CN105828489A - LED light modulation device based on H-bridge circuit - Google Patents

Abstract

The invention discloses an LED dimming device based on an H-bridge circuit, comprising a dimming signal module, an LED light source module, a power supply module and an H-bridge circuit, wherein the LED light source module is used as a common bridge arm in the H-bridge circuit The load on the LED light source module is powered by high-frequency positive and negative pulses, and the effect of two-line control of dimming and color adjustment is achieved by controlling the pulse width of the high-frequency module, so that existing products can be easily transformed. Effectively reduce the difficulty of transformation and save the cost of transformation.

Description

A LED dimming device based on H-bridge circuit

technical field

The invention relates to the technical field of LED driving, in particular to an LED dimming device based on an H bridge circuit.

Background technique

Connect two of the four switching tubes, and connect the other two switching tubes and connect them through a common line. Because of this connection and the load on the public line, it often looks like an H when drawn, so it is The name H bridge, the four switch tubes are usually called bridge arms, and the common line in the middle is usually called a common bridge arm. The H-bridge circuit can be in the same circuit, so that the bridge arms on both sides always maintain the opposite output, so that the polarity of the load can be reversed in the case of a single power supply to meet the needs of motor drive and other aspects.

As a high-efficiency new light source, LED lights are widely used in various occasions such as shopping malls, urban roads, advertising light boxes, and automotive lighting due to their long life, low energy consumption, energy saving and environmental protection. People's requirements for LED lights are getting higher and higher, forming a variety of requirements from single brightness adjustment to color temperature adjustment and a combination of multiple adjustment methods. In order not to affect the color temperature drift of the LED, most of the LED lights that adjust the brightness and color temperature adopt the PWM (PulseWidthModulation, pulse width modulation) method.

At present, there are already many LED products with dimming, brightness, and color temperature adjustments on the market. Most of them use cool white LEDs and warm white LEDs for separate control or common cathode and common anode. One or more connecting wires, in the current structure similar to the wiring light and the pole light, there are only two electrical connecting wires, and there is no way to adjust the color temperature. It is necessary to add an electrical connecting wire. In this case, the original product mold must be Redo and increase the user's installation difficulty.

Contents of the invention

The technical problem to be solved by the present invention is to provide an LED dimming device based on an H-bridge circuit in view of the above-mentioned deficiencies in the prior art.

In order to solve the above technical problems, the technical solution adopted by the present invention is: an LED dimming device based on an H-bridge circuit, including a dimming signal module, an LED light source module, a power supply module, a first switch unit Q1, a second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4, the first switch unit Q1, the second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4 form an H-bridge circuit, wherein the LED The light source module acts as the load on the common bridge arm in the H-bridge circuit;

The dimming signal module includes a low color temperature carrier frequency circuit, a high color temperature carrier frequency circuit and a wireless module. The wireless module is electrically connected to the low color temperature carrier frequency circuit and the high color temperature carrier frequency circuit respectively. The low color temperature carrier frequency circuit , the high color temperature carrier frequency circuit is electrically connected to the H-bridge circuit;

The LED light source module is composed of low color temperature LED lamps and high color temperature LED lamps connected in parallel, and adjacent parallel LED lamps are connected in reverse.

In the above technical solution, both the low color temperature carrier frequency circuit and the high color temperature carrier frequency circuit respectively use a digital-to-analog converter to receive the digital signal sent by the wireless module, and output PWM at a corresponding frequency to control the LED light source module. The control can realize the adjustment of color temperature and brightness respectively.

In the above technical solution, the wireless module is a bluetooth module, which receives a bluetooth signal and converts it into a digital signal and transmits it to the digital-to-analog converter.

In the above technical solution, the first switch unit Q1, the second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4 are transistor MOSFETs.

In the above technical solution, a Zener diode is connected in parallel between the drain and the source of the transistor MOSFET.

In the above technical solution, the low color temperature carrier frequency circuit is connected to the gates of the second switch unit Q2 and the fourth switch unit Q4 respectively, and the high color temperature carrier frequency circuit is connected to the first switch unit Q1 and the third switch unit Q3 respectively. grid connection; one end of the LED light source module is connected between the first switch unit Q1 and the third switch unit Q3, and the other end of the LED light source module is connected between the second switch unit Q2 and the fourth switch unit Between Q4; the positive pole of the power supply module is connected to the drains of the first switch unit Q1 and the second switch unit Q2, and the negative pole is connected to the sources of the third switch unit Q3 and the fourth switch unit Q4.

