Control circuit for telescopic camp lamp

Abstract

The utility model relates to the technical field of camp lamp control circuits, in particular to a control circuit for a telescopic camp lamp, which comprises an MCU (Microprogrammed Control Unit) and Hall control circuit, a switch potentiometer control circuit, a boost drive circuit, a constant-current dimming control circuit and a double-line double-light-source mode switching control circuit. According to the utility model, a double-light-source three-wire power supply mode of a power supply line of the double light sources is designed into a double-wire power supply double-light-source mode, dimming and color modulation control and mode switching of the double light sources can be smoothly completed, meanwhile, the driving voltage is increased through boosting, and the driving current can be reduced, so that the overall efficiency of the product is improved, and the production cost is reduced. The problem that the voltage of the light source end is low due to the fact that a circuit is too long is solved, the product cost is reduced, and the overall reliability of the product is improved.

Description

Technical Field

[0001] This utility model relates to the field of camping light control circuit technology, and in particular to a control circuit for a telescopic camping light. Background Technology

[0002] The camping light is a retro-style portable lighting tool suitable for camping, patio parties, and creating a homey atmosphere. It features a dual-light source design and an innovative telescopic design. The base and lighting unit of the telescopic camping light are connected via a telescopic pole, which can be extended by approximately 183±5mm, reaching a height of 406±5mm after extension. This provides a wider lighting range, addressing the pain point of limited illumination in traditional camping lights. The telescopic pole light utilizes a telescopic design to increase the lighting range. Because the battery, driver, and light source are separate during extension, the light source needs to extend to 406mm. The dual-light source design, unlike current market solutions where two light sources require four-wire power for independent dimming and at least three-wire power for common anode or common cathode drivers, necessitates the use of a spring wire for extension. A spring wire extending to 406mm would be over 1 meter long. Due to the limited internal space of the telescopic pole, the spring wire diameter must be relatively thin (for three-wire springs combined, the diameter must be thin due to space constraints). An excessively long and thin wire leads to significant voltage drop, resulting in low voltage at the light source, dim lighting, and overall lower efficiency. Utility Model Content

[0003] The main purpose of this utility model is to provide a control circuit for a retractable camping light, including an MCU and Hall control circuit, a switch potentiometer control circuit, a boost drive circuit, a constant current dimming control circuit, and a dual-line dual-light source mode switching control circuit.

[0004] Preferably, the MCU and Hall control circuit includes a Hall switch U6, a microcontroller U2, an LDO regulator U5, resistors R12 and R13, and two LEDs connected in series to pins P2-1 and P2-2 of the microcontroller U2. A capacitor C31 is connected between the VDD and VSS pins of the microcontroller U2. A resistor R28 is connected to pin P0-1 of the microcontroller U2. A switch SW is connected to pin P0-0 of the microcontroller U2. A resistor R15 and capacitor C32 are connected to pin P1-6 of the microcontroller U2. A resistor R14 is connected to pin P1-5 of the microcontroller U2. Connect capacitor C42 to the pins. Connect pin 3 of Hall switch U6 to pin P2-3 of microcontroller U2. Connect resistor R30 between pins 2 and 3 of Hall switch U6. Connect capacitors C26 and C34 in series between pins 2 and 3 of Hall switch U6. Connect pin 1 of Hall switch U6 to ground. Connect pin 2 of LDO regulator U5 to the PWM pin of microcontroller U2. Connect capacitors C30 and C33 and resistor R10 in parallel between pins 1 and 2 of LDO regulator U5. Connect capacitors C36 and C37 in parallel between pins 1 and 3 of LDO regulator U5.

[0005] Preferably, the switch potentiometer control circuit includes a switch potentiometer SR1, which includes a switch S1 and a potentiometer RP connected in series. One end of the potentiometer RP is connected to a resistor R40, and the other end is grounded. One end of the switch S1 is connected to a resistor R29. The switch potentiometer SR1 is connected to the microcontroller U2 through a T3V network.

[0006] Preferably, the boost drive circuit includes a boost control chip U4, capacitors C12, C8, and C7 connected in parallel and then connected to a series circuit of resistor R25, capacitor C45, resistor R20, and resistor R23, and connected between pins 1 and 4 of the boost control chip U4, resistors R26, R31, and capacitor C38 connected in series and then connected to pin 7 of the boost control chip U4, with the other end grounded, inductor L2 and capacitor C13 connected in series and then connected to pin 10 of the boost control chip U4, capacitors C39, C40, and C41 connected in parallel and then connected to pin 11 of the boost control chip U4, capacitor C43 connected to pin 8 of the boost control chip U4, resistor R24 ​​connected to pin 6 of the boost control chip U4, and the boost control chip U4 and the microcontroller U2 are connected through the EN1 network.

[0007] Preferably, the constant current dimming control circuit includes an operational amplifier U3. Pin 1 of the operational amplifier U3 is connected to a resistor R38. A capacitor C15 is connected between pins 2 and 5 of the operational amplifier U3. Resistors R38 and R39 are connected in series and then connected to pin 3 of the operational amplifier U3. Resistors R37, capacitors C14 and C35 are connected in parallel and then connected between pins 2 and 3 of the operational amplifier U3. Pin 4 of the operational amplifier U3 is connected to a capacitor C18. The operational amplifier U3 and the microcontroller U2 are connected through a T3V network.

