Infrared white light lamp control circuit and monitoring camera

Abstract

The utility model relates to monitoring camera technical field discloses an infrared white light lamp control circuit and monitoring camera, wherein control circuit includes drive control chip, power supply circuit, output circuit, first electronic switch and second electronic switch. Wherein the input of power supply circuit is connected with external power supply, and the output is connected with the power supply pin of drive control chip. The input of output circuit is connected with the output pin of drive control chip, and the output is connected with the anode of infrared lamp pearl and white light lamp pearl. The input and output of first electronic switch are connected with the cathode of infrared lamp pearl and the feedback pin of drive control chip respectively, and the control end is connected with infrared control signal. The input and output of second electronic switch are connected with the cathode of white light lamp pearl and the feedback pin of drive control chip respectively, and the control end is connected with white light control signal. The control circuit can reduce the size of control circuit board, facilitate the centralized heat dissipation of radiator and improve the stability of camera.

Description

Technical Field

[0001] This utility model relates to the field of surveillance camera technology, specifically to an infrared white light control circuit and a surveillance camera. Background Technology

[0002] As people's living standards improve, more and more families are installing and using IP cameras and other surveillance cameras. To obtain clear images under different lighting conditions, surveillance cameras often have internal white light illumination for supplemental lighting and infrared illumination for capturing nighttime images. In existing surveillance cameras, the white light LEDs and infrared LEDs are often controlled by two separate sets of control circuits. This results in a larger circuit board area, making it difficult for the heat sink to simultaneously cover the heat dissipation of both the white light and infrared LEDs. Furthermore, since infrared LEDs generate more heat, this can lead to localized overheating, affecting the operation of the temperature-sensitive white light LEDs and thus impacting the stability of the camera during long-term operation. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide an infrared white light control circuit that can centrally control the infrared LEDs and white light LEDs in the camera, thereby reducing the area of ​​the control circuit board, enabling the heat sink to centrally dissipate heat from the circuit board, avoiding local overheating that could affect the normal operation of the surveillance camera, and improving the stability of the camera's operation.

[0004] To solve the above problems, the technical solution adopted by this utility model is as follows: an infrared white light lamp control circuit, comprising: a drive control chip; a power supply circuit, the input end of which is connected to an external power supply, and the output end of which is connected to the power supply pin of the drive control chip; an output circuit, the input end of which is connected to the output pin of the drive control chip, and the output end of which is connected to the positive terminals of the infrared lamp bead and the white light lamp bead; a first electronic switch, the input end of which is connected to the negative terminal of the infrared lamp bead and the feedback pin of the drive control chip respectively, and the control terminal of which receives an infrared control signal; and a second electronic switch, the input end of which is connected to the negative terminal of the white light lamp bead and the feedback pin of the drive control chip respectively, and the control terminal of which receives a white light control signal.

[0005] Compared to existing technologies, the advantages of this invention are as follows: Independent control of the infrared and white LEDs is achieved through a single drive control chip and two electronic switches, reducing the number of chips and components in the control circuit. This results in a smaller control circuit board size and reduced heat dissipation area requirements. The reduced circuit board size allows for a more compact placement of the infrared and white LEDs, concentrating heat and facilitating unified cooling of both LEDs by the heat sink. This prevents localized overheating from affecting camera operation and improves camera stability.

[0006] In the aforementioned infrared white light control circuit, both the first electronic switch and the second electronic switch are NMOS transistors. The gates of the first electronic switch and the second electronic switch are respectively connected to the infrared control signal and the white light control signal. The sources of both the first electronic switch and the second electronic switch are connected to the feedback pin of the drive control chip. The drain of the first electronic switch is connected to the negative terminal of the infrared lamp bead, and the drain of the second electronic switch is connected to the negative terminal of the white light lamp bead.

