Control circuit capable of automatically adjusting brightness gears

Abstract

The utility model relates to the technical field of brightness adjustment, and discloses a control circuit capable of automatically adjusting brightness gears, the control circuit is high in reliability and stable, the control circuit comprises an MCU control circuit (130) used for outputting PWM signals and enable signals, an LED drive circuit (141) and a current detection circuit (142), the signal feedback end of the LED drive circuit (141) is connected with the output end of the current detection circuit (142), and the output end of the current detection circuit (142) is connected with the output end of the MCU control circuit (130). And the control module is used for receiving the level signal and controlling the working current of the LED module according to the level signal so as to adjust the brightness of the LED module.

Description

Technical Field

[0001] This utility model relates to the field of brightness adjustment technology, and more specifically, to a control circuit that can automatically adjust the brightness level. Background Technology

[0002] Dimming of flashlight LED modules typically employs PWM dimming, which picks up and processes the output pulse width information from the dimmer, generates a corresponding PWM signal to control the output duty cycle of the LED drive current from the LED driver module, thereby changing the output power and adjusting the brightness. However, existing technologies suffer from high quiescent current in the drive circuit and relatively simple protection functions, failing to automatically adjust the LED module brightness based on battery voltage. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a control circuit with high reliability and stability that can automatically adjust the brightness level, which addresses the shortcomings of the existing driving circuits, such as high static current, simple protection function, and inability to automatically adjust the brightness of the LED module based on the battery voltage.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to construct a control circuit that can automatically adjust the brightness level, which has the following features:

[0005] The MCU control circuit, which is configured within the control circuit, is used to output PWM signals and enable signals;

[0006] The LED driver circuit has one signal input terminal connected to the enable terminal of the MCU control circuit to receive an enable signal, which is used to trigger and control the working state of the LED module.

[0007] One output terminal of the LED driving circuit is connected to the detection terminal of the MCU control circuit to obtain the voltage value of the LED module when it is working, and output the PWM signal according to the voltage value.

[0008] A current detection circuit, one end of which is connected to one end of the LED module, is used to obtain the voltage value when the LED module is operating.

[0009] The other end of the current detection circuit is connected to the signal output terminal of the MCU control circuit, which is used to receive the PWM signal, compare the PWM signal with the voltage value, and then output a level signal according to the comparison result.

[0010] The signal feedback terminal of the LED driving circuit is connected to the output terminal of the current detection circuit to receive the level signal and control the operating current of the LED module according to the level signal to adjust the brightness of the LED module.

[0011] In some embodiments, the current detection circuit includes at least a comparator.

[0012] The non-inverting input of the comparator is connected to the negative terminal of the LED module via the eighteenth resistor to obtain the voltage value.

[0013] The inverting input of the comparator is connected to the signal output of the MCU control circuit via a series-connected 23rd and 24th resistor to receive the PWM signal.

[0014] The output of the comparator is connected to the signal feedback terminal of the LED driver circuit through a twentieth resistor and a third diode connected in series, and is used to receive the level signal output after comparing the PWM signal with the voltage value.

[0015] In some embodiments, the LED driving circuit includes at least an LED driver.

[0016] One signal input terminal of the LED driver is coupled to the enable terminal of the MCU control circuit.

[0017] The output terminal of the LED driver is connected to the positive terminal of the LED module through a first inductor.

[0018] The signal feedback terminal of the LED driver is coupled to the output terminal of the comparator and is used to receive the level signal.

[0019] In some implementations, the MCU control circuit includes at least a master controller.

[0020] The enable terminal of the main controller is connected to a signal input terminal of the LED driver.

[0021] The detection terminal of the main controller is connected to one end of the LED module.

[0022] The signal output terminal of the main controller is connected to the inverting terminal of the comparator.

[0023] In some embodiments, a charging and voltage detection circuit is also included, which receives an input power signal to charge the battery assembly.

[0024] The output terminal of the charging and voltage detection circuit is connected to the power input terminal of the LED driving circuit.

[0025] In some embodiments, the charging and voltage detection circuit includes at least a battery manager.

[0026] The input terminal of the battery manager is connected to the output terminal of the USB interface.

[0027] The output terminal of the battery manager is connected to the power input terminal of the LED driver circuit.

