Load detection circuit and lighting device

Abstract

The present application relates to a load detection circuit and a lighting device, wherein the load detection circuit comprises: a sampling module, the sampling module is used to connect to the load, and the sampling module is configured to output a sampling voltage when a driving power supply is connected to the load; an output module, the output module is configured to output a corresponding detection signal according to the sampling voltage at the output end of the sampling module after receiving a start signal; a current control module, the current control module is used to limit the current outputted from the sampling module to the ground end; the current control module is also configured to be turned on or off according to a switch control signal; after the start signal is transmitted to the output module, the switch control signal is transmitted to the current control module. Through the present application, it is possible to detect whether the load is connected to the driving power supply when only a weak current passes through the load. At the same time, when the output module outputs a detection signal, the current control module can be automatically and completely turned off, so that the power consumption of the load detection circuit is reduced to 0.

Description

Technical Field

[0001] The present application belongs to the technical field of detection circuits, and in particular, relates to a load detection circuit and a lighting device. Background Art

[0002] At present, in traditional load driving circuits, it is often necessary to detect whether a load is connected to a power supply to ensure that when driving the load, the driving voltage output by the power supply cannot be transmitted to the load because the load is not successfully connected to the power supply.

[0003] Especially for a lighting system, whether the light-emitting module is successfully connected to the power supply plays a very important role in indicating the setting of the lighting mode of the lighting system.

[0004] Conventional detection circuits for whether the load is successfully connected to the power supply usually require that the load and the power supply form a complete loop, so that the load is in operation and a large current flows through the load before detection can be performed, which will directly cause the light-emitting module of the lighting system to light up directly, thereby affecting the normal operation of the lighting system. Conventional detection circuits are usually unable to automatically close the detection loop after the detection is completed, resulting in continuous power consumption of the detection circuit. Summary of the invention

[0005] The purpose of the present application is to provide a load detection circuit and a lighting device, aiming to solve the problem of continuous power consumption of the detection circuit existing in the traditional detection circuit.

[0006] A first aspect of an embodiment of the present application provides a load detection circuit, comprising: a sampling module, wherein the input end of the sampling module is used to connect to a load, and the sampling module is configured to output a sampling voltage when a driving power supply is connected to the load; an output module, wherein the input end of the output module is connected to the output end of the sampling module, and the output module is configured to output a corresponding detection signal according to the sampling voltage at the output end of the sampling module after receiving a start signal; a current control module, wherein the current control module is arranged between the output end of the sampling module and a ground end, and the current control module is used to limit the current output by the sampling module to the ground end; the current control module is also configured to be turned on or off according to a switch control signal; the start signal is first transmitted to the output module, and then transmitted to the current control module after the switch control signal for turning off the current control module is transmitted to the current control module, so as to ensure that the output module can output the detection signal before the current control module is turned off.

[0007] In one embodiment, a detection control module is further included, which is connected to the current control module and the output module respectively, and the detection control module is configured to output the start signal and output the switch control signal for shutting down the current control module to the current control module according to the start signal.

[0008] In one embodiment, the sampling module includes a first current limiting resistor, the first end of the first current limiting resistor is used to be connected to a load, the second end of the first current limiting resistor is the output end of the sampling module, and the sampling module is used to generate a corresponding sampling voltage at the second end of the first current limiting resistor when the load is connected to the driving power supply.

[0009] In one embodiment, the output module includes a first amplifying and shaping unit and a trigger, the input end of the first amplifying and shaping unit is connected to the output end of the sampling module, the output end of the first amplifying and shaping unit is connected to the first input end of the trigger, and the second input end of the trigger is used to receive the start signal; the first amplifying and shaping unit is configured to generate a corresponding sampling level according to the sampling voltage at the output end of the sampling module, and the trigger is configured to output the sampling level as the detection signal when the second output end of the trigger receives the start signal.

[0010] In one embodiment, the first amplifying and shaping unit includes a first inverter and a second inverter, the input end of the first inverter is connected to the output end of the sampling module, the output end of the first inverter is connected to the input end of the second inverter, and the output end of the second inverter is connected to the first input end of the trigger.

[0011] In one embodiment, the current control module includes a switch tube and a current limiting unit, the first conduction end of the switch tube is connected to the output end of the sampling module, the second conduction end of the switch tube is connected to the input end of the current limiting unit, the output end of the current limiting unit is connected to the ground end, the controlled end of the switch tube is used to receive the switch control signal, the switch tube is configured to be turned on or off according to the switch control signal, and the current limiting unit is used to limit the current transmitted from the current control module to the ground end.

