Circuit for setting starting time

Abstract

The invention discloses a circuit for setting starting time, and relates to the technical field of LED drivers, and the circuit comprises an LED power circuit, one side of the LED power circuit is electrically connected with a control switch through a first wire, and the other side of the LED power circuit is electrically connected to an input voltage rectification circuit through a second wire. The other side of the input voltage rectifying circuit is electrically connected with a control lamp through a third wire, the control lamp is electrically connected to the input voltage rectifying circuit through a fourth wire, and the bottom end of the input voltage rectifying circuit is electrically connected with the fourth wire. According to the invention, the structure is reasonable, the NFC control circuit can convert the required starting time into the corresponding pull-down current after the required starting time is written into the NFC reader-writer, so that a part of the starting current is shunted, and the starting time is set as the target starting time.

Description

Technical Field

[0001] The present invention relates to the technical field of LED drivers, and in particular to a circuit for setting a start-up time. Background Art

[0002] LED driver refers to the power regulating electronic device that drives LED to emit light or LED module components to work normally. Due to the conduction characteristics of LED PN junction, the voltage and current variation range of the power supply it can use is very narrow. A slight deviation may fail to light up the LED or seriously reduce the luminous efficiency, or shorten the service life or even burn the chip. The current ACDC power supply or LED driver starts working after a relatively fixed startup time (from power-on to load operation), and the startup time is unchangeable.

[0003] However, in the current circuit design, after the power is turned on, the chip is charged through the resistor R1 and the capacitor C1 in the dotted box. When the voltage reaches a certain threshold, the chip starts and the product starts working. This time is determined by the resistor R1 and the capacitor C1. The resistor R1 and the capacitor C1 cannot be changed after they are designed, so the startup time cannot be changed. Therefore, the present application provides a circuit for setting the startup time to meet the needs. Summary of the invention

[0004] The purpose of the present application is to provide a circuit for setting the startup time, which realizes that after writing the required startup time in the NFC reader, the NFC control circuit will convert it into a corresponding pull-down current, so that a part of the startup current is diverted, so that the startup time is set to the target startup time.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a circuit for setting a start-up time, comprising an LED power circuit, one side of the LED power circuit is electrically connected to a control switch through a first wire, and the other side of the LED power circuit is electrically connected to an input voltage rectification circuit through a second wire, the other side of the input voltage rectification circuit is electrically connected to a control lamp through a third wire, the control lamp is electrically connected to the input voltage rectification circuit through a fourth wire, and the bottom end of the input voltage rectification circuit is electrically connected to a fourth wire, a resistor R1 is provided on the fourth wire, and the other end of the fourth wire is electrically connected to a power control chip, and the power control chip is electrically connected to the LED power circuit through a fifth wire.

[0006] Preferably, the fourth wire is electrically connected to the sixth wire, and the sixth wire is converted into a corresponding pull-down current, the other end of the sixth wire is electrically connected to the NFC controller circuit, the NFC controller circuit is electrically connected to the NFC antenna through the seventh wire, and the NFC antenna is connected to the NFC reader through wireless transmission technology.

[0007] Preferably, the fourth wire is electrically connected to the eighth wire, a capacitor C1 is provided on the eighth wire, and the other end of the eighth wire is fixedly connected to the power control chip.

[0008] Preferably, the NFC antenna radiates electromagnetic waves into the air to transmit electromagnetic signals. In order to radiate electromagnetic signals into the air, the length of the antenna needs to be comparable to the working wavelength. The length of a simple half-wave dipole antenna is 1 / 2 wavelength, and that of a monopole antenna is 1 / 4 wavelength. Corresponding to an operating frequency of 13.56 MHz, the size of a half-wave dipole antenna is 11.06 m, and the size of a monopole antenna is 5.03 m. However, 13.56 MHz NFC transmits electromagnetic signals through near-field coupling, and the antenna working distance is much smaller than that of a traditional antenna. The working distance of ISO14443-A / B is only 10 cm, and the maximum working distance of SO15693 is 1 m.

[0009] Preferably, the resistor R1 is used to limit the current in the circuit to prevent the base voltage of transistor VT1 from being equal to the power supply voltage VCC when the resistance of the variable resistor is adjusted to the minimum. In that case, VT1 will be damaged due to excessive base current of VT1. Such a resistor is generally called a protection resistor in the circuit.

[0010] Preferably, the rectifier circuit is a circuit that converts AC power into DC power. The rectifier circuits in the power supply circuit mainly include three types: half-wave rectifier circuit, full-wave rectifier circuit and bridge rectifier circuit. The function of the rectifier circuit is to convert the lower voltage AC power output by the AC step-down circuit into unidirectional pulsating DC power.

[0011] Preferably, the working state when the input, load and control of the power control chip are all fixed values ​​is called steady state in the switching power supply. In steady state, the inductance in the power converter satisfies the inductor voltage volt-second balance law. For the DC / DC power converter that has been working in steady state, the forward volt-second applied to the filter inductor when the active switch is turned on must be equal to the reverse volt-second applied to the inductor when the active switch is turned off.

