Boost control circuit for auxiliary light source of LED street lamp

Abstract

The utility model discloses an LED street lamp auxiliary light source boost control circuit, which comprises a control power switch N531, a boost circuit and a current-limiting voltage-stabilizing circuit, a fifth pin of the control power switch N531 is connected with a resistor Re3, the resistor Re3 is connected to a single-chip microcomputer pwm output port, the fifth pin of the control power switch N531 is further connected with a triode VNe1, and a base electrode of the triode VNe1 receives Imax out signals; the third pin of the control power switch N531 is an output end connected to the input end of the boost circuit, one path of the boost circuit is connected to the auxiliary light source bonding pad, and the other path of the boost circuit is connected to the current-limiting voltage-stabilizing circuit. According to the utility model, a boost circuit switch is controlled by utilizing a pwm signal of the single-chip microcomputer, boost is realized by utilizing the characteristics of an inductor, the boost operation of the auxiliary light source is driven, the boost operation is separated from the driving of the main light source, short circuit is prevented, and the whole LED control system is more stable in operation.

Description

Technical Field

[0001] The utility model relates to an LED street lamp, in particular to a boost control circuit for an auxiliary light source of an LED street lamp. Background Art

[0002] Some LED street lights are equipped with a secondary light source for the main light source. Since the main and secondary light sources have different lighting brightness and require different voltages, the secondary light source cannot be directly driven by the main light source. A boost control circuit for the secondary light source needs to be designed. Utility Model Content

[0003] In order to solve the defects of the above-mentioned prior art, the utility model provides a boost control circuit for the auxiliary light source of an LED street lamp. The utility model uses the PWM signal of the single-chip microcomputer to control the boost circuit switch, and uses the characteristics of the inductor to achieve boost, which is used to drive the auxiliary light source to boost the voltage. It is separated from the drive of the main light source to prevent short circuit, and the entire LED control system runs more stably.

[0004] To achieve the above technical objectives, the present invention adopts the following technical solutions: a boost control circuit for an auxiliary light source of an LED street lamp, comprising a control power switch N531, a boost circuit, and a current limiting and voltage stabilizing circuit, wherein pin 5 of the control power switch N531 is connected to a resistor Re3, which is connected to a PWM output port of a single-chip microcomputer; pin 5 of the control power switch N531 is also connected to a transistor VNe1, and the base of the transistor VNe1 receives an Imax out signal;

[0005] Pin 3 of the control power switch N531 is an output end connected to the input end of the boost circuit. One path of the boost circuit is connected to the auxiliary light source pad, and the other path is connected to the current limiting and voltage stabilizing circuit.

[0006] Pin 5 of the control power switch N531 is also connected to the collector of the transistor VNe1, the emitter of the transistor VNe1 is connected to the negative electrode of the battery, pin 1 of the control power switch N531 is connected to capacitor Ce5, capacitor Ce5 is connected to the negative electrode of the battery, and pin 1 is connected to Vdd 12V; pin 3 of the control power switch N531 is connected to diode De1 on one side and to the base of the transistor VPe1 on the other side, diode De1 is connected to resistor Re1, resistor Re1 is connected to the emitter of the transistor VPe1, and the collector of the transistor VPe1 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to resistor Re7, and resistor Re7 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to the input end of the boost circuit.

[0007] The boost circuit includes a MOS transistor QNe1, the gate of which is connected to the emitter of the triode VPe1 in one path and to the diode Dez1 in the other path, which is connected to the negative electrode of the battery; the source of the MOS transistor QNe1 is connected to the negative electrode of the battery; the drain of the MOS transistor QNe1 is divided into five paths, the first path is connected to the diode TVSe1, which is connected to the negative electrode of the battery; the second path is connected to the capacitor Ce1, which is connected to the resistor Re5, which is connected to the negative electrode of the battery; the third path is connected to the inductor Le1, which is connected to the current limiting and voltage stabilizing circuit; the fourth path is connected to the resistor Re4, which is connected to the capacitor Ce1. 2. The fifth path is connected to the diode De2, and the diode De2 is connected to the capacitor Ce2; it also includes capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2, and one end of the capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2 after being connected in parallel is connected to the diode De2, and the other end is connected to three paths, the first path is connected to the resistor ReL1, the resistor ReL1 is connected to the negative pole of the battery, the first path is connected to the resistor ReL2, the resistor ReL2 is connected to the negative pole of the battery, the third path is connected to the resistor Re2, the resistor Re2 is connected to the capacitor Ce4, and the capacitor Ce4 is grounded; the two ends of the diode TVSe2 are respectively welded to the positive and negative pads of the auxiliary light source.