[0012] In one embodiment, the current limiting unit includes a current limiting tube, a first conduction end of the current limiting tube is connected to the second conduction end of the switch tube, the second conduction end of the current limiting tube is connected to the ground end, and the current limiting tube remains turned off to allow only a micro current to pass through the current limiting tube.

[0013] In one embodiment, the detection control module includes a control unit, and the control unit is respectively connected to the output module and the current control module to output the start signal and the switch control signal respectively.

[0014] In one embodiment, the detection control module includes a starting power supply, a second amplifying and shaping unit and an inverting unit, the starting power supply is connected to the input end of the second amplifying and shaping unit, the output end of the second amplifying and shaping unit is connected to the output module, so as to output the starting signal to the output module when the starting power supply outputs a voltage; the second amplifying and shaping unit is also connected to the input end of the inverting unit, and the output end of the inverting unit is connected to the current control module, so as to output the switch control signal to the current control module according to the starting signal.

[0015] A second aspect of an embodiment of the present application provides a lighting device, comprising a lighting module and a load detection circuit as described above, wherein the load detection circuit is connected to the lighting module to detect whether the lighting module is successfully connected to the driving power supply.

[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: after the output module outputs the detection signal, the current control module can be automatically and completely shut down, so that the power consumption of the load detection circuit is reduced to 0. At the same time, the current output by the sampling module is limited by the current control module, so that the current in the loop composed of the sampling module, the current control module and the load is extremely small, but it is also enough for the output module to output the corresponding detection signal, so as to detect whether the load is connected to the driving power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A principle block diagram of a load detection circuit provided in the first embodiment of the present application;

[0018] Figure 2 A circuit diagram of a load detection circuit provided in the first embodiment of the present application;

[0019] Figure 3 A circuit diagram of a load detection circuit provided by another embodiment of the present application;

[0020] Figure 4 This is a principle block diagram of the lighting device provided in the second embodiment of the present application.

[0021] Description of the above drawings: 10, lighting module; 20, load detection circuit; 100, sampling module; 200, output module; 210, first amplifying and shaping unit; 300, current control module; 310, current limiting unit; 400, detection control module; 410, second amplifying and shaping unit; 420, inverting unit. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0024] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] Figure 1 The principle block diagram of the load detection circuit provided in the first embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0027] A load detection circuit 20 includes a sampling module 100 , an output module 200 and a current control module 300 .

[0028] Among them, the input end of the sampling module 100 is used to connect with the load RT, and the sampling module 100 is configured to output a sampling voltage when a driving power supply is connected to the load RT. The input end of the output module 200 is connected to the output end of the sampling module 100, and the output module 200 is configured to output a corresponding detection signal according to the sampling voltage at the output end of the sampling module 100 after receiving the start signal. The current control module 300 is arranged between the output end and the ground end of the sampling module 100. The current control module 300 is used to limit the current output from the sampling module 100 to the ground end, that is, to limit the current on the load RT to avoid excessive current on the load RT; the current control module 300 is also configured to be turned on or off according to the switch control signal. After the start signal is transmitted to the output module 200, the switch control signal for turning off the current control module 300 will be transmitted to the current control module 300, so as to ensure that the output module 200 can output the detection signal before the current control module 300 is turned off.

[0029] It should be noted that, after the load RT is connected to the driving power supply, the load RT can be connected to the ground terminal through the sampling module 100 and the current control module 300 in sequence, thereby forming a complete loop. At the same time, since the current control module 300 limits the current output by the sampling module 100, the current in the entire loop is extremely small. At the same time, after the start signal controls the output module 200 to output the corresponding detection signal, the switch control signal automatically turns off the current control module 300, so that the loop of the load RT is completely disconnected, and the static current becomes 0.

[0030] like Figure 2 As shown, in this embodiment, the load detection circuit 20 also includes a detection control module 400, which is respectively connected to the current control module 300 and the output module 200, and the detection control module 400 is configured to output a start signal and output a switch control signal to the current control module 300 according to the start signal.

