Digital analog temperature control dimming circuit

Abstract

The utility model relates to the technical field of temperature control dimming circuits, and discloses a digital analog temperature control dimming circuit, which comprises a power supply input module, an LED lamp group module, a temperature control dimming module and a driving control module, the power input module is electrically connected with the driving control module, the output end of the driving control module is connected with the positive electrode of the LED lamp set module, the positive electrode of the LED lamp set module is electrically connected with the temperature control dimming module, and the other end of the temperature control dimming module is connected with the input end of the driving control module. And the cathode of the LED lamp group module is electrically connected with the cathode of the LED lamp group module. According to the utility model, the MCU processing process in the prior art is eliminated, and the NTC and chip linkage mode is directly adopted, so that the design cost and the use cost of a peripheral circuit are greatly reduced, and the reliability of the circuit is improved while the cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of temperature control dimming circuit technology, and in particular to a digital analog temperature control dimming circuit. Background Technology

[0002] Current temperature-controlled dimming mainly uses a temperature sensor (NTC) to collect temperature signals and send them to an MCU for processing. The MCU then sends PWM dimming pulses to the LED current chip to control the brightness of the LED.

[0003] The high cost is due to the need for MCU processing. Utility Model Content

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing a digital analog temperature control dimming circuit.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A digital analog temperature control dimming circuit includes a power input module, an LED lamp module, a temperature control dimming module, and a drive control module;

[0007] The power input module is electrically connected to the drive control module. The output terminal of the drive control module is connected to the positive terminal of the LED lamp module. The positive terminal of the LED lamp module is electrically connected to the temperature control dimming module. The other end of the temperature control dimming module is connected to the input terminal of the drive control module and is also electrically connected to the negative terminal of the LED lamp module.

[0008] Preferably, the power input module includes a power input terminal, a circuit protection module, and an EMC module that are electrically connected in sequence, and the EMC module is connected to the V1 N terminal of the drive control module through capacitors C2 and C3.

[0009] Preferably, the temperature control dimming module includes an NMOS transistor Q1. The positive terminal LED+ of the LED lamp module is connected to a resistor R7 and to the drain of the NMOS transistor Q1 through a resistor R9. The negative terminal LED- is connected to ground GND. The gate of the NMOS transistor Q1 is connected to a voltage divider circuit formed by an NTC thermistor and another resistor R9 in series. When the ambient temperature changes, the resistance of the NTC thermistor also changes, thereby changing the output voltage of the voltage divider circuit. This voltage signal is sent to the gate of the NMOS transistor to adjust the brightness of the LED. The source of the NMOS transistor Q1 is grounded to GND through a resistor R8 and is connected to the negative terminal LED- through resistors R6 and R5.

[0010] Preferably, the output terminal of the drive control module is connected to the positive terminal of the LED lamp module through an inductor L1.

[0011] Preferably, the LED light module includes LED1 and LED2 connected in series.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] This invention eliminates the MCU processing step in the prior art and directly adopts the NTC and chip linkage method, which greatly reduces the design and usage costs of the peripheral circuits, and improves the reliability of the circuit while reducing costs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a digital analog temperature control dimming circuit proposed in this utility model. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0016] Reference Figure 1 A digital analog temperature control dimming circuit includes a power input module, an LED lamp group module, a temperature control dimming module, and a drive control module.

[0017] The power input module is electrically connected to the drive control module. The output terminal of the drive control module is connected to the positive terminal of the LED lamp module. The positive terminal of the LED lamp module is electrically connected to the temperature control dimming module. The other end of the temperature control dimming module is connected to the input terminal of the drive control module and is also electrically connected to the negative terminal of the LED lamp module.

[0018] In this embodiment, the power input module includes a power input terminal, a circuit protection module, and an EMC module that are electrically connected in sequence. The EMC module is connected to the V1 N terminal of the drive control module through capacitors C2 and C3. The circuit protection module includes diodes D1 and D2 connected in reverse parallel to prevent damage to the circuit caused by reverse power connection or transient overvoltage.

