is connected to the output end of the operational amplifier AS321, a drain of the first MOS transistor Q301 is connected to the relay unit 300, and a source of the first MOS transistor Q301 is grounded.

[0032] Furthermore, the gate of the first MOS transistor Q301 is connected to the output end of the operational amplifier AS321 through the fifth resistor R307, and the gate of the first MOS transistor Q301 is grounded through the sixth resistor R308 and the second capacitor C305.

[0033] Further, the relay unit 300 includes a relay K1, and the control end of the relay K1 (pin 1 of the relay K1) is connected to the drain of the first MOS tube Q301. The power output unit 400 includes a positive power line and a negative power line, and the relay includes two controlled switches, and the two controlled switches are respectively arranged on the positive power line and the negative power line. The positive power line and the negative power line are respectively connected to the positive pole LED+ and the negative pole LED- of the LED lamp. The positive power line can be specifically a live wire, and the negative power line can be specifically a neutral wire.

[0034] Furthermore, the power supply unit 500 includes a second MOS tube Q302 and a transistor Q103, the drain of the first MOS tube Q301 is connected to the gate of the second MOS tube Q302, the drain of the second MOS tube Q302 is connected to the base of the transistor Q103, and the source of the second MOS tube Q302 is grounded; the emitter of the transistor Q103 is connected to the power supply terminal PVCC, and the collector of the transistor is connected to the IC chip 700 (specifically connected to the power supply interface VCC of the IC chip 700).

[0035] Furthermore, the power supply terminal PVCC is connected to the gate of the second MOS transistor Q302 through the seventh resistor R114, and the gate of the second MOS transistor Q302 is grounded through the eighth resistor R121 and the third capacitor C110.

[0036] Furthermore, the power supply terminal PVCC is connected to the base of the transistor Q103 through the ninth resistor R104, and the base of the transistor Q103 is connected to the drain of the second MOS transistor Q302 through the tenth resistor R122.

[0037] The working principle of the present invention is as follows:

[0038] When the duty cycle of the PWM signal gradually decreases from large to small, the PWM signal is converted into a DC signal after RC filtering through the first resistor R305 and the first capacitor C307. The corresponding DC signal gradually decreases, and the negative input terminal of the operational amplifier AS321 gradually changes from being greater than the reference voltage VREF to being less than the reference voltage VREF. The output of the output terminal of the operational amplifier AS321 gradually changes from the original low level to the high level, and the gate of the first MOS tube Q301 gradually changes from the low level to the high level, and the first MOS tube Q301 gradually changes from the original cut-off state to the on state. , pin 1 of relay K1 is pulled low, the voltage between pin 12 and pin 1 of relay K1 exceeds the turn-on voltage of relay K1, relay K1 is actuated, the normally closed switch is disconnected, and the purpose of output shutoff is achieved; at the same time, since the first MOS tube Q301 changes from the original cut-off state to the on state, the gate of the second MOS tube Q302 changes from the original high level to the low level, the second MOS tube Q302 changes from the original on state to the cut-off state, and the triode Q103 changes from the original on state to the cut-off state, resulting in the power supply of the IC chip being cut off, thereby achieving the purpose of reducing the standby power consumption.

[0039] When the duty cycle of the PWM signal gradually increases from small, the PWM signal is converted into a DC signal after RC filtering by the first resistor R305 and the first capacitor C307. The corresponding DC signal gradually increases, and the negative input terminal of the operational amplifier AS321 gradually changes from less than the reference voltage VREF to greater than the reference voltage VREF. The output of the output terminal of the operational amplifier AS321 gradually changes from the original high level to the low level, and the gate of the first MOS tube Q301 gradually changes from the high level to the low level. The first MOS tube Q301 gradually changes from the original on state to the off state. The voltage between the pin 12 and the pin 1 of the relay K1 does not exceed the turn-on voltage of the relay K1, and the relay K1 changes from the original off state to the normally closed state. At the same time, because the first MOS tube Q301 changes from the original on state to the off state, the gate of the second MOS tube Q302 changes from the original low level to the high level, the first MOS tube Q302 changes from the original off state to the on state, and the transistor Q103 changes from the original off state to the on state. The power supply terminal PVCC supplies power to the IC chip normally.

[0040] A hysteresis circuit is further introduced to solve the problem of flashing caused by repeated actions of the relay K1. The reference voltage VREF determines the size of the turn-off point, and the fourth resistor R316 and the third resistor R310 determine the size of the hysteresis.

[0041] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0042] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0043] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A non-isolated shutdown low standby power consumption dimming circuit, characterized in that: It includes a dimming unit, a relay control unit, a relay unit, a power output unit and a power supply unit; the dimming unit is connected to the relay control unit, the relay control unit is connected to the relay unit and the power supply unit respectively, the relay unit is connected to the power output unit, the power output unit is connected to the LED lamp, and the power supply unit is connected to the IC chip; Wherein, when the duty cycle of the PWM signal received by the dimming unit is less than a preset duty cycle threshold, the dimming unit outputs a high level signal to the relay control unit; when receiving the high level signal output by the dimming unit, the relay control unit controls the relay unit to cut off the power output of the power output unit to the LED lamp, and controls the power supply unit to stop supplying power to the IC chip; The dimming unit includes a first resistor, a second resistor, a first capacitor and an operational amplifier, the first resistor and the second resistor are connected in series, the second resistor is connected to the negative input terminal of the operational amplifier, and the first capacitor is connected to the first resistor and is grounded; The non-isolated shutdown low standby power consumption dimming circuit also includes a hysteresis unit, the hysteresis unit includes a third resistor and a fourth resistor, the third resistor is connected to the positive input terminal of the operational amplifier, and the fourth resistor is respectively connected to the positive input terminal of the operational amplifier and the output terminal of the operational amplifier; The relay control unit comprises a first MOS tube, a gate of the first MOS tube is connected to the output end of the operational amplifier, a drain of the first MOS tube is connected to the relay unit, and a source of the first MOS tube is grounded; The gate of the first MOS tube is connected to the output end of the operational amplifier through the fifth resistor, and the gate of the first MOS tube is grounded through the sixth resistor and the second capacitor respectively; The relay unit comprises a relay, wherein a control end of the relay is connected to a drain of the first MOS tube; The power output unit includes a positive power line and a negative power line, and the relay includes two controlled switches, which are respectively arranged on the positive power line and the negative power line; The power supply unit includes a second MOS tube and a triode, the drain of the first MOS tube is connected to the gate of the second MOS tube, the drain of the second MOS tube is connected to the base of the triode, and the source of the second MOS tube is grounded; the emitter of the triode is connected to the power supply end, and the collector of the triode is connected to the IC chip; The power supply end is connected to the gate of the second MOS tube through the seventh resistor, and the gate of the second MOS tube is grounded through the eighth resistor and the third capacitor respectively; The power supply end is connected to the base of the transistor through the ninth resistor, and the base of the transistor is connected to the drain of the second MOS transistor through the tenth resistor.

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