[0028] In some implementations, a linear voltage regulator circuit is also included, the input of which is connected to the output of the battery manager to receive the input power signal.

[0029] The output terminal of the linear voltage regulator circuit is connected to the power input terminal of the MCU control circuit.

[0030] In some embodiments, the linear voltage regulator circuit includes at least a first diode, a second diode, and a voltage regulator controller.

[0031] The anode of the first diode is connected to the output terminal of the USB interface.

[0032] The anode of the second diode is connected to the output terminal of the battery manager.

[0033] The cathodes of the first diode and the second diode are respectively connected to the input terminal of the voltage regulator controller.

[0034] The output of the battery manager is coupled to the power input of the MCU control circuit.

[0035] In some implementations, a temperature detection circuit is also included, which is used to acquire the temperature signal of the object to be detected.

[0036] One end of the temperature detection circuit is connected to a signal terminal of the MCU control circuit.

[0037] The feedback terminal of the temperature detection circuit is connected to the temperature detection terminal of the MCU control circuit.

[0038] The control circuit for automatically adjusting brightness levels described in this invention includes an MCU control circuit for outputting PWM signals and enable signals, an LED driver circuit, and a current detection circuit. The signal feedback terminal of the LED driver circuit is connected to the output terminal of the current detection circuit to receive a level signal and control the operating current of the LED module based on the level signal, thereby adjusting the brightness of the LED module. Compared with existing technologies, by matching the level signal output by the current detection circuit to the brightness level in the device, the LED driver circuit can automatically adjust the brightness based on the battery voltage (i.e., the voltage value of the LED module during operation). Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0040] Figure 1 This is a circuit diagram of an embodiment of the charging and voltage detection circuit provided by this utility model;

[0041] Figure 2 This is a circuit diagram of an embodiment of the linear voltage regulator circuit provided by this utility model;

[0042] Figure 3 This is a circuit schematic diagram of an embodiment of the MCU control circuit and temperature detection circuit provided by this utility model;

[0043] Figure 4 This is a circuit diagram of an embodiment of the LED driving circuit and current detection circuit provided by this utility model. Detailed Implementation

[0044] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0045] like Figures 1-4 As shown, in the first embodiment of the control circuit for automatically adjustable brightness levels of this utility model, the control circuit for automatically adjustable brightness levels includes a charging and voltage detection circuit 110, a linear voltage regulator circuit 120, an MCU control circuit 130, an LED driver circuit 141, a current detection circuit 142, and a temperature detection circuit 150.

[0046] The charging and voltage detection circuit 110 is used to receive the power signal input from the power supply terminal (USB interface) to charge the battery assembly (corresponding to BT1) and check the voltage signal input from the power supply terminal, and feed it back to the MCU control circuit 130.

[0047] The linear voltage regulator circuit 120 is used to receive the voltage signal input from the USB interface or battery assembly (corresponding to BT1), and to regulate and filter the input voltage signal to output a 2.8V voltage signal.

[0048] The MCU control circuit 130 has the functions of calculation, signal processing, signal detection (such as temperature / current / voltage), and outputting PWM signals and enable signals according to the above signals. It has thresholds (such as temperature / current / voltage).

[0049] The LED driver circuit 141 is used to control the working state of the LED module, and it controls the brightness of the LED module according to the PWM signal output by the MCU control circuit 130.

[0050] The current detection circuit 142 has the functions of current signal detection, signal comparison, and outputting a level signal (high level / low level) according to the comparison result;

[0051] Temperature detection circuit 150 is used to detect the temperature signal of the object under test (such as a battery pack or LED module).

[0052] During product operation, high temperatures will be generated on the outside of the battery pack (corresponding to BT1) or LED module. When the product temperature or LED module temperature is too high or too low, i.e., exceeding the set shutdown threshold, the MCU control circuit 130 will shut down the PWM signal or enable signal output.

[0053] Specifically, the MCU control circuit 130 is configured within the control circuit, and it is used to output a PWM signal and at least one enable signal.

[0054] Furthermore, a signal input terminal of the LED driver circuit 141 is connected to the enable terminal of the MCU control circuit 130 to receive the enable signal input from the MCU control circuit 130. The input enable signal is used to trigger and control the working state of the LED module.

