A power-down shutter protection circuit and device

Abstract

The utility model discloses a kind of power-down shutter protection circuit and equipment, it is related to shutter protection technical field, the power-down shutter protection circuit includes shutter drive circuit, energy storage circuit, controller and power supply, the shutter drive circuit the energy storage circuit and the controller with the power supply connection, the shutter drive circuit is connected with the controller, the shutter drive circuit and the energy storage circuit are used to be connected with shutter, when the power supply normal power-on, the shutter drive circuit is used to open or close the shutter according to the control instruction of the controller, when the power supply abnormal power-down, the energy storage circuit is used to close the shutter. That is, the utility model can solve the technical problem that existing equipment cannot close shutter when encountering abnormal power-down by setting energy storage circuit, avoid infrared detector damage.

Description

Technical Field

[0001] This utility model relates to the field of shutter protection technology, and in particular to a power-off shutter protection circuit and device. Background Technology

[0002] Uncooled infrared detectors are thermally sensitive infrared detectors that operate without cryogenic cooling devices. Their core advantages include low cost, small size, low power consumption, and fast startup. Even when not in operation, they must be protected from direct sunlight and lasers. They are primarily used in infrared vehicle driver assistance systems, infrared aiming scopes, infrared handheld devices, and infrared night vision goggles. In this system, infrared electromagnetic waves radiated from the external scene are focused onto the infrared detector's sensitive array through a lens. A shutter is installed between the lens and the infrared detector. The product uses the shutter to control the flow of electromagnetic light onto the infrared detector's photosensitive array. The shutter automatically closes when the product is powered off to protect the infrared detector from damage caused by high heat sources, thus extending the product's lifespan.

[0003] In existing technologies, devices typically control the opening and closing of the shutter through a controller and a shutter drive circuit. However, when the device experiences an abnormal power outage, the controller and shutter drive circuit will fail, preventing the shutter from closing. This results in the continuous exposure of the infrared detector's photosensitive element, potentially causing irreversible damage to the photosensitive element and reducing the lifespan of the infrared detector. Utility Model Content

[0004] This utility model provides a power-off shutter protection circuit and device to solve the technical problem in the related art that existing devices cannot close the shutter when encountering abnormal power failure.

[0005] A power-off shutter protection circuit is provided, characterized in that it includes: a shutter drive circuit, an energy storage circuit, a controller, and a power supply; The shutter drive circuit, the energy storage circuit, and the controller are connected to the power supply. The shutter drive circuit is connected to the controller. The shutter drive circuit and the energy storage circuit are used to connect to the shutter. When the power supply is powered on normally, the shutter drive circuit is used to open or close the shutter according to the control command of the controller; When the power supply fails, the energy storage circuit is used to close the shutter.

[0006] In some embodiments, the energy storage circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first energy storage capacitor, a first control switch, and a second control switch; The first end of the first resistor is connected to the positive terminal of the power supply, the second end of the first resistor is connected to the first end of the first energy storage capacitor and the first end of the first control switch, the second end of the first control switch is connected to the shutter, and the second end of the first energy storage capacitor is grounded. The first end of the second resistor is connected to the positive terminal of the power supply, the second end of the second resistor is connected to the third end of the first control switch and the first end of the third resistor, and the second end of the third resistor is grounded. The first terminal of the second control switch is grounded, the second terminal of the second control switch is connected to the shutter, the third terminal of the second control switch is connected to the second terminal of the fourth resistor, and the first terminal of the fourth resistor is connected to the second terminal of the first control switch.

[0007] In some embodiments, the energy storage circuit further includes a second energy storage capacitor connected in parallel with the first energy storage capacitor.

[0008] In some embodiments, the energy storage circuit further includes a first diode, the anode of which is connected to the anode of the power supply, and the cathode of which is connected to the first terminal of the first resistor.

[0009] In some embodiments, the energy storage circuit further includes a second diode, the positive terminal of which is connected to the second terminal of the first control switch, and the negative terminal of which is connected to the shutter.