[0007] The infrared white light control circuit described above includes a power supply circuit comprising capacitor C104, capacitor C107, and inductor L7. The first ends of capacitors C104 and C107 are connected to the external power supply and the input pin of the drive control chip, respectively. The second ends of capacitors C104 and C107 are grounded. The two ends of inductor L7 are connected to the input pin and the output pin of the drive control chip, respectively.

[0008] The aforementioned infrared white light control circuit includes an output circuit comprising capacitor C105, capacitor C106, and diode D14. The anode of diode D14 is connected to the output pin of the drive control chip. The first terminals of capacitors C105 and C106 are connected to the cathode of diode D14, the anode of the infrared LED, and the anode of the white light LED. The second terminals of capacitors C105 and C106 are grounded.

[0009] In the aforementioned infrared white light control circuit, the feedback pin of the drive control chip is grounded through the current detection resistor R79.

[0010] In the aforementioned infrared white light control circuit, the enable pin of the drive control chip is connected to the total control signal through a first voltage divider circuit composed of resistors R80 and R72. The total control signal is formed by the parallel connection of the infrared control signal and the white light control signal. The first end of resistor R80 is connected to the total control signal, the second end of resistor R80 is connected to the enable pin of the drive control chip, the first end of resistor R72 is connected to the enable pin of the drive control chip, and the second end of resistor R72 is grounded.

[0011] In the aforementioned infrared white light control circuit, the control terminal of the first electronic switch is connected to the infrared control signal through a second voltage divider circuit composed of resistors R82 and R81. The first end of resistor R82 is connected to the infrared control signal, the second end of resistor R82 is connected to the control terminal of the first electronic switch, the first end of resistor R81 is connected to the control terminal of the first electronic switch, and the second end of resistor R81 is grounded.

[0012] In the aforementioned infrared white light control circuit, the control terminal of the second electronic switch is connected to the white light control signal through a third voltage divider circuit composed of resistors R84 and R83. The first end of resistor R84 is connected to the white light control signal, the second end of resistor R84 is connected to the control terminal of the second electronic switch, the first end of resistor R83 is connected to the control terminal of the second electronic switch, and the second end of resistor R83 is grounded.

[0013] The aforementioned infrared white light control circuit uses an STI9287 chip as its driving control chip.

[0014] A surveillance camera includes the aforementioned infrared white light control circuit.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the infrared white light control circuit according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the infrared white light control circuit according to an embodiment of the present invention. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below, with reference to Figure 1Therefore, this utility model provides an infrared white light control circuit, including a driver control chip, a power supply circuit, an output circuit, a first electronic switch, and a second electronic switch. The input terminal of the power supply circuit is connected to an external power supply, which in this embodiment is connected to the battery of a surveillance camera. The output terminal of the power supply circuit is connected to the power supply pin of the driver control chip. The input terminal of the output circuit is connected to the output pin of the driver control chip, and the output terminal is connected to the positive terminals of the infrared LED and the white light LED. The input and output terminals of the first electronic switch are respectively connected to the negative terminal of the infrared LED and the feedback pin of the driver control chip, and the control terminal receives an infrared control signal. The input and output terminals of the second electronic switch are respectively connected to the negative terminal of the white light LED and the feedback pin of the driver control chip, and the control terminal receives a white light control signal. This infrared white light control circuit establishes a first electronic switch and a second electronic switch between the negative terminal of the infrared LED and the feedback pin of the driver control chip, and between the negative terminal of the white light LED and the feedback pin of the driver control chip, respectively. The first and second electronic switches are controlled by infrared control signals and white light control signals, respectively, to form a closed power supply circuit for the infrared and white light LEDs, thus achieving independent control of the infrared and white light LEDs. This control circuit achieves independent control of the infrared and white light LEDs with only one driver control chip and two electronic switches. Compared to using two separate control circuits, this reduces the number of chips and their peripheral circuits, thereby reducing the area of ​​the control board. This allows for a more concentrated placement of the infrared and white light LEDs, resulting in more concentrated heat dissipation from the board. This coordinated thermal management of the heat generated by the infrared and white light LEDs improves the operational stability of the surveillance camera and prevents localized overheating.