[0008] The current limiting and voltage stabilizing circuit includes two resistors ReD1 and ReD2 connected in parallel. One end of the resistor ReD1 and the resistor ReD2 is connected to the inductor Le1 , and the other end outputs a boost voltage out VDD.

[0009] In summary, the present invention has achieved the following technical effects:

[0010] The utility model is set to control the power switch N531 to obtain the PWM signal from the single chip microcomputer to control the switch of the MOS tube, cooperate with the inductor to achieve the boost function, and cooperate with the transistor VPe1 to prevent the instantaneous large current from damaging the device;

[0011] The utility model receives a PWM signal from Re3 and starts to control N531 to turn on and drive the BOOST circuit. When the switch is turned off (MOS tube QNe1 is cut off), due to the current retention characteristic of the inductor, the current flowing through the inductor does not immediately become 0, but slowly becomes 0. That is, the inductor begins to charge ce101, and the voltage across ce101 increases. At this point, the voltage is higher than the input voltage, and the boost is complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a circuit diagram provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0013] The present invention will be described in further detail below with reference to the accompanying drawings.

[0014] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

[0015] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0017] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0018] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0019] Example:

[0020] like Figure 1 As shown, a boost control circuit for an auxiliary light source of an LED street lamp includes a control power switch N531, a boost circuit, and a current limiting and voltage stabilizing circuit. Pin 5 of the control power switch N531 is connected to a resistor Re3, which is connected to a PWM output port of a single-chip microcomputer. Pin 5 of the control power switch N531 is also connected to a transistor VNe1, and the base of the transistor VNe1 receives an Imax out signal.

[0021] Pin 3 of the control power switch N531 is the output end connected to the input end of the boost circuit. One path of the boost circuit is connected to the auxiliary light source pad, and the other path is connected to the current limiting and voltage stabilizing circuit. The current limiting and voltage stabilizing circuit outputs the boost voltage out VDD.

[0022] The utility model uses resistor Re3 to receive the PWM signal from the microcontroller, thereby turning on the control power switch N531. It also receives the Imax out signal from the microcontroller to prevent the instantaneous high current from damaging the control power switch N531. The boost circuit outputs the 8W load pad to drive the auxiliary light source to boost the voltage.

[0023] Pin 5 of the control power switch N531 is also connected to the collector of the transistor VNe1, the emitter of the transistor VNe1 is connected to the negative electrode of the battery, pin 1 of the control power switch N531 is connected to capacitor Ce5, capacitor Ce5 is connected to the negative electrode of the battery, and pin 1 is connected to Vdd 12V; pin 3 of the control power switch N531 is connected to diode De1 on one side and to the base of the transistor VPe1 on the other side, diode De1 is connected to resistor Re1, resistor Re1 is connected to the emitter of the transistor VPe1, and the collector of the transistor VPe1 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to resistor Re7, and resistor Re7 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to the input end of the boost circuit.

[0024] Resistor Re3 is a current limiting resistor, transistor VNe1 is used for instantaneous high current hardware protection, capacitor Ce5 is used for filtering, and resistor Re7 is a pull-down resistor.

[0025] The boost circuit includes a MOS transistor QNe1, the gate of which is connected to the emitter of the transistor VPe1 in one path and to the diode Dez1 in the other path, which is connected to the negative electrode of the battery; the source of the MOS transistor QNe1 is connected to the negative electrode of the battery; the drain of the MOS transistor QNe1 is divided into five paths, the first path is connected to the diode TVSe1, which is connected to the negative electrode of the battery; the second path is connected to the capacitor Ce1, which is connected to the resistor Re5, which is connected to the negative electrode of the battery; the third path is connected to the inductor Le1, which is connected to the current limiting and voltage stabilizing circuit; and the fourth path is connected to the resistor Re4, which is connected to the capacitor Ce2. , the fifth path is connected to the diode De2, and the diode De2 is connected to the capacitor Ce2; it also includes capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2, and one end of the capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2 after being connected in parallel is connected to the diode De2, and the other end is connected to three paths, the first path is connected to the resistor ReL1, the resistor ReL1 is connected to the negative pole of the battery, the first path is connected to the resistor ReL2, the resistor ReL2 is connected to the negative pole of the battery, and the third path is connected to the resistor Re2, the resistor Re2; connected to capacitor Ce4, capacitor Ce4 is grounded; the two ends of the diode TVSe2 are respectively welded to the positive and negative pads of the auxiliary light source.

[0026] MOS tube QNe1 is the switch of the boost circuit, Ce101 is used for energy storage filtering to make the boost circuit work more smoothly, resistors ReL1 and ReL2 are sampling resistors used to detect voltage and determine output current, resistor Re2 is a current limiting resistor, and capacitors Ce1, Ce2, Ce3, and Ce4 are used for filtering.