[0010] In some embodiments, the first control switch and the second control switch are MOSFETs.

[0011] In some embodiments, the first control switch and the second control switch are transistors.

[0012] In some embodiments, the shutter drive circuit includes a shutter drive chip connected to the controller and the shutter.

[0013] In some embodiments, the shutter drive circuit further includes a fifth resistor, a third capacitor, and a fourth capacitor. The first end of the fifth resistor is connected to the positive terminal of the power supply and the shutter drive chip, and the second end of the fifth resistor is connected to the shutter drive chip. The first end of the third capacitor is connected to the first end of the fifth resistor, and the second end of the third capacitor is grounded. The first end of the fourth capacitor is connected to the positive terminal of the power supply and the shutter drive chip, and the second end of the fourth capacitor is grounded.

[0014] Secondly, a device is provided, including the aforementioned shutter protection circuit.

[0015] The beneficial effects of the technical solution provided by this utility model include: This utility model provides a power-down shutter protection circuit and device. The power-down shutter protection circuit includes a shutter drive circuit, an energy storage circuit, a controller, and a power supply. The shutter drive circuit, the energy storage circuit, and the controller are connected to the power supply. The shutter drive circuit is connected to the controller. The shutter drive circuit and the energy storage circuit are used to connect to the shutter. When the power supply is normally powered on, the shutter drive circuit is used to open or close the shutter according to the control command of the controller. When the power supply fails, the energy storage circuit is used to close the shutter. In other words, this utility model, by incorporating an energy storage circuit, can solve the technical problem of existing devices being unable to close the shutter when encountering abnormal power failure, thus preventing damage to the infrared detector. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of a power-off shutter protection circuit provided for an embodiment of this utility model; Figure 2 A circuit diagram of the energy storage circuit provided for an embodiment of this utility model; Figure 3 Timing diagrams of shutter operation before and after abnormal power failure provided for embodiments of this utility model; Figure 4 A circuit diagram of the shutter drive circuit provided in an embodiment of this utility model. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] This utility model provides a power-off shutter protection circuit, which can solve the technical problem that existing equipment cannot close the shutter when encountering abnormal power failure.

[0020] See Figure 1As shown in the figure, this utility model embodiment provides a power-off shutter protection circuit, including: a shutter drive circuit, an energy storage circuit, a controller, and a power supply.

[0021] The shutter drive circuit, the energy storage circuit, and the controller are connected to the power supply. The shutter drive circuit is connected to the controller. The shutter drive circuit and the energy storage circuit are used to connect to the shutter.

[0022] When the power supply is powered on normally, the shutter drive circuit is used to open or close the shutter according to the control command of the controller.

[0023] When the power supply fails, the energy storage circuit is used to close the shutter.

[0024] The power-off shutter protection circuit in this embodiment of the utility model is equipped with an energy storage circuit. The energy storage circuit can close the shutter when the power supply fails abnormally, solving the technical problem that existing equipment cannot close the shutter when encountering abnormal power failure, and avoiding damage to the infrared detector.

[0025] As an optional implementation, in one embodiment of the utility model, see [link to utility model description]. Figure 2 As shown, the energy storage circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first energy storage capacitor C1, a first control switch V1, and a second control switch V2.

[0026] The first terminal of the first resistor R1 is connected to the positive terminal VDD of the power supply. The second terminal of the first resistor R1 is connected to the first terminal of the first energy storage capacitor C1 and the first terminal of the first control switch V1. The second terminal of the first control switch V1 is connected to the shutter. The second terminal of the first energy storage capacitor C1 is grounded. When the power supply fails, the electrical energy stored in the first energy storage capacitor C1 discharges the shutter. At this time, the current flows from SHUTTER- to SHUTTER+, and the shutter closes.

[0027] The first end of the second resistor R2 is connected to the positive terminal VDD of the power supply, the second end of the second resistor R2 is connected to the third end of the first control switch V1 and the first end of the third resistor R3, and the second end of the third resistor R3 is grounded.