[0055] One output terminal of the LED driver circuit 141 is connected to the detection terminal of the MCU control circuit 130. The MCU control circuit 130 is used to obtain the voltage value of the LED module when it is controlled to work, and adjust the duty cycle of the output PWM signal according to the voltage value, thereby adjusting the brightness of the LED module.

[0056] One end of the current detection circuit 142 is connected to one end of the LED module to obtain the voltage value of the LED module when it is under controlled operation.

[0057] The other end of the current detection circuit 142 is connected to the signal output terminal of the MCU control circuit 130, and is used to receive the PWM signal input from the MCU control circuit 130.

[0058] The current detection circuit 142 compares the input PWM signal with the voltage value, and then outputs a level signal (high level / low level) based on the comparison result.

[0059] Furthermore, the signal feedback terminal of the LED driver circuit 141 is connected to the output terminal of the current detection circuit 142 to receive the level signal output by the current detection circuit 142, and control the operating current of the LED module according to the input level signal to adjust the brightness of the LED module.

[0060] Using this technical solution, the LED driver circuit can automatically adjust the brightness by matching the level signal output by the current detection circuit with the gear setting in the device. The brightness can also be adjusted according to the battery voltage (i.e., the voltage value of the LED module when it is working).

[0061] In some implementations, such as Figure 4 As shown, in order to improve the reliability of LED module brightness adjustment, a comparator U4 can be set in the current detection circuit 142, which has the function of signal comparison;

[0062] Specifically, the non-inverting input (corresponding to pin 1) of comparator U4 is connected to the negative terminal of the LED module through the eighteenth resistor R18 to obtain the voltage value.

[0063] The inverting input (corresponding to pin 3) of comparator U4 is connected to the signal output of MCU control circuit 130 through series-connected resistors R23 and R24 to receive PWM signals. It compares the input voltage value with the PWM signal (or current threshold).

[0064] When the voltage value is greater than the PWM signal, the comparator U4 outputs a high level.

[0065] When the voltage value is less than the PWM signal, the comparator U4 outputs a low level.

[0066] The output of comparator U4 (corresponding to pin 4) is connected to the signal feedback terminal of LED driver circuit 141 through a series-connected twentieth resistor R20 and third diode D3.

[0067] One end of the twentieth resistor R20 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the signal feedback terminal of the LED driver circuit 141. The level signal output by the comparator U4 is input to the LED driver circuit 141 through the twentieth resistor R20 and the third diode D3.

[0068] In some implementations, such as Figure 4 As shown, the LED driving circuit 141 includes at least an LED driver U3, which has the functions of signal reception, switching and brightness control.

[0069] Specifically, one signal input terminal (corresponding to pin 1) of the LED driver U3 is coupled to the enable terminal of the MCU control circuit 130, and is used to receive the enable signal input from the MCU control circuit 130.

[0070] The output terminals (corresponding to pins 3 and 6) of LED driver U3 are connected to the positive terminal of the LED module through the first inductor L1.

[0071] The signal feedback terminal (pin 8) of LED driver U3 is coupled to the output terminal (pin 4) of comparator U4 to receive level signals.

[0072] In some implementations, such as Figure 4 As shown, the MCU control circuit 130 includes at least a master controller U5, which has the functions of calculation, signal reception / processing, outputting PWM signals and enabling signals;

[0073] Specifically, the enable terminal (pin 11) of the main controller U5 is connected to a signal input terminal (pin 1) of the LED driver U3.

[0074] The detection terminal (corresponding to pin 9) of the main controller U5 is connected to one end of the LED module (corresponding to Current-Det) to acquire the voltage value, compare it with its internal voltage threshold, and then output a PWM signal based on the comparison result.

[0075] The signal output terminal (corresponding to pin 8) of the main controller U5 is connected to the inverting terminal (corresponding to pin 3) of the comparator U4 to output PWM signals;

[0076] When the input enable signal is low, the LED driver U3 is turned off.

[0077] When the input enable signal is high, the LED driver U3 is turned on. The voltage signal input to the battery module (corresponding to BT1) is regulated by the LED driver U3 and then input to the positive terminal of the LED module through the first inductor L1, the eleventh capacitor C11 and the sixth capacitor C6 to control the LED module to light up.

