POWER SUPPLY CIRCUIT, DALI MODULE, LIGHTING EQUIPMENT AND CONTROLLING METHOD
TECHNICAL FIELD
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Embodiments of the present disclosure generally relate to the field of lighting, and more particularly, to a power supply circuit, a DALI (digital addressable lighting interface) module, a lighting equipment and a controlling method.
BACKGROUND
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This section introduces aspects that may facilitate better understanding of the present disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
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DALI (digital addressable lighting interface) is a data transmission protocol that defines a digital communication method between lighting devices and controllers. DALI system is an intelligent lighting control system, not only can be used for lighting control in a room, but also can be connected with the building management system (BMS) . The most important feature of the DALI system is that each lighting device has an independent address, and the lighting device can be accurately dimmed through the DALI system. The lighting device is LED (Light Emitting Diode) for example.
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DALI circuit provides DALI communication bus, which may include data bus and power bus. Lighting devices and peripheral devices can be connected to the communication bus.
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SUMMARY
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DALI circuit with a 50mA constant current source can drive more peripheral devices on DALI communication bus, so as to make the DALI lighting system much powerful. The peripheral devices may be dimmers, sensors, controllers, security device, etc.
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The DALI circuit may include a NTC (Negative Temperature Coefficient) resistor, which is used to compensate the temperature drift of PN junction in the DALI circuit, so that the constant current can be obtained during the DALI circuit is working.
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The inventor found that: in the DALI circuit, the NTC resistor is always hard to compensate the temperature drift of PN junction, therefore the accuracy of current outputted by the DALI circuit is low.
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In general, embodiments of the present disclosure provide a power supply circuit, a DALI (digital addressable lighting interface) circuit, a lighting equipment and a controlling method. In the embodiments, a current regulation controller is provided in the power supply circuit, when a current of the second output port (DA-) is larger than a preset value, the current regulation controller will turn down a current flowing through the regulating transistor (Q161) . Therefore, current with higher accuracy can be obtained.
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In a first aspect, there is provided a power supply circuit, includes:
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a power source circuit (100) ;
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a regulating transistor (Q161) , configured to be connected between the power source circuit and a first output port (DA+) ;
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a first controller (U160) , configured to control the regulation transistor (Q161) to be turned on or off; and
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a current regulation controller (A) , configured to be connected between the power source circuit and a second output port (DA-) , the current regulation controller (A) being further connected between the regulating transistor (Q161) and the first controller (U160) ,
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when a current of the second output port (DA-) being larger than a preset value, the current regulation controller (A) turning down a current flowing through the regulating transistor (Q161) .
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According to one embodiment, the current regulation controller (A) comprises:
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a first resistor (R162) , configured to be connected between a controlling terminal of the regulating transistor (Q161) and the first controller (U160) ;
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a first transistor (Q160) , configured to be connected between the power source circuit and the controlling terminal of the regulating transistor (Q161) ;
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a voltage reference circuit (U1) ;
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a second resistor (R164) ; and
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a third resistor (R170) ,
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the voltage reference circuit (U1) , the second resistor (R164) and the third resistor (R170) are connected in series between the power source circuit and a ground terminal,
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a controlling terminal of the first transistor (Q160) is connected to the connecting node of the second resistor (R164) and the third resistor (R170) ,
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an anode of the voltage reference circuit (U1) is connected to the ground terminal,
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a cathode of the voltage reference circuit (U1) is connected to the third resistor (R170) ,
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a reference terminal of the voltage reference circuit (U1) receives a voltage corresponding to the current of the second output port (DA-) .
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According to one embodiment, the current regulation controller (A) further comprises:
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a fourth resistor (R174) and a first capacitor (C161) ,
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the fourth resistor (R174) and the first capacitor (C161) are connected in serial between the power source circuit and the reference terminal of the voltage reference circuit (U1) .
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According to one embodiment, the power supply circuit further comprises:
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a current stage selection circuit (B) , configured to be connected between the first output port (DA+) and the second output port (DA-) ,
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the current stage selection circuit (B) comprises:
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a fifth resistor (R171) ;
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a sixth resistor (R168) ; and
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a second transistor (Q162) ,
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the fifth resistor (R171) and the sixth resistor (R168) are connected in serial between the second output port (DA-) and the ground terminal,
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the second transistor (Q162) and the sixth resistor (R168) are connected in parallel.
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According to one embodiment, when the first output port (DA+) and the second output port (DA-) are short connected, the second transistor (Q162) is turned off.