[0019] It is understandable that the driver control chip can be an LED driver chip, referring to... Figure 2In this embodiment, the drive control chip U12 is an STI9287 series LED driver chip from Tuoer Microelectronics. The power supply circuit includes capacitors C104 and C107 and inductor L7. The first terminals of capacitors C104 and C107 are both connected to the battery power supply, and the second terminals of both capacitors C104 and C107 are grounded. The two terminals of inductor L7 are connected to the input pin 6 and output pin 4 of the drive control chip U12, respectively. Capacitors C104 and C107, and inductor L7 form a filter circuit to filter out ripple in the power supply and provide a stable DC voltage for the control circuit. In this embodiment, the output circuit includes capacitors C105 and C106 and diode D14. The anode of diode D14 is connected to the output pin 4 of the drive control chip U12, and the cathode of diode D14 is connected to the anodes of the infrared and white LED beads. Diode D14 is a fast recovery diode to prevent inductor L7 from being reverse-biased. The first terminals of capacitors C105 and C106 are connected to the negative terminal of diode D14, the positive terminal of infrared LED, and the positive terminal of white LED. The second terminals of capacitors C105 and C106 are grounded. Capacitors C105 and C106 are used to filter the output voltage, reduce output ripple, and improve the brightness stability of infrared and white light.

[0020] It is understandable that the first and second electronic switches can be transistors or triodes. (Refer to...) Figure 2In this embodiment, both the first and second electronic switches are NMOS transistors. The enable pin 5 of the drive control chip U12, the gate of the first electronic switch QW3, and the gate of the second electronic switch QW4 are all connected to the corresponding control signals via a voltage divider circuit composed of resistors. The control signals can be PWM signals or a high-level enable signal. The enable pin 5 of the drive control chip U12 is connected to the total control signal via resistor R80. One end of resistor R80 connected to the enable pin 5 is grounded via resistor R72. The total control signal can be a control signal composed of a parallel connection of an infrared control signal and a white light control signal. When either the infrared LED or the white light LED needs to be enabled, the drive control chip U12 is enabled. The gate of the first electronic switch QW3 is connected to the infrared control signal through resistor R82. One end of resistor R82 connected to the gate of the first electronic switch QW3 is grounded through resistor R81. The source of the first electronic switch QW3 is connected to feedback pin 1 of the drive control chip U12, and the drain of the first electronic switch QW3 is connected to the negative terminal of the infrared LED. When the infrared control signal is high, the first electronic switch QW3 connects the infrared LED and the drive control chip U12 to form a closed power supply circuit, causing the infrared LED to start working. Similarly, the gate of the second electronic switch QW4 is connected to the white light control signal through resistor R84. One end of resistor R84 connected to the gate of the second electronic switch QW4 is grounded through resistor R83. The source of the second electronic switch QW4 is connected to feedback pin 1 of the drive control chip U12, and the drain of the second electronic switch QW4 is connected to the negative terminal of the white light LED. (Refer to...) Figure 2 In this embodiment, the feedback pin 1 of the drive control chip U12 is also grounded through the current detection resistor R79. The current flowing through the LED lamp bead load is detected by the voltage of the current detection resistor R79, thereby realizing overcurrent protection for the infrared lamp bead and the white lamp bead, and preventing the infrared lamp bead or the white lamp bead from being burned by the large current under abnormal conditions.

[0021] Based on the same inventive concept, this utility model embodiment also provides a surveillance camera, including the aforementioned infrared white light control circuit. The infrared white light control circuit, infrared LEDs, and white LEDs are all mounted on a single circuit board, with a heat sink on the back side of the circuit board. Because the infrared LEDs and white LEDs are controlled by a single driver control chip and its peripheral circuitry, the circuit area and circuit board area are small. This allows the infrared LEDs and white LEDs to be centrally mounted on the circuit board, facilitating simultaneous heat sink coverage of the back sides of both LEDs. This enables coordinated thermal management of the infrared LEDs and white LEDs, preventing localized overheating that could affect the normal operation of the camera and allowing for more stable long-term operation.