[0012] In summary, the technical effects and advantages of the present invention are as follows:

[0013] The present invention has a reasonable structure. The user places the card on the NFC reader / writer, and then the reader / writer processes the information received by the NFC reader / writer through wireless transmission technology, and then transmits the sorted instructions to the NFC antenna through wireless transmission technology. When the NFC antenna receives the instruction, it transmits the instruction to the NFC controller circuit through a wire. The NFC control circuit will convert it into a corresponding pull-down current, so that a part of the startup current is diverted, so that the startup time is set to the target startup time, thereby achieving the purpose of changing the startup time delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 It is a typical design schematic diagram of the present invention;

[0016] Figure 2 Schematic diagram of the equivalent resistance of the NFC antenna of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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.

[0018] Example: Reference Figure 1 A circuit for setting a start time is shown, comprising an LED power circuit, one side of the LED power circuit is electrically connected to a control switch via a first wire, and the other side of the LED power circuit is electrically connected to an input voltage rectifier circuit via a second wire, the other side of the input voltage rectifier circuit is electrically connected to a control lamp via a third wire, the control lamp is electrically connected to the input voltage rectifier circuit via a fourth wire, and the bottom end of the input voltage rectifier circuit is electrically connected to a fourth wire, a resistor R1 is provided on the fourth wire, and the other end of the fourth wire is electrically connected to a power control chip, and the power control chip is electrically connected to the LED power circuit via a fifth wire.

[0019] Specifically, it should be noted that the internal control units of the LED power circuit and the input voltage rectification circuit are referenced through the existing technology, and the working principles therebetween are referenced through the existing technology, and no further elaboration is given here. When the customer uses it, after writing the required startup time in the NFC reader, the NFC control circuit will convert it into a corresponding pull-down current, so that a part of the startup current is diverted, thereby setting the startup time to the target startup time.

[0020] As a preferred implementation manner in this embodiment, the fourth wire is electrically connected to the sixth wire, and the sixth wire is converted into a corresponding pull-down current, the other end of the sixth wire is electrically connected to the NFC controller circuit, the NFC controller circuit is electrically connected to the NFC antenna through the seventh wire, the NFC antenna is connected to the NFC reader through wireless transmission technology, the fourth wire is electrically connected to the eighth wire, a capacitor C1 is provided on the eighth wire, and the other end of the eighth wire is fixedly connected to the power control chip.

[0021] In this embodiment, the NFC antenna radiates electromagnetic waves into the air to transmit electromagnetic signals. In order to radiate electromagnetic signals into the air, the length of the antenna needs to be comparable to the working wavelength. The length of a simple half-wave dipole antenna is 1 / 2 wavelength, and the length of a monopole antenna is 1 / 4 wavelength. Corresponding to the working frequency of 13.56MHz, the size of the half-wave dipole antenna is 11.06m, and the size of the monopole antenna is 5.03m. However, the 13.56MHzNFC transmits electromagnetic signals through near-field coupling, and the antenna working distance is much smaller than that of traditional antennas. The working distance of ISO14443-A / B is only 10cm, and the farthest working distance of SO15693 is 1m. The 13.56MhzNFC antenna can be regarded as a coupled coil. According to Ampere's law, when current flows through a section of wire, a magnetic field will be generated around the conductor, and the magnetic field induction intensity is proportional to the number of coil turns and the coil area, and decays with the cube of the distance. According to Faraday's law of electromagnetic induction, a time-varying magnetic field passing through a closed space will generate an induced voltage. Therefore, these two laws are applied to NFC readers and NFC cards respectively. The reader antenna generates a magnetic field that couples to the NFC card antenna to generate voltage energy to activate the chip in the NFC card, thereby transmitting energy and signals. Resistor R1 is used to limit the current in the circuit to prevent the variable resistor from being adjusted to the minimum value, so that the base voltage of the transistor VT1 is equal to the power supply voltage VCC. In that case, VT1 will be damaged due to excessive base current of VT1. This kind of resistor is generally called a protection resistor in the circuit. The rectifier circuit is a circuit that converts AC power into DC power. The rectifier circuit in the power supply circuit mainly There are three types of half-wave rectifier circuits, full-wave rectifier circuits and bridge rectifier circuits. The function of the rectifier circuit is to convert the low-voltage AC output of the AC step-down circuit into unidirectional pulsating DC. The working state when the input, load and control of the power control chip are fixed values ​​is called steady state in the switching power supply. In steady state, the inductor in the power converter satisfies the inductor voltage volt-second balance law. For the DC / DC power converter that has been working in steady state, the forward volt-second applied to the filter inductor when the active switch is turned on must be equal to the reverse volt-second applied to the inductor when the active switch is turned off; the equivalent resistance of the NFC antenna is shown in the attached Figure 2 ,

[0022] Specifically, the power grid supplies users with alternating current, while various radio devices require direct current. Rectification is the process of converting alternating current into direct current. Using devices with unidirectional conductive properties, alternating current with changed direction and magnitude can be converted into direct current;

[0023] There are also four types of rectifier circuits;

[0024] The first is half-wave rectification. In general, a half-wave rectification circuit only needs one diode. VD is turned on during the positive half cycle of the AC power and is turned off during the negative half cycle. The load R receives pulsating DC power.

