A white light detection circuit and system thereof

Abstract

This application relates to the technical field of lighting simulation circuits, and in particular to a white light detection circuit and system thereof. The white light detection circuit includes a power supply module, a switch module, a detection port, and a level port. The power supply module is used for power supply voltage. The first port of the switch module is connected to the detection port, the second port is connected to the power supply module, and the third port is grounded. The level port is connected between the second port of the switch module and the power supply module. The detection port is used to detect the first level signal on the white light W circuit when the light strip outputs white light and outputs a corresponding detection signal. The switch module switches on and off according to the detection signal, and the level port outputs a corresponding second level signal according to the switching on and off of the switch module. The white light detection system includes the above-mentioned white light detection circuit, and also includes a power supply module and red light R circuit, green light G circuit, blue light B circuit, and white light W circuit connected in parallel. This application can improve the detection effect of white light pixel W.

Description

Technical Field

[0001] This application relates to the technical field of lighting simulation circuits, and in particular to a white light detection circuit and system thereof. Background Technology

[0002] LED light strips are electronic products commonly used in daily life for lighting, beautification, and decoration. Existing LED light strips include two types: monochrome and multicolor. Monochrome LED light strips contain only one color of pixels, while multicolor LED light strips contain at least two colors of pixels. Different colored pixels can be lit individually or in combination according to the application to form different colored lights.

[0003] Currently, there are two types of commonly used multi-color LED light strips: one is the RGB three-color light strip, and the other is the RGBW four-color light strip. R, G, and B represent red, green, and blue pixels, respectively, while W represents white sub-pixels.

[0004] When different types of LED light strips output white light, they have different control methods. For example, the white light output control method of an RGB three-color light strip is to simultaneously light up the red, green and blue pixels to mix and produce white light; while the RGBW four-color light strip, because it has white pixels connected, only needs to control the W to output, while the R, G and B pixels do not output.

[0005] In related technologies, in order for a single power supply driver to simultaneously power different types of multi-color LED strips, it is necessary to first test the electronic circuit to determine whether white light pixels exist in the circuit. Detection methods include series resistance detection and Hall sensor detection, among which:

[0006] like Figure 1 As shown, series resistance detection involves connecting a resistor in series in the load circuit of W, and detecting the voltage across the resistor using an external metering chip or operational amplifier circuit. This detects whether current flows through the circuit, its magnitude, and how it changes. The metering chip or operational amplifier circuit then feeds back the corresponding level signal, which is then judged by a microcontroller or similar device.

[0007] like Figure 2 As shown, the Hall sensor detection is based on the Hall effect principle (the Hall current sensor is based on the magnetic balance Hall principle. The current IC flows from the control current terminal of the Hall element, and a magnetic field with magnetic induction intensity B is applied in the normal direction of the Hall element plane. Then, an electric potential will be generated in the direction perpendicular to the current and the magnetic field, which is called the Hall potential, and its magnitude is proportional to the control current I). The Hall current sensor is connected in series in the load circuit of W. The electric potential generated by the current is processed by the chip to output the required signal.

[0008] In these two detection methods, the series resistor needs to be selected differently depending on the current, and it will cause certain losses to the circuit. The larger the voltage drop across the resistor, the greater the loss. If the voltage drop across the resistor is small, the chip detection becomes more difficult. On the other hand, the Hall sensor detection method, although it does not require taking voltage from the load circuit and therefore does not generate much loss, is more expensive. Summary of the Invention

[0009] To improve the detection effect of white light pixels W, this application provides a white light detection circuit and system.

[0010] Firstly, this application provides a white light detection circuit, which adopts the following technical solution:

[0011] A white light detection circuit includes a power supply module, a switch module, a detection port, and a level port. The power supply module is used for power supply voltage. The first port of the switch module is connected to the detection port, the second port is connected to the power supply module, and the third port is grounded. The level port is connected between the second port on the switch module and the power supply module.

[0012] The detection port is used to detect the first level signal on the white light W circuit when the LED strip outputs white light and outputs a corresponding detection signal. The switching module switches on and off according to the detection signal, and the level port outputs a corresponding second level signal according to the switching on and off of the switching module.

[0013] Preferably, the switching module includes a first MOSFET Q1, wherein the first port of the first MOSFET Q1 is the gate, the second port is the drain, and the third port is the source.

[0014] Preferably, the first MOS transistor Q1 is an N-MOS transistor.

[0015] Preferably, it also includes a first resistor R1, one end of which is connected to the drain of the first MOSFET Q1, and the other end is connected to the power module.

[0016] Preferably, it further includes a second resistor R2, one end of which is connected to the node between the drain of the first MOSFET Q1 and the power supply module, and the other end is connected to the level port.