[0027] Diode DE2 prevents the capacitor from discharging to the ground, TVSe1 and TVSe2 prevent surge voltage, VPE1 prevents instantaneous large current, and RE7 is the circuit pull-down resistor.

[0028] The current limiting and voltage stabilizing circuit includes two resistors ReD1 and ReD2 connected in parallel. One end of the resistor ReD1 and the resistor ReD2 is connected to the inductor Le1 , and the other end outputs a boost voltage out VDD.

[0029] Transistor VNe1 adopts S9014 / SOT-23, transistor VPe1 adopts SS8550 / Y2 / SOT-23, MOS tube QNe1 adopts GL1S50N06A4 / TO-252, and control power switch N531 adopts SOT23-5.

[0030] Working principle:

[0031] Resistor Re3 receives a PWM signal and controls N531 to turn on and drive the boost circuit. When MOS transistor QNe1 is turned off, that is, the switch is disconnected, the current flowing through inductor Le1 does not immediately drop to zero due to the current retention characteristic of inductor Le1, but slowly drops to zero. This means that the inductor begins to charge capacitor ce101, and the voltage across capacitor ce101 increases. At this point, the voltage is higher than the input voltage, and the boost is complete. The output is output from the 8W load pad to the auxiliary light source.

[0032] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A boost control circuit for an auxiliary light source of an LED street lamp, characterized by: It includes a control power switch N531, a boost circuit, and a current limiting and voltage stabilizing circuit. Pin 5 of the control power switch N531 is connected to a resistor Re3, which is connected to the PWM output port of the microcontroller. Pin 5 of the control power switch N531 is also connected to a transistor VNe1, and the base of the transistor VNe1 receives the Imax out signal. Pin 3 of the control power switch N531 is an output end connected to the input end of the boost circuit. One path of the boost circuit is connected to the auxiliary light source pad, and the other path is connected to the current limiting and voltage stabilizing circuit.

2. The LED street lamp auxiliary light source boost control circuit according to claim 1, characterized in that: Pin 5 of the control power switch N531 is also connected to the collector of the transistor VNe1, the emitter of the transistor VNe1 is connected to the negative electrode of the battery, pin 1 of the control power switch N531 is connected to capacitor Ce5, capacitor Ce5 is connected to the negative electrode of the battery, and pin 1 is connected to Vdd 12V; pin 3 of the control power switch N531 is connected to diode De1 on one side and to the base of the transistor VPe1 on the other side, diode De1 is connected to resistor Re1, resistor Re1 is connected to the emitter of the transistor VPe1, and the collector of the transistor VPe1 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to resistor Re7, and resistor Re7 is connected to the negative electrode of the battery; the emitter of the transistor VPe1 is connected to the input end of the boost circuit.

3. The LED street lamp auxiliary light source boost control circuit according to claim 2, characterized in that: The boost circuit includes a MOS transistor QNe1, the gate of which is connected to the emitter of the triode VPe1 in one path and to the diode Dez1 in the other path, which is connected to the negative electrode of the battery; the source of the MOS transistor QNe1 is connected to the negative electrode of the battery; the drain of the MOS transistor QNe1 is divided into five paths, the first path is connected to the diode TVSe1, which is connected to the negative electrode of the battery; the second path is connected to the capacitor Ce1, which is connected to the resistor Re5, which is connected to the negative electrode of the battery; the third path is connected to the inductor Le1, which is connected to the current limiting and voltage stabilizing circuit; the fourth path is connected to the resistor Re4, which is connected to the capacitor Ce1.

2. The fifth path is connected to the diode De2, and the diode De2 is connected to the capacitor Ce2; it also includes capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2, and one end of the capacitor Ce101, resistor Re6, capacitor Ce3, and diode TVSe2 after being connected in parallel is connected to the diode De2, and the other end is connected to three paths, the first path is connected to the resistor ReL1, the resistor ReL1 is connected to the negative pole of the battery, the first path is connected to the resistor ReL2, the resistor ReL2 is connected to the negative pole of the battery, the third path is connected to the resistor Re2, the resistor Re2 is connected to the capacitor Ce4, and the capacitor Ce4 is grounded; the two ends of the diode TVSe2 are respectively welded to the positive and negative pads of the auxiliary light source.

4. The LED street lamp auxiliary light source boost control circuit according to claim 2, characterized in that: The current limiting and voltage stabilizing circuit includes two resistors ReD1 and ReD2 connected in parallel. One end of the resistor ReD1 and the resistor ReD2 is connected to the inductor Le1 , and the other end outputs a boost voltage out VDD.

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