[0019] In this embodiment, the temperature control dimming module includes an NMOS transistor Q1. The positive terminal LED+ of the LED lamp module is connected to the drain of the NMOS transistor Q1 through a 3.9K resistor R7 and a 3.9K resistor R9. The negative terminal LED- is connected to ground GND. The gate of the NMOS transistor Q1 is connected to a voltage divider circuit formed by an NTC thermistor and a 1K resistor R9 in series. When the ambient temperature changes, the resistance of the NTC thermistor also changes, thereby changing the output voltage of the voltage divider circuit. This voltage signal is sent to the gate of the NMOS transistor to adjust the brightness of the LED. The source of the NMOS transistor Q1 is connected to ground GND through a resistor R8, and is connected to a 1K resistor R9 and the other end of a diode D5. It is also connected to the negative terminal LED- through a resistor R6 and a 1K resistor R5. The other end of the diode D5 is connected to a resistor R7.

[0020] In this embodiment, the drive control module includes eight ports: VIN, DIM, SS, SW, BST, IFB, NC, and GND. The SW port is connected to the positive terminal of the LED module via a 33uH inductor L1, and its power input is connected to the VIN terminal. The SS terminal is grounded to GND via capacitor C4, and the GND port is also grounded to GND. The BST port is connected to the input terminal of inductor L1 via a 0.1uF capacitor C5 and a 4.7R resistor R1. The IFB terminal is connected to the source of NMOS transistor Q1 via a 27K resistor R6. Resistor R5 is grounded to GND via a 0.1R resistor RS1 and a resistor RS2, and one end of resistor R5 is connected to the other end of inductor L1 via a 2.2uF capacitor C7.

[0021] In this embodiment, the LED light group module includes LED1 and LED2 connected in series.

[0022] Compared to existing technologies, this circuit skips the intermediate MCU processing stage and links the temperature acquisition signal with the reference voltage of the LED current-carrying chip. When the temperature rises, the NTC resistor value decreases, and the voltage at point A increases. When the voltage rises to 1.2V, Q1 turns on, the chip's IFB voltage begins to increase, and the VFB voltage decreases, causing the LED current to decrease and the brightness to decrease. Conversely, as the brightness decreases, the temperature drops, the voltage at point A begins to decrease, and when it falls below 1.2V, Q1 turns off, the IFB voltage decreases, the VFB voltage increases, the LED current increases, and the brightness increases. This significantly reduces the need for external circuitry, lowering costs while improving circuit reliability.

[0023] It should be noted that all of the above connections constitute electrical connections.

[0024] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A digitally-analog temperature controlled dimming circuit, characterized by: The power input module, the LED lamp group module, the temperature control and light adjustment module and the drive control module are included. The power input module is electrically connected with the drive control module, the output end of the drive control module is connected with the positive pole of the LED lamp group module, the positive pole of the LED lamp group module is electrically connected with the temperature control and light adjustment module, the other end of the temperature control and light adjustment module is connected with the input end of the drive control module and is electrically connected with the negative pole of the LED lamp group module.

2. A digital analog temperature controlled dimming circuit as claimed in claim 1, wherein: The power input module includes the power input end, the circuit protection module and the EMC module which are electrically connected in sequence, and the EMC module is connected with the VIN end of the drive control module through the capacitors C2 and C3.

3. A digital analog temperature controlled dimming circuit as claimed in claim 1, wherein: the digital to analog converter is a digital to analog converter with a single input; and the single input is a digital input. 5 The temperature control and light adjustment module includes the NMOS tube Q1, the positive pole LED+ of the LED lamp group module is connected with the resistor R7, is connected with the drain of the NMOS tube Q1 through the resistor R9, the negative pole LED- is connected with the ground GND, the gate of the NMOS tube Q1 is connected with the voltage division circuit which is formed by the NTC thermistor and another resistor R9 in series, when the ambient temperature changes, the resistance of the NTC thermistor also changes, thereby changing the output voltage of the voltage division circuit, the voltage signal is sent into the gate of the NMOS tube, for adjusting the brightness of the LED lamp, the source of the NMOS tube Q1 is grounded through the resistor R8 and is connected with the negative pole LED- through the resistors R6 and R5.

4. A digital analog temperature controlled dimming circuit as claimed in claim 3, wherein: The output end of the drive control module is connected with the positive pole of the LED lamp group module through the inductor L1.

5. The digital analog temperature control dimming circuit according to claim 1, characterized in that: The LED lamp group module includes the LED1 and the LED2 which are connected in series.

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