[0017] Preferably, it further includes a third resistor R3, one end of which is connected between the gate of the first MOS transistor Q1 and the detection port, and the other end is connected to ground and the gate of the first MOS transistor Q1 respectively.

[0018] Secondly, the white light detection system provided in this application adopts the following technical solution:

[0019] A white light detection system includes the aforementioned white light detection circuit, and further includes a power supply module and a red light R circuit, a green light G circuit, a blue light B circuit, and a white light W circuit connected in parallel. The power supply module is connected to the red light R circuit, the green light G circuit, the blue light B circuit, and the white light W circuit respectively to provide power. The detection port in the white light detection circuit is connected to the white light W circuit and detects the first level signal on the white light W circuit when the light strip outputs white light to output a corresponding detection signal.

[0020] Preferably, it also includes an MCU module, which is connected to the level port to receive a second level signal and determines whether to connect the white light W based on the second level signal.

[0021] Preferably, it also includes a connection module, which is connected to the red light R circuit, green light G circuit, blue light B circuit, white light W circuit and white light detection circuit respectively. The connection module is used to connect the red light R circuit, green light G circuit, blue light B circuit, white light W circuit and white light detection circuit to subsequent equipment.

[0022] In summary, this application includes the following beneficial technical effects:

[0023] When the power module is already powered, if a white LED (W) is connected, a high level is detected on Vout. At this time, the gate of the first MOSFET Q1 is energized, causing the first MOSFET Q1 to conduct. Vd is connected to the source of the first MOSFET Q1 and becomes low. If no LED is connected, no voltage can be detected on Vout, so it is low. At this time, the first MOSFET Q1 is turned off, and Vd becomes a high-level signal. Vd is connected to the MCU chip, and the MCU chip determines whether a white LED (W) is connected at this time by the high or low level of Vd. Attached Figure Description

[0024] Figure 1 This is a circuit connection diagram when using series resistors for detection in related technologies;

[0025] Figure 2 This is a circuit connection diagram for using Hall sensors in related technologies;

[0026] Figure 3 This is a schematic diagram of the circuit connection of the white light detection circuit in the embodiments of this application;

[0027] Figure 4 This is a circuit connection diagram of the white light detection system in the embodiments of this application.

[0028] Explanation of reference numerals in the attached diagram: 1. Power supply module; 2. Switch module; 3. Detection port; 4. Level port; 5. Red light R circuit; 6. Green light G circuit; 7. Blue light B circuit; 8. White light W circuit; 9. Power supply module; 10. MCU module; 11. Connection module. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0030] This application discloses a white light detection circuit.

[0031] like Figure 3 As shown, a white light detection circuit includes a power supply module, a switch module, a detection port, and a level port.

[0032] The power module is used for power supply voltage, which is VCC in this embodiment.

[0033] The first port of the switch module is connected to the detection port, the second port is connected to the power supply module, the third port is grounded, and the level port is connected between the second port of the switch module and the power supply module.

[0034] The detection port is used to detect the first level signal on the white light W circuit when the light strip outputs white light to output a corresponding detection signal. The switching module switches on and off according to the detection signal, and the level signal outputs a corresponding second level signal according to the switching on and off of the switching module.

[0035] Furthermore, the switching module includes a first MOSFET Q1, with a first port serving as the gate of Q1, a second port serving as the drain of Q1, and a third port serving as the source of Q1. The first MOSFET Q1 is an N-MOSFET. The detection port is Vout, and the level port is Vd.

[0036] Based on the leakage current characteristics of LEDs, the above circuit forms a loop when an LED is connected, and there will be a corresponding voltage on VOUT. When no LED is connected, a loop cannot be formed, and there will be no voltage on Vout.

[0037] When VCC is already powered, if an LED is connected, a high level is detected on Vout. At this time, the gate of the first MOSFET Q1 is energized, causing the first MOSFET Q1 to conduct. Vd is connected to the source of the first MOSFET Q1 and becomes low. If no LED is connected, no voltage can be detected on Vout, so it is low. At this time, the first MOSFET Q1 is turned off, and Vd becomes a high level signal. Vd is connected to the MCU chip, and the MCU chip determines whether an LED is connected by the high or low level of Vd.

[0038] With the above circuit, there is no need to draw voltage from the load circuit, and the MOSFET only requires about 2V to turn on, so there is basically no loss. Moreover, compared with Hall sensor, MOSFET is also cheaper. This application can detect whether the white light W circuit is connected with relatively high accuracy at a lower cost, and the detection effect of white light W is better.

[0039] Furthermore, it also includes a first resistor R1, a second resistor R2, and a third resistor R3.

[0040] The first resistor R1 is connected at one end to the drain of the first MOSFET Q1, and at the other end to the power module. The first resistor R1 prevents the first MOSFET Q1 from being damaged by VCC, thus providing protection.