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According to one embodiment, the current stage selection circuit (B) further comprises:
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a seventh resistor (R161) ;
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an eighth resistor (R163) ; and
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a ninth resistor (R172) ,
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the seventh resistor (R161) , the eighth resistor (R163) and the ninth resistor (R172) are connected in serial between the first output port (DA+) and the ground terminal,
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a controlling terminal of the second transistor (Q162) is connected with a connecting node of the eighth resistor (R163) and the ninth resistor (R172) .
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In a second aspect, there is provided a digital addressable lighting interface (DALI) module, comprises a DALI interface circuit and the power supply circuit according to the first aspect, the power supply circuit providing power to the DALI interface circuit and a peripheral device on DALI communication bus.
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In a third aspect, there is provided a lighting equipment, comprising a lighting device, a digital addressable lighting interface (DALI) module according to the second aspect and a driver, the DALI circuit controls the driver to drive the lighting equipment.
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In a fourth aspect, there is provided a controlling method of a power supply circuit according to the first aspect, the controlling method includes:
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when a current of the second output port (DA-) being larger than a preset value, the current regulation controller (A) turning down a current flowing through the regulating transistor (Q161) .
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According to one embodiment, the method further comprises:
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when the first output port (DA+) and the second output port (DA-) are short connected, the second transistor (Q162) is turned off.
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According to various embodiments of the present disclosure, a current regulation controller is provided in the power supply circuit, when a current of the second output port (DA-) is larger than a preset value, the current regulation controller will turn down a current flowing through the regulating transistor (Q161) . Therefore, current with higher accuracy can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
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The above and other aspects, features, and benefits of various embodiments of the disclosure will become more fully apparent, by way of example, from the following detailed description with reference to the accompanying drawings, in which like reference numerals or letters are used to designate like or equivalent elements. The drawings are illustrated for facilitating better understanding of the embodiments of the disclosure and not necessarily drawn to scale, in which:
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Fig. 1 is a diagram of a power supply circuit in accordance with the first aspect of embodiments of the present disclosure
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Fig. 2 is a diagram of the current outputted by the power supply circuit before and after DALI interface shorts
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Fig. 3 is a flowchart of a controlling method of the power supply circuit 10
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Fig. 4 is a diagram of a DALI module of the third aspect of embodiment;
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Fig. 5 is a diagram of a lighting equipment of the fourth aspect of embodiment.
DETAILED DESCRIPTION
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The present disclosure will now be discussed with reference to several example embodiments. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the present disclosure.
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As used herein, the terms “first” and “second” refer to different elements. The singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises, ” “comprising, ” “has, ” “having, ” “includes” and/or “including” as used herein, specify the presence of stated features, elements, and/or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” Other definitions, explicit and implicit, may be included below.
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First aspect of embodiments
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A power supply circuit is provided in a first embodiment.
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Fig. 1 is a diagram of a power supply circuit in accordance with an embodiment of the present disclosure.
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As shown in Fig. 1, a power supply circuit 10 includes a power source circuit 100, a regulating transistor Q161, a first controller U160 and a current regulation controller A.
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The power source circuit 100 may provide direct current (DC) power. For example, the power source circuit 100 may include an inductor L60-a, an diode D160 and two capacitor C 160, C66. The power source circuit 100 may convert alternative current (AC) power into DC power.
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The regulating transistor Q161 is configured to be connected between the power source circuit 100 and a first output port DA+. For example, the regulating transistor Q161 is a PNP bipolar transistor with its emitter is connected to a resistor R167, and its collector is connected to an anode of a diode D161. The resistor R167 is connected between a cathode of diode D160 and the emitter of the regulating transistor Q161. A cathode of diode D161 is connected to the first output port DA+.
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The first controller U160 is configured to control the regulation transistor Q161 to be turned on or off. For example, the first controller U160 is an optical coupler (OC) . A first resistor R162 is connected between a controlling terminal (for example, a base) of the regulating transistor Q161 and the first controller U160. When an “enable” signal is provided to a resistor R100, a transistor Q102 conducts, and the first controller U160 pulls down the voltage of the controlling terminal of the regulating transistor Q161, so as to turn on the regulating transistor Q161.
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The current regulation controller A is configured to be connected between the power source circuit 100 and a second output port DA-. The current regulation controller A is further connected between the regulating transistor Q161 and the first controller U160.
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In one embodiment, when a current of the second output port DA-is larger than a preset value, the current regulation controller A turns down a current flowing through the regulating transistor Q161. Therefore a feedback control is achieved, and current with higher accuracy can be obtained.