In the above technical solution, the node between the second switch unit Q2 and the fourth switch unit Q4 is electrically connected to the low color temperature carrier frequency circuit through a capacitor C5, and the capacitor C5 is electrically connected to the diode D2 and through which the self-disconnection is performed. boost voltage; the node between the first switch unit Q1 and the third switch unit Q3 is electrically connected to the high color temperature carrier frequency circuit through a capacitor C2, and the capacitor C2 is electrically connected to the diode D1 and is bootstrapped through it For voltage boosting, the anodes of the diode D1 and the diode D2 are electrically connected to the power supply module.

In the above technical solution, the power supply module is electrically connected to the wireless module through a voltage stabilizer.

In the above technical solution, the power supply module is electrically connected with a polar capacitor C1 and a Schottky diode D3.

The beneficial effects of the present invention are: supply power to the LED light source module by means of high-frequency positive and negative pulses, and achieve the effect of two-line control of dimming and color adjustment by controlling the pulse width of the high-frequency module, so that the existing products can be easily Realize transformation, effectively reduce the difficulty of transformation and save transformation cost.

Description of drawings

Fig. 1 is a schematic diagram of circuit principle of the present invention;

Fig. 2 is a schematic diagram of PWM with two frequencies in the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 1, an LED dimming device based on an H-bridge circuit includes a dimming signal module, an LED light source module, a power supply module, a first switch unit Q1, a second switch unit Q2, a third switch unit Q3 and The fourth switch unit Q4, the first switch unit Q1, the second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4 form an H bridge circuit, wherein the LED light source module is used as a common load on the bridge arm;

Wherein, the dimming signal module includes a low color temperature carrier frequency circuit U2, a high color temperature carrier frequency circuit U1, and a wireless module, and the wireless module is electrically connected to the low color temperature carrier frequency circuit U2 and the high color temperature carrier frequency circuit U1 respectively. The low color temperature carrier frequency circuit U2 and the high color temperature carrier frequency circuit Y1 are respectively electrically connected to the H-bridge circuit. Both the low color temperature carrier frequency circuit and the high color temperature carrier frequency circuit use a digital-to-analog converter DAC-8 to receive the digital signal sent by the wireless module, and output PWM with a corresponding frequency to control the LED light source module , to adjust the color temperature and brightness respectively. The two PWM frequencies shown in Figure 2 are used to control brightness and color temperature from top to bottom.

The LED light source module is composed of low color temperature LED lamps and high color temperature LED lamps connected in parallel, and adjacent parallel LED lamps are connected in reverse. There can be multiple low color temperature LED lamps and high color temperature LED lamps, and single color temperature LED lamps can be connected in series as a row.

Wherein, the wireless module is a bluetooth module BM-S02, which receives a bluetooth signal and converts it into a digital signal and transmits it to the digital-to-analog converter DAC-8. The Bluetooth module BM-S02 receives the adjustment instructions sent by the wireless device. Pins 15 and 16 of the Bluetooth module BM-S02 are electrically connected to pin 2 of the high color temperature carrier frequency circuit and pin 2 of the low color temperature carrier frequency circuit respectively.

Wherein, the first switch unit Q1 , the second switch unit Q2 , the third switch unit Q3 and the fourth switch unit Q4 are MOSFETs or BJTs. In this embodiment, NMOS transistors are used.

Wherein, a Zener diode is connected in parallel between the drain and the source of the transistor MOSFET. The drains and sources of the first switch unit Q1 , the second switch unit Q2 , the third switch unit Q3 and the fourth switch unit Q4 are respectively connected in parallel with resistors R4 , R3 , R9 and R8 .

Wherein, the low color temperature carrier frequency circuit is respectively connected to the gates of the second switch unit Q2 and the fourth switch unit Q4, and the gate of the second switch unit Q2 is electrically connected to pin 7 of the low color temperature carrier frequency circuit through a resistor R1. The gate of the fourth switch unit Q4 is electrically connected to the pin 5 of the low color temperature carrier frequency circuit through the resistor R5; the high color temperature carrier frequency circuit is connected to the gates of the first switch unit Q1 and the third switch unit Q3 respectively. and the gate of the first switch unit Q1 is electrically connected to the pin 7 of the high color temperature carrier frequency circuit through the resistor R2, and the gate of the third switch unit Q3 is connected to the pin 5 of the high color temperature carrier frequency circuit through the resistor R6 Electrical connection; one end of the LED light source module is connected between the first switch unit Q1 and the third switch unit Q3, and the other end of the LED light source module is connected between the second switch unit Q2 and the fourth switch unit Q4 Between; the positive pole of the power supply module is connected to the drains of the first switch unit Q1 and the second switch unit Q2, and the negative pole is connected to the sources of the third switch unit Q3 and the fourth switch unit Q4.