[0041] The second resistor R2 is connected at one end to the node between the drain of the first MOSFET Q1 and the power supply module, and at the other end to the level port.

[0042] The third resistor R3 is connected at one end between the gate and the detection port of the first MOSFET Q1, and at the other end to ground and the gate of the first MOSFET Q1. The third resistor R3 serves two purposes: providing bias current to the first MOSFET Q1 and acting as a discharge resistor. The resistance between the gate and source of a field-effect transistor (FET) is very high, so even a small amount of static electricity can generate a high voltage across the equivalent capacitance between its gate and source. If this small amount of static electricity is not discharged in time, the high voltage across the terminals may cause the FET to malfunction or even break down its gate and source terminals. The resistor added between the gate and source can discharge this static electricity, thus protecting the FET.

[0043] like Figure 4 As shown, this application also discloses a white light detection system, including the white light detection circuit described above, as well as a power supply module and red light R circuit, green light G circuit, blue light B circuit and white light W circuit connected in parallel.

[0044] The power supply module is connected to the red light (R) circuit, green light (G) circuit, blue light (B) circuit, and white light (W) circuit respectively to provide power. In this embodiment, the power supply module has a 12V input terminal.

[0045] The detection port in the white light detection circuit is connected to the white light W circuit and detects the first level signal on the white light W circuit when the light strip outputs white light to output the corresponding detection signal.

[0046] Specifically, the red light R circuit includes a red light-emitting diode LEDR, a first diode D1, and a second MOSFET Q2. The cathode of the first diode D1 is connected to the power supply module, and the anode is connected to the drain of the second MOSFET Q2. The anode of the red light-emitting diode LEDO is connected to the power supply module, and the cathode is connected to the drain of the second MOSFET Q2. The source of the second MOSFET Q2 is grounded, and the gate of the second MOSFET Q2 is connected to the red light control terminal U2.18. The first diode D1 and the red light-emitting diode LEDO are connected in parallel.

[0047] The green light R circuit includes a green light-emitting diode (LEDG), a second diode (D2), and a third MOSFET (Q3). The cathode of the second diode (D2) is connected to the power supply module, and the anode is connected to the drain of the third MOSFET (Q3). The anode of the green light-emitting diode (LEDG) is connected to the power supply module, and the cathode is connected to the drain of the third MOSFET (Q3). The source of the third MOSFET (Q3) is grounded, and the gate of the third MOSFET (Q3) is connected to the green light control terminal U2.17. The second diode (D2) and the green light-emitting diode (LEDG) are connected in parallel.

[0048] The blue light B circuit includes a blue light-emitting diode (LEDB), a third diode (D3), and a fourth MOSFET (Q4). The cathode of the third diode (D3) is connected to the power supply module, and the anode is connected to the drain of the fourth MOSFET (Q4). The anode of the blue light-emitting diode (LEDB) is connected to the power supply module, and the cathode is connected to the drain of the fourth MOSFET (Q4). The source of the fourth MOSFET (Q4) is grounded, and the gate of the fourth MOSFET (Q4) is connected to the blue light control terminal U2.16. The third diode (D3) and the blue light-emitting diode (LEDB) are connected in parallel.

[0049] The white light R circuit includes a white light-emitting diode (LEDW), a fourth diode (D4), and a fifth MOSFET (Q5). The cathode of the fourth diode (D4) is connected to the power supply module, and the anode is connected to the drain of the fourth MOSFET (Q4). The anode of the white light-emitting diode (LEDW) is connected to the power supply module, and the cathode is connected to the drain of the fifth MOSFET (Q5). The source of the fifth MOSFET (Q5) is grounded, and the gate of the fifth MOSFET (Q5) is connected to the white light control terminal U2.15. The fourth transistor (D4) and the white light-emitting diode (LEDW) are connected in parallel.

[0050] The detection port in the white light detection circuit is connected to the white light W circuit. Specifically, the detection port is connected to the node between the positive terminal of the fourth diode D4 and the negative terminal of the white light emitting diode LEDW.

[0051] It also includes an MCU module, which is connected to the level port to receive a second level signal and determines whether to connect the white light W based on the second level signal.

[0052] +12V is connected to the positive terminal of the LED, and the negative terminals of RGBW are connected to GND through four MOSFETs respectively. After the power driver is powered on, if the white light control terminal U2.15 does not provide a level, and no white light is connected, WLO will be at a low level, the first MOSFET Q1 will be turned off, and Vd will provide a high level. When the MCU module detects that Vd is at a high level, it indicates that no white light is connected. At this time, the white light output in the application is the white light mixed from the full illumination of the three RGB pixels. If white light is connected, and the white light control terminal U2.15 does not provide a level, WLO will be at a high level, the first MOSFET Q1 will be turned on, and Vd will provide a low level. When the MCU module detects that the level on Vd is low, it determines that the white light output in the application is the white light when the white pixel of W is lit, and at this time, the three RGB pixels are not lit.