[0078] When the LED module is controlled to light up, the main controller U5 detects the current operating voltage of the LED module and analyzes or identifies the voltage of the current battery module (corresponding to BT1). When the voltage value of the battery module (corresponding to BT1) is lower than the preset value, or

[0079] When the product is in a certain position, the main controller U5 provides a reference voltage value (such as a PWM signal) based on the current data, compares it with the non-inverting input, and then outputs it back to the LED driver U3 to adjust the output voltage, so as to stabilize the output current and thus control the brightness of the LED module.

[0080] In some implementations, such as Figure 1 As shown, to ensure the stability of the control circuit operation, a charging and voltage detection circuit 110 can also be provided. This circuit receives the power signal input from the USB interface to charge the battery assembly (corresponding to BT1).

[0081] The output of the charging and voltage detection circuit 110 is connected to the power input terminal (pin 2) of the LED driver U3 (which belongs to the LED driver circuit 141) to provide it with the working voltage signal.

[0082] In some implementations, such as Figure 1 As shown, the charging and voltage detection circuit 110 includes at least a battery manager U1, which enables charging and discharging control through the main controller U5 and has a voltage stabilizing function.

[0083] Specifically, the input terminal (corresponding to pin 4) of the battery manager U1 is connected to the output terminal of the USB interface. The voltage signal output from the USB interface is processed by the voltage regulator TVS1 and the second capacitor C2 before being input to the battery manager U1.

[0084] The output terminal (pin 1) of the battery manager U1 is connected to the power input terminal (pin 2) of the LED driver U3 (belonging to the LED driver circuit 141) through the first capacitor C1.

[0085] In some implementations, such as Figure 2 As shown, it also includes a linear voltage regulator circuit 120, whose input terminal is connected to the output terminal (corresponding to pin 2) of the battery manager U1, for receiving the input power signal.

[0086] The output of the linear regulator circuit 120 is connected to the power input terminal (pin 5) of the main controller U5 (which belongs to the MCU control circuit 130).

[0087] Furthermore, the linear voltage regulator circuit 120 includes at least a first diode D1, a second diode D2, a voltage regulator controller U2, and a MOSFET.

[0088] The anode of the first diode D1 is connected to the output terminal of the USB interface (corresponding to 5.0V).

[0089] The anode of the second diode D2 is connected to the output terminal (corresponding to BAT+) of the battery manager U1.

[0090] The cathodes of the first diode D1 and the second diode D2 are respectively connected to the input terminal (corresponding to D) of the voltage regulator controller U2, providing it with at least two voltage signals.

[0091] The output terminal (corresponding to S) of the battery manager U1 is connected to the power input terminal (corresponding to pin 5) of the main controller U5 (belonging to the MCU control circuit 130) to provide it with a voltage signal;

[0092] The drain of the MOSFET is connected to the output terminal (S) of the battery manager U1.

[0093] The gate of the MOSFET is connected to a signal terminal (pin 7) of the main controller U5 to receive the control signal output by the main controller U5.

[0094] The source of the MOSFET is connected to the common terminal.

[0095] When the load is incorrectly connected or connected to other power sources in reverse, the reverse connection circuit receives abnormal voltage and current; or

[0096] When the voltage of the battery module (corresponding to BT1) is too high or too low; or

[0097] When the charging current is too high or too low, the main controller U5 outputs a high-level control signal according to the detected signal. When the MOSFET is turned on, the 2.8V voltage signal output by the voltage regulator U2 is pulled to ground, and the main controller U5 stops outputting the enable signal, thereby controlling the battery manager U1 and the LED driver U3 to turn off, disconnecting the battery pack (corresponding to BT1) or the load to ensure the safety of circuit operation.

[0098] In some implementations, such as Figure 3 As shown, it also includes a temperature detection circuit 150, which is used to acquire the temperature signal when the LED module is working.

[0099] One end of the temperature detection circuit 150 is connected to a signal terminal (pin 16) of the main controller U5 (which belongs to the MCU control circuit 130).

[0100] The feedback terminal of the temperature detection circuit 150 is connected to the temperature detection terminal (corresponding to pin 13) of the main controller U5 to receive the temperature signal detected by the temperature detection circuit 150.