[0031] like Figure 2 As shown, in this embodiment, the sampling module 100 includes a first current limiting resistor R1, the first end of the first current limiting resistor R1 is a sampling end, which is used to connect to the load RT, and the second end of the first current limiting resistor R1 is the output end of the sampling module 100. The sampling module 100 is used to generate a corresponding sampling voltage at the second end of the first current limiting resistor R1 when the load RT is connected to the driving power supply. The first current limiting resistor R1 can limit the current transmitted from the load RT to a certain extent, so as to protect the current control module 300 and prevent the current flowing into the current control module 300 from being too large.

[0032] like Figure 2As shown, in this embodiment, the sampling module 100 also includes a second current limiting resistor R2, which is arranged between the output end of the sampling module 100 and the output module 200. The first end of the second current limiting resistor R2 is connected to the output end of the sampling module 100, and the second end of the second current limiting resistor R2 is connected to the input end of the output module 200. The second current limiting resistor R2 is used to protect the output module 200 to prevent excessive current from flowing into the output module 200.

[0033] like Figure 2 As shown, in this embodiment, the output module 200 includes a first amplifying and shaping unit 210 and a trigger U6. The input end of the first amplifying and shaping unit 210 is the input end of the output module 200, which is used to connect to the sampling module 100. The output end of the first amplifying and shaping unit 210 is connected to the first input end of the trigger U6, and the second input end of the trigger U6 is used to receive a start signal. The first amplifying and shaping unit 210 is configured to generate a corresponding sampling level according to the sampling voltage at the output end of the sampling module 100. The trigger U6 is configured so that when the second output end of the trigger U6 receives the start signal, the output end OUT of the trigger U6 outputs the sampling level of the first input end as a detection signal. The trigger U6 can be a D trigger, the output end OUT of the trigger U6 is the Q end of the D trigger, the first input end is the D end of the D trigger, and the second input end is the clock input end of the D trigger.

[0034] Specifically, the first amplifying and shaping unit 210 includes a first inverter U1 and a second inverter U2, the input end of the first inverter U1 is connected to the sampling module 100 as the input end of the output module 200, the output end of the first inverter U1 is connected to the input end of the second inverter U2, and the output end of the second inverter U2 is connected to the first input end of the trigger U6.

[0035] It should be noted that when the load RT is not connected to the driving power supply, the sampling voltage is 0, then the output end of the first inverter U1 outputs a high level, and the output end of the second inverter U2 corresponds to the output of a low level. At this time, the sampling level is low, and the detection signal is also low. When the load RT is connected to the driving power supply, the sampling voltage increases, then the output end of the first inverter U1 outputs a low level, and the output end of the second inverter U2 corresponds to the output of a high level. At this time, the sampling level is high, and the detection signal is also high. This embodiment can ignore the specific parameters of the sampling voltage, realize the shaping and amplification of the sampling voltage, and can judge whether the load RT is connected to the driving power supply only by the sampling level.

[0036] like Figure 2As shown, in this embodiment, the current control module 300 includes a switch tube Q1 and a current limiting unit 310. The first conduction end of the switch tube Q1 is connected to the output end of the sampling module 100, the second conduction end of the switch tube Q1 is connected to the input end of the current limiting unit 310, the output end of the current limiting unit 310 is connected to the ground end, the controlled end of the switch tube Q1 is used to receive a switch control signal, the switch tube Q1 is configured to be turned on or off according to the switch control signal, and the current limiting unit 310 is used to limit the current transmitted from the current control module 300 to the ground end.

[0037] Specifically, the current limiting unit 310 includes a current limiting tube Q2, a first conduction terminal of the current limiting tube Q2 is connected to the second conduction terminal of the switch tube Q1, a second conduction terminal of the current limiting tube Q2 is connected to the ground terminal, and the current limiting tube Q2 remains turned off to allow only a micro current to pass through the current limiting tube Q2.

[0038] Among them, the switch tube Q1 can be an enhancement type NMOS tube, the current limiting tube Q2 can be a depletion type NMOS tube, and the controlled end of the current limiting tube Q2 is connected to the ground end. It should be noted that the controlled end of the depletion type NMOS tube connected to the ground end can still pass a micro-current of the micro-ampere level, that is, the current limiting tube Q2 always remains in the on state. In this embodiment, the first conduction end of the switch tube Q1 is the drain of the enhancement type NMOS tube, the second conduction end of the switch tube Q1 is the source of the enhancement type NMOS tube, and the controlled end of the switch tube Q1 is the gate of the enhancement type NMOS tube. The first conduction end of the current limiting tube Q2 is the drain of the depletion type NMOS tube, the second conduction end of the current limiting tube Q2 is the source of the depletion type NMOS tube, and the controlled end of the current limiting tube Q2 is the gate of the depletion type NMOS tube.