[0025] The second is full-wave rectification. Full-wave rectification requires two diodes. ASEMI engineering also requires two secondary coils with center taps. The two secondary coils need to have the same number of turns to ensure the same resistance. The load RL gets the full-wave rectified current, and the output voltage is higher than the half-wave rectifier circuit.

[0026] The third type is our common full-wave bridge rectifier. Our ASEMI rectifier bridge is generally full-wave bridge rectifier. The full-wave bridge rectifier uses a bridge circuit composed of 4 diodes. This circuit can only have a transformer with a single secondary coil. The current waveform and output voltage value on the load are exactly the same as the second full-wave rectifier circuit.

[0027] The last type is voltage doubler rectification. This rectifier circuit uses multiple diodes and capacitors to obtain a higher DC voltage.

[0028] The function of the rectifier circuit is to convert the low-voltage AC output of the AC step-down circuit into unidirectional pulsating DC. This is the rectification process of AC. The rectifier circuit is mainly composed of rectifier diodes. The voltage after the rectifier circuit is no longer an AC voltage, but a mixed voltage containing DC voltage and AC voltage. It is usually called a unidirectional pulsating DC voltage.

[0029] The working principle of this utility model is as follows: the user places the card on the NFC reader / writer, and then the reader / writer processes the information received by the NFC reader / writer through wireless transmission technology, and then transmits the sorted instructions to the NFC antenna through wireless transmission technology. When the NFC antenna receives the instruction, it transmits the instruction to the NFC controller circuit through a wire. The NFC control circuit will convert it into a corresponding pull-down current, so that a part of the startup current is diverted, so that the startup time is set to the target startup time, thereby achieving the purpose of changing the startup time delay.

[0030] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A circuit for setting a startup time, characterized in that: It includes an LED power circuit, one side of the LED power circuit is electrically connected to a control switch through a first wire, and the other side of the LED power circuit is electrically connected to an input voltage rectification circuit through a second wire, the other side of the input voltage rectification circuit is electrically connected to a control lamp through a third wire, the control lamp is electrically connected to the input voltage rectification circuit through a fourth wire, and the bottom of the input voltage rectification circuit is electrically connected to a fourth wire, a resistor R1 is provided on the fourth wire, and the other end of the fourth wire is electrically connected to a power control chip, and the power control chip is electrically connected to the LED power circuit through a fifth wire.

2. A circuit for setting a startup time according to claim 1, characterized in that: The fourth wire is electrically connected to the sixth wire, and the sixth wire is converted into a corresponding pull-down current. The other end of the sixth wire is electrically connected to the NFC controller circuit. The NFC controller circuit is electrically connected to the NFC antenna through the seventh wire. The NFC antenna is connected to the NFC reader through wireless transmission technology.

3. A circuit for setting a startup time according to claim 1, characterized in that: The fourth wire is electrically connected to the eighth wire, a capacitor C1 is provided on the eighth wire, and the other end of the eighth wire is fixedly connected to the power control chip.

4. A circuit for setting a startup time according to claim 2, characterized in that: The NFC antenna radiates electromagnetic waves into the air to transmit electromagnetic signals. In order to radiate electromagnetic signals into the air, the length of the antenna needs to be comparable to the working wavelength. The length of a simple half-wave dipole antenna is 1 / 2 wavelength, and that of a monopole antenna is 1 / 4 wavelength. Corresponding to an operating frequency of 13.56 MHz, the size of a half-wave dipole antenna is 11.06 m, and that of a monopole antenna is 5.03 m. However, 13.56 MHz NFC transmits electromagnetic signals through near-field coupling, and the antenna working distance is much smaller than that of a traditional antenna. The working distance of ISO14443-A / B is only 10 cm, and the maximum working distance of SO15693 is 1 m.

5. The circuit for setting the start-up time according to claim 1, characterized in that: The resistor R1 is used to limit the current in the circuit to prevent the variable resistor from being adjusted to the minimum value, so that the base voltage of the transistor VT1 is equal to the power supply voltage VCC. In that case, VT1 will be damaged due to excessive base current of VT1. This kind of resistor is generally called a protection resistor in the circuit.

6. The circuit for setting the start-up time according to claim 1, characterized in that: The rectifier circuit is a circuit that converts AC power into DC power. There are three main types of rectifier circuits in the power supply circuit: half-wave rectifier circuit, full-wave rectifier circuit and bridge rectifier circuit. The function of the rectifier circuit is to convert the low-voltage AC power output by the AC step-down circuit into unidirectional pulsating DC power.

7. The circuit for setting the start-up time according to claim 1, characterized in that: The working state of the power control chip when the input, load and control are all fixed values ​​is called steady state in the switching power supply. In steady state, the inductor in the power converter satisfies the inductor voltage volt-second balance law. For the DC / DC power converter that has been working in steady state, the forward volt-second applied to the filter inductor when the active switch is turned on must be equal to the reverse volt-second applied to the inductor when the active switch is turned off.

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