Wherein, the node between the second switch unit Q2 and the fourth switch unit Q4 is electrically connected to the low color temperature carrier frequency circuit through a capacitor C5, and the capacitor C5 is electrically connected to the cathode of the diode D2 and is bootstrapped through it boosting voltage: the node between the first switch unit Q1 and the third switch unit Q3 is electrically connected to the high color temperature carrier frequency circuit through a capacitor C2, and the capacitor C2 is electrically connected to the negative pole of the diode D1 through which self- To boost the voltage, the anodes of the diode D1 and the diode D2 are electrically connected to the power supply module.

Wherein, the power supply module is electrically connected with the wireless module through a voltage regulator HT7533. The input terminal of the voltage regulator HT7533 is connected with resistor R7 and polarized capacitor C6 for filtering; the output terminal is connected with capacitor C7 for filtering. The power supply module is electrically connected with a polar capacitor C1 and a Schottky diode D3 for filtering and voltage stabilization. Furthermore, the power supply module is electrically connected with a fuse F1.

The above embodiments are only intended to illustrate rather than limit the present invention, so all equivalent changes or modifications made according to the methods described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims (9)

1. An LED dimming device based on an H-bridge circuit, comprising a dimming signal module, an LED light source module, a power supply module, a first switch unit Q1, a second switch unit Q2, a third switch unit Q3 and a fourth switch unit Q4, the first switch unit Q1, the second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4 form an H-bridge circuit, which is characterized in that: the LED light source module is used as a common bridge arm in the H-bridge circuit load on The dimming signal module includes a low color temperature carrier frequency circuit, a high color temperature carrier frequency circuit and a wireless module. The wireless module is electrically connected to the low color temperature carrier frequency circuit and the high color temperature carrier frequency circuit respectively. The low color temperature carrier frequency circuit , the high color temperature carrier frequency circuit is electrically connected to the H-bridge circuit; The LED light source module is composed of low color temperature LED lamps and high color temperature LED lamps connected in parallel, and adjacent parallel LED lamps are connected in reverse. 2. A kind of LED dimming device based on H bridge circuit according to claim 1, it is characterized in that: described low color temperature carrier frequency circuit and high color temperature carrier frequency circuit all adopt digital-to-analog converter to transmit to wireless module respectively The digital signal is received, and the PWM of the corresponding frequency is outputted to control the LED light source module, so as to realize the adjustment of the color temperature and brightness respectively. 3. A LED dimming device based on an H-bridge circuit according to claim 2, characterized in that: the wireless module is a Bluetooth module, which receives a Bluetooth signal and converts it into a digital signal and transmits it to the digital-to-analog converter . 4. The LED dimming device based on H-bridge circuit according to claim 1, characterized in that: the first switch unit Q1, the second switch unit Q2, the third switch unit Q3 and the fourth switch unit Q4 For the transistor MOSFET. 5 . The LED dimming device based on an H-bridge circuit according to claim 4 , wherein a Zener diode is connected in parallel between the drain and the source of the transistor MOSFET. 6 . 6. The LED dimming device based on an H-bridge circuit according to claim 4, wherein the low color temperature carrier frequency circuit is respectively connected to the gates of the second switch unit Q2 and the fourth switch unit Q4, The high color temperature carrier frequency circuit is respectively connected to the gates of the first switch unit Q1 and the third switch unit Q3; one end of the LED light source module is connected between the first switch unit Q1 and the third switch unit Q3, so The other end of the LED light source module is connected between the second switch unit Q2 and the fourth switch unit Q4; the positive pole of the power supply module is connected to the drains of the first switch unit Q1 and the second switch unit Q2, and the negative pole is connected to at the sources of the third switch unit Q3 and the fourth switch unit Q4. 7. An LED dimming device based on an H-bridge circuit according to claim 5, characterized in that: the node between the second switch unit Q2 and the fourth switch unit Q4 is connected to the low color temperature carrier frequency circuit through a capacitor C5 is electrically connected, and the capacitor C5 is electrically connected to the diode D2 through which the bootstrap boost is performed; the node between the first switch unit Q1 and the third switch unit Q3 is connected to the high color temperature carrier frequency circuit through the capacitor C2 and the capacitor C2 is electrically connected to the diode D1 through which the bootstrap voltage is boosted, and the anodes of the diode D1 and the diode D2 are electrically connected to the power supply module. 8. An LED dimming device based on an H-bridge circuit according to claim 1, wherein the power supply module is electrically connected to the wireless module through a voltage stabilizer. 9 . The LED dimming device based on an H bridge circuit according to claim 1 , wherein the power supply module is electrically connected with a polar capacitor C1 and a Schottky diode D3 .