[0028] The first terminal of the second control switch V2 is grounded, the second terminal of the second control switch is connected to the shutter, the third terminal of the second control switch V2 is connected to the second terminal of the fourth resistor R4, and the first terminal of the fourth resistor R4 is connected to the second terminal of the first control switch V1.

[0029] In this configuration, the first control switch V1 and the second control switch V2 are either MOSFETs or transistors. Taking the first control switch V1 and the second control switch V2 as MOSFETs, the gate of the first control switch V1 is connected to the second terminal of the second resistor R2, the source of the first control switch V1 is connected to the second terminal of the first resistor R1, and the drain of the first control switch V1 is connected to the shutter. The gate of the second control switch V2 is connected to the second terminal of the fourth resistor R4, the source of the second control switch V2 is grounded, and the drain of the second control switch V2 is connected to the shutter.

[0030] Specifically, see Figure 3 As shown, when the power supply is normally powered on, the gate of the first control switch V1 is at a high level, the source and drain of the first control switch V1 are not connected, the drain and source of the second control switch V2 are not connected, the first energy storage capacitor C1 is isolated from the shutter drive circuit, and the shutter drive circuit can normally control the shutter to close and open. When the power supply fails, the shutter drive circuit does not work. The source and drain of the first control switch V1 are connected, the drain and source of the second control switch V2 are connected, the first energy storage capacitor C1 directly discharges to the shutter, the current flows from SHUTTER- to SHUTTER+, and the shutter closes. The energy storage circuit realizes the shutter closing after a power failure through a pure hardware circuit, which is simple and highly reliable.

[0031] As an optional implementation, in one embodiment of the utility model, see [link to utility model description]. Figure 2 As shown, the energy storage circuit also includes a second energy storage capacitor C2, which is connected in parallel with the first energy storage capacitor C1. Specifically, the second energy storage capacitor C2 can be further connected in parallel with the first energy storage capacitor C1 to form a combined energy storage capacitor, satisfying the actual shutter closing requirements. Generally, the combined energy storage capacitor is matched to the shutter load: 0.5·C·U·U (energy storage capacitor energy) = 0.5·U·U·t / R (energy released by the shutter coil), where C is the combined energy storage capacitor value, U is the shutter operating voltage, t is the shutter discharge time, and R is the shutter coil internal resistance. If the shutter coil internal resistance in the circuit is 16.5Ω, and the manufacturer recommends a high-level duration of 15ms for shutter opening or closing, the combined energy storage capacitor C = 1800uF. Considering reliability design, the combined energy storage capacitor can be designed with 20% redundancy.

[0032] As an optional implementation, in one embodiment of the utility model, see [link to utility model description]. Figure 2 As shown, the energy storage circuit also includes a first diode D1, the anode of the first diode D1 is connected to the anode of the power supply, and the cathode of the first diode D1 is connected to the first terminal of the first resistor R1.

[0033] As an optional implementation, in one embodiment of the utility model, see [link to utility model description]. Figure 2 As shown, the energy storage circuit also includes a second diode D2, the positive terminal of which is connected to the second terminal of the first control switch V1, and the negative terminal of which is connected to the shutter.

[0034] As an optional implementation, in one embodiment of the utility model, see [link to utility model description]. Figure 4 As shown, the shutter drive circuit includes a shutter drive chip U1, which is connected to the controller and the shutter. Specifically, pins IN1 and IN2 of the shutter drive chip U1 are connected to the controller, and pins OUT1 and OUT2 of the shutter drive chip U1 are connected to the shutter.

[0035] Furthermore, the shutter drive circuit also includes a fifth resistor R5, a third capacitor C3, and a fourth capacitor C4. The first end of the fifth resistor R5 is connected to the positive terminal of the power supply and the shutter drive chip U1, and the second end of the fifth resistor R5 is connected to the shutter drive chip U1. The first end of the third capacitor C3 is connected to the first end of the fifth resistor R5, and the second end of the third capacitor C3 is grounded. The first end of the fourth capacitor C4 is connected to the positive terminal of the power supply and the shutter drive chip U1, and the second end of the fourth capacitor C4 is grounded.