[0039] like Figure 2 As shown, in this embodiment, the detection control module 400 includes a startup power supply VIN, a second amplifying and shaping unit 410 and an inverting unit 420. The startup power supply VIN is connected to the input end of the second amplifying and shaping unit 410, and the output end of the second amplifying and shaping unit 410 is connected to the output module 200, so as to output a startup signal to the output module 200; the second amplifying and shaping unit 410 is also connected to the input end of the inverting unit 420, and the output end of the inverting unit 420 is connected to the current control module 300, so as to output a switch control signal to the current control module 300. The startup power supply VIN can be used to start the load RT, so that when the load RT is ready to be started, it is first detected whether the load RT is connected to the driving power supply.

[0040] Specifically, the second amplifying and shaping unit 410 includes a third inverter U3 and a fourth inverter U4, the input end of the third inverter U3 is connected to the startup power supply VIN, the output end of the third inverter U3 is connected to the input end of the fourth inverter U4, and the output end of the fourth inverter U4 is connected to the second input end of the trigger U6. The inverting unit 420 includes a fifth inverter U5, the input end of the fifth inverter U5 is connected to the output end of the fourth inverter U4, and the output end of the fifth inverter U5 is connected to the controlled end of the switch tube Q1.

[0041] It should be noted that when the startup power supply VIN does not output a voltage, the output end of the second amplifying and shaping unit 410 is at a low level, and the inverting unit 420 outputs a high-level switch control signal. At this time, the switch tube Q1 is turned on; after the switch tube Q1 is turned on, the first input end of the trigger U6 can receive the corresponding sampling level. When the startup power supply VIN outputs a voltage, the second amplifying and shaping unit 410 first outputs a high-level startup signal, so that the output end OUT of the trigger U6 outputs the sampling level (detection signal) of the first input end, and then the inverting unit 420 outputs a low-level switch control signal according to the startup signal to turn off the switch tube Q1. At this time, the static current in the load detection circuit 20 is 0, and the output of the detection signal has been completed.

[0042] The startup power supply VIN may be a power supply for starting the detected load RT or other working power supply that is powered on synchronously with the driving power supply. This embodiment does not require a dedicated power supply to detect whether the load RT is connected to the driving power supply, and does not require additional control chips or other devices to separately control the shutdown of the current control module 300. After the detection is completed and the detection signal is output, the current control module 300 can be automatically shut down immediately, so that the power consumption of the load detection circuit 20 is reduced to 0.

[0043] In this embodiment, the detection control module 400 further includes a delay resistor R3 and a delay capacitor C1, the delay resistor R3 is connected in series between the input end of the second amplifying and shaping unit 410 and the startup power supply VIN, the first end of the delay capacitor C1 is connected to the input end of the second amplifying and shaping unit 410, and the second end of the delay capacitor C1 is connected to the ground. The delay resistor R3 is used to reduce the current output by the startup power supply VIN to protect the load detection circuit 20, and the delay resistor R3 and the delay capacitor C1 are also used to delay the electrical signal output by the startup power supply VIN.

[0044] It should be noted that if the driving power supply connected to the load RT and the starting power supply VIN are powered on at the same time, the first input end of the trigger U6 cannot receive the sampling level in the first time because the load detection circuit 20 is provided with a first current limiting resistor R1, a second current limiting resistor R2 and a first amplifying and shaping unit 210. The electrical signal output by the starting power supply VIN can be further delayed by the delay resistor R3 and the delay capacitor C1, so that the starting signal output by the second amplifying and shaping unit 410 reaches the trigger U6 later than the sampling level, which can ensure that the trigger U6 can output an accurate detection signal.

[0045] like Figure 3 As shown, in another embodiment, the detection control module 400 includes a control unit U7, which is connected to the output module 200 and the current control module 300 respectively to output a start signal and a switch control signal respectively. The control unit U7 can be a single chip microcomputer or a microprocessor.

[0046] Figure 4 The principle block diagram of the lighting device provided by the second embodiment of the present application is shown. For the convenience of description, only the part related to the present embodiment is shown, which is described in detail as follows:

[0047] A lighting device includes a lighting module 10 and a load detection circuit 20 as in the above embodiment. The lighting module 10 may be an LED lighting circuit, and the load detection circuit 20 is connected to the lighting module 10 to detect whether the lighting module is successfully connected to a driving power source. The lighting module 10 corresponds to the load RT in the above embodiment.