[0101] Specifically, the product is equipped with two temperature detection sensors. The first can detect the temperature of the connected battery pack (corresponding to BT1), and the other checks the ambient temperature inside the product. When either NTC temperature sensor detects an abnormal temperature, protection will be activated immediately.

[0102] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A control circuit capable of automatically adjusting brightness levels, characterized in that, have: The MCU control circuit, which is configured within the control circuit, is used to output PWM signals and enable signals; The LED driver circuit has one signal input terminal connected to the enable terminal of the MCU control circuit to receive the enable signal, which is used to trigger and control the working state of the LED module. One output terminal of the LED driving circuit is connected to the detection terminal of the MCU control circuit to obtain the voltage value of the LED module when it is working, and output the PWM signal according to the voltage value. A current detection circuit, one end of which is connected to one end of the LED module, is used to obtain the voltage value when the LED module is operating. The other end of the current detection circuit is connected to the signal output terminal of the MCU control circuit, which is used to receive the PWM signal, compare the PWM signal with the voltage value, and then output a level signal according to the comparison result. The signal feedback terminal of the LED driving circuit is connected to the output terminal of the current detection circuit to receive the level signal and control the operating current of the LED module according to the level signal to adjust the brightness of the LED module.

2. The control circuit for automatically adjusting brightness levels according to claim 1, characterized in that, The current detection circuit includes at least one comparator. The non-inverting input of the comparator is connected to the negative terminal of the LED module via the eighteenth resistor to obtain the voltage value. The inverting input of the comparator is connected to the signal output of the MCU control circuit via a series-connected 23rd and 24th resistor to receive the PWM signal. The output of the comparator is connected to the signal feedback terminal of the LED driver circuit through a twentieth resistor and a third diode connected in series, and is used to receive the level signal output after comparing the PWM signal with the voltage value.

3. The control circuit for automatically adjusting brightness levels according to claim 2, characterized in that, The LED driving circuit includes at least an LED driver. One signal input terminal of the LED driver is coupled to the enable terminal of the MCU control circuit. The output terminal of the LED driver is connected to the positive terminal of the LED module through a first inductor. The signal feedback terminal of the LED driver is coupled to the output terminal of the comparator and is used to receive the level signal.

4. The control circuit for automatically adjusting brightness levels according to claim 3, characterized in that, The MCU control circuit includes at least a main controller. The enable terminal of the main controller is connected to a signal input terminal of the LED driver. The detection terminal of the main controller is connected to one end of the LED module. The signal output terminal of the main controller is connected to the inverting terminal of the comparator.

5. The control circuit for automatically adjusting brightness levels according to any one of claims 1-4, characterized in that, It also includes a charging and voltage detection circuit, which receives an input power signal to charge the battery assembly. The output terminal of the charging and voltage detection circuit is connected to the power input terminal of the LED driving circuit.

6. The control circuit for automatically adjusting brightness levels according to claim 5, characterized in that, The charging and voltage detection circuit includes at least a battery manager. The input terminal of the battery manager is connected to the output terminal of the USB interface. The output terminal of the battery manager is connected to the power input terminal of the LED driver circuit.

7. The control circuit for automatically adjusting brightness levels according to claim 6, characterized in that, It also includes a linear voltage regulator circuit, the input of which is connected to the output of the battery manager to receive the input power signal. The output terminal of the linear voltage regulator circuit is connected to the power input terminal of the MCU control circuit.

8. The control circuit for automatically adjusting brightness levels according to claim 7, characterized in that, The linear voltage regulator circuit includes at least a first diode, a second diode, and a voltage regulator controller. The anode of the first diode is connected to the output terminal of the USB interface. The anode of the second diode is connected to the output terminal of the battery manager. The cathodes of the first diode and the second diode are respectively connected to the input terminal of the voltage regulator controller. The output of the battery manager is coupled to the power input of the MCU control circuit.

9. The control circuit for automatically adjusting brightness levels according to claim 8, characterized in that, It also includes a temperature detection circuit, which is used to acquire the temperature signal of the object to be detected. One end of the temperature detection circuit is connected to a signal terminal of the MCU control circuit. The feedback terminal of the temperature detection circuit is connected to the temperature detection terminal of the MCU control circuit.

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