[0036] Specifically, the first end of the fifth resistor R5 is connected to the positive terminal of the power supply and the VCC pin of the shutter driver chip U1, and the second end of the fifth resistor R5 is connected to the nSLEEP pin of the shutter driver chip U1. The first end of the fourth capacitor C4 is connected to the positive terminal of the power supply and the VM pin of the shutter driver chip U1. When the power supply is powered on normally, the controller sends control commands to the IN1 and IN2 pins of the shutter driver chip U1. The shutter driver chip U1 controls the shutter to open or close through the OUT1 and OUT2 pins. When the current flows from SHUTTER- to SHUTTER+, the shutter closes; when the current flows from SHUTTER+ to SHUTTER-, the shutter opens.

[0037] The operating logic of the shutter drive circuit is shown in Table 1 below: Table 1

[0038] This utility model embodiment also provides a device, including the aforementioned power-off shutter protection circuit.

[0039] In the description of this utility model, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0040] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A power-off shutter protection circuit, characterized in that, include: Shutter drive circuit, energy storage circuit, controller and power supply; The shutter drive circuit, the energy storage circuit, and the controller are connected to the power supply. The shutter drive circuit is connected to the controller. The shutter drive circuit and the energy storage circuit are used to connect to the shutter. When the power supply is powered on normally, the shutter drive circuit is used to open or close the shutter according to the control command of the controller; When the power supply fails, the energy storage circuit is used to close the shutter.

2. The power-off shutter protection circuit according to claim 1, characterized in that: The energy storage circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first energy storage capacitor, a first control switch, and a second control switch; The first end of the first resistor is connected to the positive terminal of the power supply, the second end of the first resistor is connected to the first end of the first energy storage capacitor and the first end of the first control switch, the second end of the first control switch is connected to the shutter, and the second end of the first energy storage capacitor is grounded. The first end of the second resistor is connected to the positive terminal of the power supply, the second end of the second resistor is connected to the third end of the first control switch and the first end of the third resistor, and the second end of the third resistor is grounded. The first terminal of the second control switch is grounded, the second terminal of the second control switch is connected to the shutter, the third terminal of the second control switch is connected to the second terminal of the fourth resistor, and the first terminal of the fourth resistor is connected to the second terminal of the first control switch.

3. The power-off shutter protection circuit according to claim 2, characterized in that: The energy storage circuit also includes a second energy storage capacitor, which is connected in parallel with the first energy storage capacitor.

4. The power-off shutter protection circuit according to claim 2, characterized in that: The energy storage circuit further includes a first diode, the anode of which is connected to the anode of the power supply, and the cathode of which is connected to the first terminal of the first resistor.

5. The power-off shutter protection circuit according to claim 2, characterized in that: The energy storage circuit also includes a second diode, the positive terminal of which is connected to the second terminal of the first control switch, and the negative terminal of which is connected to the shutter.

6. The power-off shutter protection circuit according to claim 2, characterized in that: The first control switch and the second control switch are MOSFETs.

7. The power-off shutter protection circuit according to claim 2, characterized in that: The first control switch and the second control switch are transistors.

8. The power-off shutter protection circuit according to claim 1, characterized in that: The shutter drive circuit includes a shutter drive chip, which is connected to the controller and the shutter.

9. The power-off shutter protection circuit according to claim 8, characterized in that: The shutter drive circuit further includes a fifth resistor, a third capacitor, and a fourth capacitor. The first end of the fifth resistor is connected to the positive terminal of the power supply and the shutter drive chip. The second end of the fifth resistor is connected to the shutter drive chip. The first end of the third capacitor is connected to the first end of the fifth resistor, and the second end of the third capacitor is grounded. The first end of the fourth capacitor is connected to the positive terminal of the power supply and the shutter drive chip, and the second end of the fourth capacitor is grounded.

10. A device, characterized in that, Includes the power-off shutter protection circuit as described in any one of claims 1-9.

Images