[0022] It should be noted that in the description of this utility model, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this utility model.

[0023] In the description of this utility model, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is mentioned, it is only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0025] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. An infrared white light lamp control circuit, characterized in that, include: Drive control chip; The power supply circuit has its input terminal connected to an external power supply and its output terminal connected to the power supply pin of the drive control chip. The output circuit has its input terminal connected to the output pin of the drive control chip, and its output terminal connected to the positive terminals of the infrared LED and the white LED. The first electronic switch has its input and output terminals connected to the negative electrode of the infrared lamp bead and the feedback pin of the drive control chip, respectively, and its control terminal receives an infrared control signal. The second electronic switch has its input and output terminals connected to the negative terminal of the white LED bead and the feedback pin of the drive control chip, respectively, and its control terminal receives the white light control signal.

2. The infrared white light lamp control circuit according to claim 1, characterized in that, Both the first electronic switch and the second electronic switch are NMOS transistors. The gates of the first electronic switch and the second electronic switch are respectively connected to the infrared control signal and the white light control signal. The sources of both the first electronic switch and the second electronic switch are connected to the feedback pin of the drive control chip. The drain of the first electronic switch is connected to the negative terminal of the infrared lamp bead, and the drain of the second electronic switch is connected to the negative terminal of the white light lamp bead.

3. The infrared white light lamp control circuit according to claim 1, characterized in that, The power supply circuit includes capacitor C104, capacitor C107 and inductor L7. The first ends of capacitors C104 and C107 are connected to the external power supply and the input pin of the drive control chip, respectively. The second ends of capacitors C104 and C107 are grounded. The two ends of inductor L7 are connected to the input pin and the output pin of the drive control chip, respectively.

4. The infrared white light lamp control circuit according to claim 1, characterized in that, The output circuit includes capacitors C105 and C106 and diode D14. The anode of diode D14 is connected to the output pin of the drive control chip. The first terminals of capacitors C105 and C106 are connected to the cathode of diode D14, the anode of infrared LED, and the anode of white LED. The second terminals of capacitors C105 and C106 are grounded.

5. The infrared white light lamp control circuit according to claim 1, characterized in that, The feedback pin of the drive control chip is grounded through the current sensing resistor R79.

6. The infrared white light lamp control circuit according to claim 1, characterized in that, The enable pin of the drive control chip is connected to the total control signal through a first voltage divider circuit composed of resistors R80 and R72. The total control signal is formed by the parallel connection of the infrared control signal and the white light control signal. The first end of resistor R80 is connected to the total control signal, the second end of resistor R80 is connected to the enable pin of the drive control chip, the first end of resistor R72 is connected to the enable pin of the drive control chip, and the second end of resistor R72 is grounded.

7. The infrared white light lamp control circuit according to claim 1, characterized in that, The control terminal of the first electronic switch is connected to the infrared control signal through a second voltage divider circuit composed of resistors R82 and R81. The first end of resistor R82 is connected to the infrared control signal, the second end of resistor R82 is connected to the control terminal of the first electronic switch, the first end of resistor R81 is connected to the control terminal of the first electronic switch, and the second end of resistor R81 is grounded.

8. The infrared white light lamp control circuit according to claim 1, characterized in that, The control terminal of the second electronic switch is connected to the white light control signal through a third voltage divider circuit composed of resistors R84 and R83. The first end of resistor R84 is connected to the white light control signal, the second end of resistor R84 is connected to the control terminal of the second electronic switch, the first end of resistor R83 is connected to the control terminal of the second electronic switch, and the second end of resistor R83 is grounded.

9. The infrared white light lamp control circuit according to any one of claims 1 to 8, characterized in that, The drive control chip is an STI9287 chip.

10. A surveillance camera, characterized in that, Includes the infrared white light control circuit according to any one of claims 1 to 9.

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