[0048] The load detection circuit 20 can detect the connection between the lighting device 10 and the driving power supply when the lighting module 10 is ready to start, and feed back the detection signal to the lighting module, so that the lighting module 10 can configure its own working mode according to the detection signal and the preset program.

[0049] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. In the above embodiments, the description of each embodiment has its own emphasis. For the parts that are not described or recorded in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0050] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A load detection circuit, characterized in that: include: A sampling module, wherein an input end of the sampling module is used to be connected to a load, and the sampling module is configured to output a sampling voltage when a driving power source is connected to the load; an output module, wherein the input end of the output module is connected to the output end of the sampling module, and the output module is configured to output a corresponding detection signal according to the sampled voltage at the output end of the sampling module after receiving a start signal; A current control module, the current control module is arranged between the output terminal of the sampling module and the ground terminal, the current control module is used to limit the current output from the sampling module to the ground terminal; the current control module is also configured to be turned on or off according to a switch control signal; The start signal is first transmitted to the output module, and then transmitted to the current control module after the switch control signal of the current control module is turned off, so as to ensure that the output module can output the detection signal before the current control module is turned off; It also includes a detection control module, which is connected to the current control module and the output module respectively, and is configured to output the start signal and output the switch control signal for shutting down the current control module to the current control module according to the start signal; The detection control module includes a starting power supply, a second amplifying and shaping unit and an inverting unit. The starting power supply is connected to the input end of the second amplifying and shaping unit, and the output end of the second amplifying and shaping unit is connected to the output module, so as to output the starting signal to the output module when the starting power supply outputs a voltage; the second amplifying and shaping unit is also connected to the input end of the inverting unit, and the output end of the inverting unit is connected to the current control module, so as to output the switch control signal to the current control module according to the starting signal.

2. The load detection circuit according to claim 1, characterized in that: The sampling module includes a first current limiting resistor, a first end of the first current limiting resistor is used to be connected to a load, a second end of the first current limiting resistor is an output end of the sampling module, and the sampling module is used to generate a corresponding sampling voltage at the second end of the first current limiting resistor when the load is connected to the driving power supply.

3. The load detection circuit according to claim 1, characterized in that: The output module comprises a first amplifying and shaping unit and a trigger, the input end of the first amplifying and shaping unit is connected to the output end of the sampling module, the output end of the first amplifying and shaping unit is connected to the first input end of the trigger, and the second input end of the trigger is used to receive the start signal; The first amplification and shaping unit is configured to generate a corresponding sampling level according to a sampling voltage at the output end of the sampling module, and the trigger is configured to output the sampling level as the detection signal when the second input end of the trigger receives the start signal.

4. The load detection circuit according to claim 3, characterized in that: The first amplifying and shaping unit includes a first inverter and a second inverter, the input end of the first inverter is connected to the output end of the sampling module, the output end of the first inverter is connected to the input end of the second inverter, and the output end of the second inverter is connected to the first input end of the trigger.

5. The load detection circuit according to claim 1, characterized in that: The current control module includes a switch tube and a current limiting unit, the first conduction end of the switch tube is connected to the output end of the sampling module, the second conduction end of the switch tube is connected to the input end of the current limiting unit, the output end of the current limiting unit is connected to the ground end, the controlled end of the switch tube is used to receive the switch control signal, the switch tube is configured to be turned on or off according to the switch control signal, and the current limiting unit is used to limit the current transmitted from the current control module to the ground end.

6. The load detection circuit according to claim 5, characterized in that: The current limiting unit includes a current limiting tube, a first conduction terminal of the current limiting tube is connected to the second conduction terminal of the switch tube, and a second conduction terminal of the current limiting tube is connected to the ground terminal. The current limiting tube remains turned off so as to allow only a micro current to pass through the current limiting tube.

7. The load detection circuit according to claim 1, characterized in that: The detection control module includes a control unit, and the control unit is connected to the output module and the current control module respectively, so as to output the start signal and the switch control signal respectively.

8. A lighting device, characterized in that: It comprises a lighting module and a load detection circuit as claimed in any one of claims 1 to 7, wherein the load detection circuit is connected to the lighting module to detect whether the lighting module is successfully connected to the driving power supply.

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