[0053] Furthermore, it also includes a connection module, which is connected to the red light (R) circuit, green light (G) circuit, blue light (B) circuit, white light (W) circuit, and white light detection circuit, respectively. The connection module is used to connect the red light (R) circuit, green light (G) circuit, blue light (B) circuit, white light (W) circuit, and white light detection circuit to subsequent devices. In this embodiment, the connection module is a 5-pin connector, which can connect the light strip composed of the above system to devices such as computers, electronic communications, instruments, meters, card readers, and displays.

[0054] The five ports of the connection module are respectively connected to the power supply module, the negative terminal of the red light-emitting diode LEDR, the negative terminal of the green light-emitting diode LEDG, the negative terminal of the blue light-emitting diode LEDB, and the negative terminal of the white light-emitting diode LEDW.

[0055] The implementation principle is as follows:

[0056] When VCC is already powered, if the white LED W is connected, a high level is detected on Vout. At this time, the gate of the first MOSFET Q1 is energized, causing the first MOSFET Q1 to conduct. Vd is connected to the source of the first MOSFET Q1 and becomes low. If no LED is connected, no voltage can be detected on Vout, so it is low. At this time, the first MOSFET Q1 is turned off, and Vd becomes a high level signal. Vd is connected to the MCU chip, and the MCU chip determines whether the white LED W is connected at this time by the high or low level of Vd.

[0057] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A white light detection circuit, characterized in that: It includes a power module, a switch module, a detection port, and a level port. The power module is used for power supply voltage. The first port of the switch module is connected to the detection port, the second port is connected to the power module, and the third port is grounded. The level port is connected between the second port on the switch module and the power module. The detection port is connected to the white light W circuit of the light strip and is used to detect the first level signal generated by the leakage current of the white LED in the white light W circuit when the light strip outputs white light, so as to output a corresponding detection signal. The switching module performs corresponding switching on and off according to the detection signal, and the level port outputs a corresponding second level signal according to the switching on and off of the switching module. The switching module includes a first MOSFET Q1, wherein the first port of the first MOSFET Q1 is the gate, the second port is the drain, and the third port is the source; The first MOSFET Q1 is an N-MOS; The gate of the first MOSFET Q1 receives the detection signal, the drain of the first MOSFET Q1 is connected to the power supply module, and the level port is connected between the drain of the first MOSFET Q1 and the power supply module. When the detection port detects that the first level signal is high, the first MOS transistor Q1 is turned on, and the level port outputs a low level second level signal. When the detection port does not detect the first level signal, the first MOS transistor Q1 is turned off, and the level port outputs a high-level second level signal; It also includes a third resistor R3, one end of which is connected between the gate of the first MOS transistor Q1 and the detection port, and the other end is connected to ground and the gate of the first MOS transistor Q1 respectively. The detection port is connected to the node between the positive terminal of the fourth diode D4 and the negative terminal of the white light emitting diode LEDW; After the power supply is powered on, if the white light control terminal does not output a level, and an LED of white light W is connected, a high level is detected on the detection port, the gate of the first MOS transistor Q1 is activated, causing the first MOS transistor Q1 to conduct, and the level port outputs a low level. If no LED is connected, no voltage can be detected on the detection port, the first MOS transistor Q1 is turned off, and the level port outputs a high-level signal.

2. The white light detection circuit according to claim 1, characterized in that: It also includes a first resistor R1, one end of which is connected to the drain of the first MOSFET Q1, and the other end is connected to the power module.

3. The white light detection circuit according to claim 1, characterized in that: It also includes a second resistor R2, one end of which is connected to the node between the drain of the first MOSFET Q1 and the power module, and the other end is connected to the level port.

4. A white light detection system, characterized in that: The white light detection circuit includes any one of claims 1-3, and further includes a power supply module and a red light R circuit, a green light G circuit, a blue light B circuit, and a white light W circuit connected in parallel. The power supply module is connected to the red light R circuit, the green light G circuit, the blue light B circuit, and the white light W circuit to provide power. The detection port in the white light detection circuit is connected to the white light W circuit and detects the first level signal on the white light W circuit when the light strip outputs white light to output a corresponding detection signal.

5. A white light detection system according to claim 4, characterized in that: It also includes an MCU module, which is connected to the level port to receive a second level signal and determines whether to connect the white light W based on the second level signal.

6. A white light detection system according to claim 4, characterized in that: It also includes a connection module, which is connected to the red light R circuit, green light G circuit, blue light B circuit, white light W circuit and white light detection circuit respectively. The connection module is used to connect the red light R circuit, green light G circuit, blue light B circuit, white light W circuit and white light detection circuit to subsequent equipment.

Images