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As shown in Fig. 1, the current regulation controller A includes: the first resistor R162, a first transistor Q160, a voltage reference circuit U1, a second resistor R164 and a third resistor 170.
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As above mentioned, the first resistor R162 is configured to be connected between the controlling terminal of the regulating transistor Q161 and the first controller U160.
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The first transistor Q160 is configured to be connected between the power source circuit and the controlling terminal of the regulating transistor Q161. The first transistor Q160 may be a PNP bipolar transistor. An emitter of the first transistor Q160 is connected to the cathode of the diode D160 via a resistor R173.
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The voltage reference circuit U1, the second resistor R164 and the third resistor R170 are connected in series between the power source circuit 100 and a ground terminal (GND) .
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A controlling terminal (for example, the base) of the first transistor Q160 is connected to the connecting node of the second resistor R164 and the third resistor R170.
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An anode (1) of the voltage reference circuit U1 is connected to the ground terminal (GND_DaliPS) , a cathode (2) of the voltage reference circuit U1 is connected to the third resistor R170, and a reference terminal (3) of the voltage reference circuit U1 receives a voltage corresponding to the current of the second output port DA-. The voltage reference circuit U1 may be TL431.
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The current regulation controller A further includes: a fourth resistor R174 and a first capacitor C161. The fourth resistor R174 and the first capacitor C161 are connected in serial between the power source circuit and the reference terminal of the voltage reference circuit U1.
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When the reference terminal (3) of the voltage reference circuit U1 receives a voltage higher than a threshold (for example, the threshold of voltage is corresponding to the preset value of current) , the voltage reference circuit U1 is turned on, a current flows through the resistor R173, the second resistor R164, the third resistor R170, the voltage reference circuit U1 to the ground terminal. A voltage drop on the second resistor R164 turns on the first transistor Q160. Besides, the voltage received by the reference terminal (3) of the voltage reference circuit U1 is applied to the emitter of the first transistor Q160. Conducting of the first transistor Q160 will increase current flows through the first resistor R162, thus to pull up the voltage of the controlling terminal of the regulating transistor Q161 and conducting current flowing through the regulating transistor Q161 decreases. Therefore, the conducting current can remain a constant value, the accuracy of 1%is easy to realize.
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As shown in Fig. 1, the power supply circuit 10 further includes a current stage selection circuit B. The current stage selection circuit B is configured to be connected between the first output port DA+ and the second output port DA-.
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For example, the current stage selection circuit B may include a fifth resistor R171, a sixth resistor R168 and a second transistor Q162.
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The fifth resistor R171 and the sixth resistor R168 are connected in serial between the second output port DA-and the ground terminal (GND_DAliPS) . The second transistor Q162 and the sixth resistor R168 are connected in parallel. For example, the second transistor Q162 may be a MOS FET, such as 2N7002, a source of the second transistor Q162is connected to the ground terminal, a drain of the second transistor Q162 is connected to a connecting node between the fifth resistor R171 and the sixth resistor R168. Resistance of the sixth resistor R168 maybe 2 times higher than resistance of the fifth resistor R171, for example, resistance of the sixth resistor R168 may be 150Ω, resistance of the fifth resistor R171 may be 50Ω.
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When the first output port DA+ and the second output port DA-are not short connected, the second transistor Q162 is turned on, and current flows through the fifth resistor R171 from the second output port DA-to the ground terminal (GND_DAliPS) , for example, the current is 50mA. When the first output port DA+ and the second output port DA-are short connected (for example, DALI interface shorts) , the second transistor Q162 is turned off, and current flows through the fifth resistor R171 and the sixth resistor R168 from the second output port DA-to the ground terminal (GND_DAliPS) , and current flowing from the second output port DA-to the ground terminal (GND_DAliPS) decreases, for example, the current decreases to 10mA～11mA.
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In at least one embodiment, as shown in Fig. 1, the current stage selection circuit B further comprises: a seventh resistor R161, an eighth resistor R163 and a ninth resistor R172. The seventh resistor R161, the eighth resistor R163 and the ninth resistor R172 are connected in serial between the first output port DA+ and the ground terminal. A controlling terminal (for example, a gate) of the second transistor Q162 is connected with a connecting node of the eighth resistor R163 and the ninth resistor R172.
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The current stage selection circuit B may further comprise: a diode D163 and a Zenar diode Z161. A cathode of the diode D163 and a cathode of the Zenar diode Z161 is connected with each other, an anode of the diode D163 is connected to the anode of the diode D161, and an anode of the Zenar diode Z161 is connected to the anode of the seventh resistor R161.
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In at least one embodiment, when the first output port DA+ and the second output port DA-are not short connected, the Zenar diode Z161 is reversely broken-down, a current flows through the seventh resistor R161, the eighth resistor R163 and the ninth resistor R172. The voltage drop on the ninth resistor R172 provides Vgs to turn on the second transistor Q162, and the current flows through the fifth resistor R171 from the second output port DA-to the ground terminal (GND_DAliPS) . In this case, the fifth resistor R171is working as current sensing resistor.
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In at least one embodiment, when the first output port DA+ and the second output port DA-are short connected, there is no current flowing through the seventh resistor R161, the eighth resistor R163 and the ninth resistor R172, thus the second transistor Q162 is turned off. The current flows through the fifth resistor R171 and the sixth resistor R168 from the second output port DA-to the ground terminal (GND_DAliPS) . In this case, the fifth resistor R171 and the sixth resistor R168 are working as current sensing resistors.
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Fig. 2 is a diagram of the current outputted by the power supply circuit before and after DALI interface shorts. In Fig. 2, the horizontal axis represents time, the vertical axis represents value of current. As shown in Fig. 2, before DALI interface shorts, the current is still 50mA. During a delay from the DALI interface shorts, the current decreases to 11mA linearly. Finally, the current is stable at 11mA.
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According to the first aspect of embodiments, by employing the current regulation controller A, accuracy of current outputted from the power supply circuit 10 is improved.
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According to the first aspect of embodiments, by using the current stage selection circuit B, when the first output port DA+ and the second output port DA-are short connected, the current of power supply circuit 10 decreases, thus energy is saved when DALI interface shorts .
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Second aspect of embodiments
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A controlling method of a power supply circuit. The power supply circuit is provided in the first aspect of embodiments. The same contents as those in the first aspect of embodiments are omitted.
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Fig. 3 shows a flowchart of a controlling method of the power supply circuit 10.
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As shown in Fig. 3, the method 30 includes:
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Block 31: when a current of the second output port (DA-) being larger than a preset value, the current regulation controller (A) turning down a current flowing through the regulating transistor (Q161) .
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As shown in Fig. 3, the method 30 further includes:
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Block 32: when the first output port (DA+) and the second output port (DA-) are short connected, the second transistor (Q162) is turned off.
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According to the second aspect of embodiments, accuracy of current outputted from the power supply circuit 10 is improved, and energy is saved when DALI interface shorts.
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Third aspect of embodiments
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A digital addressable lighting interface (DALI) module is provided in an embodiment.
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Fig. 4 is a diagram of a DALI module of the third aspect of embodiments. As shown in Fig. 4, a DALI module 40 includes a power supply circuit 10 and a DALI interface circuit 30. The power supply circuit 10 is described in the first aspect of embodiments.
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The power supply circuit 10 provides power to the DALI interface circuit 30 and to a peripheral device on DALI communication bus.
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The peripheral devices may be dimmers, sensors, controllers, security device, etc.
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The diagram of the DALI interface circuit 30 is shown in Fig. 4. As shown in Fig. 4, the DALI interface circuit 30 may include resistors R142, R143, R145, R147, R148, R149, R150; capacitors C03, C142, C140, C144, C146, C147, C148; transistors Q140, Q141, Q142, Q143, Q145; Zenar diode Z140; diode bridge D140; optical couplers U140 and U141.
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Fourth aspect of embodiments
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A lighting equipment is provided in an embodiment.
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Fig. 5 is a diagram of the lighting equipment. As shown in Fig, 5, the lighting equipment 50 includes a lighting device (not shown) , a digital addressable lighting interface (DALI) module 40, and a driver 60. The DALI module 40 is provided according to the third aspect of embodiments. For example, the DALI module 40 includes a power supply circuit 10 and a DALI interface circuit 30.
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The driver 60 may supply direct current (DC) power to the lighting device. The driver 60 may be an LED driver, the lighting device may be an LED device. The DALI interface circuit 30 controls the driver 60 to drive the lighting equipment.
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An output power, output voltage or output current of the lighting device may be changed from a minimum to maximum value according to dimming signal, e.g. 1-10V, which is received via DALI (Digital Addressable Lighting Interface) , NFC (Near Field Communication) , Bluetooth etc.. Preferably the DC-DC-converter supplying the lighting device will change its output parameters (current and/or voltage) depending on the dimming signal.
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Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.
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Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.