[0008] Preferably, the dual-line dual-light source mode switching control circuit includes N-channel MOSFETs Q2, Q4, Q7, Q8, Q18, and Q19. Warm light module LED2 and white light module LED3 are connected in parallel and then connected between P-channel MOSFETs Q7 and Q8. Resistor R16 is connected between pins 2 and 3 of P-channel MOSFET Q7. Pin 2 is connected to NPN transistor Q18. Resistor R16 is connected between pins 2 and 3 of P-channel MOSFET Q8. Pin 2 of P-channel MOSFET Q8 is connected to NPN transistor Q19. Resistor R18 is connected between the two pins of N-channel MOSFET Q2, and the other pin is connected to pin 1 of P-channel MOSFET Q8. Resistor R19 is connected between the two pins of N-channel MOSFET Q4, and the other pin is connected to pin 1 of P-channel MOSFET Q7.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] This invention transforms the power supply line of a dual-light source system from a three-wire dual-light source mode to a dual-wire dual-light source mode, enabling smooth dimming and color adjustment control and mode switching for both light sources. Simultaneously, by boosting the voltage to increase the driving voltage, the driving current can be reduced (P=UI; with a fixed power, a higher boost voltage allows for a smaller current, thus reducing line loss even with thin and long lines due to space constraints). This improves the overall efficiency of the product, solves the problem of low voltage at the light source end due to excessively long lines (dual-wire power supply has fewer wires than three-wire power supply; in situations with limited space in telescopic tubes, the wire diameter for dual-wire power supply control can be larger, resulting in significantly lower line loss and voltage drop, and higher overall efficiency), reduces product cost (dual-wire power supply has fewer wires than three-wire power supply, making spring wires easier to manufacture), and enhances the overall reliability of the product. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the MCU and Hall control circuit of this utility model;

[0012] Figure 2This is a schematic diagram of the switch potentiometer control circuit of this utility model;

[0013] Figure 3 This is a schematic diagram of the boost drive circuit of this utility model;

[0014] Figure 4 This is a schematic diagram of the constant current dimming control circuit of this utility model;

[0015] Figure 5 This is a schematic diagram of the dual-line dual-light source mode switching control circuit of this utility model. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0017] Please see Figure 1 This embodiment provides a control circuit for a retractable camping light, including an MCU and Hall effect control circuit, a switch potentiometer control circuit, a boost drive circuit, a constant current dimming control circuit, and a dual-line dual-light source mode switching control circuit.

[0018] Preferably, the MCU and Hall control circuit includes a Hall switch U6, a microcontroller U2, an LDO regulator U5, resistors R12 and R13, and two LEDs connected in series to pins P2-1 and P2-2 of the microcontroller U2. A capacitor C31 is connected between the VDD and VSS pins of the microcontroller U2. A resistor R28 is connected to pin P0-1 of the microcontroller U2. A switch SW is connected to pin P0-0 of the microcontroller U2. A resistor R15 and capacitor C32 are connected to pin P1-6 of the microcontroller U2. A resistor R14 is connected to pin P1-5 of the microcontroller U2. Connect capacitor C42 to the pins. Connect pin 3 of Hall switch U6 to pin P2-3 of microcontroller U2. Connect resistor R30 between pins 2 and 3 of Hall switch U6. Connect capacitors C26 and C34 in series between pins 2 and 3 of Hall switch U6. Connect pin 1 of Hall switch U6 to ground. Connect pin 2 of LDO regulator U5 to the PWM pin of microcontroller U2. Connect capacitors C30 and C33 and resistor R10 in parallel between pins 1 and 2 of LDO regulator U5. Connect capacitors C36 and C37 in parallel between pins 1 and 3 of LDO regulator U5.

[0019] Preferably, the switch potentiometer control circuit includes a switch potentiometer SR1, which includes a switch S1 and a potentiometer RP connected in series. One end of the potentiometer RP is connected to a resistor R40, and the other end is grounded. One end of the switch S1 is connected to a resistor R29. The switch potentiometer SR1 is connected to the microcontroller U2 through a T3V network.

[0020] Preferably, the boost drive circuit includes a boost control chip U4, capacitors C12, C8, and C7 connected in parallel and then connected to a series circuit of resistor R25, capacitor C45, resistor R20, and resistor R23, and connected between pins 1 and 4 of the boost control chip U4, resistors R26, R31, and capacitor C38 connected in series and then connected to pin 7 of the boost control chip U4, with the other end grounded, inductor L2 and capacitor C13 connected in series and then connected to pin 10 of the boost control chip U4, capacitors C39, C40, and C41 connected in parallel and then connected to pin 11 of the boost control chip U4, capacitor C43 connected to pin 8 of the boost control chip U4, resistor R24 ​​connected to pin 6 of the boost control chip U4, and the boost control chip U4 and the microcontroller U2 are connected through the EN1 network.

[0021] Preferably, the constant current dimming control circuit includes an operational amplifier U3. Pin 1 of the operational amplifier U3 is connected to a resistor R38. A capacitor C15 is connected between pins 2 and 5 of the operational amplifier U3. Resistors R38 and R39 are connected in series and then connected to pin 3 of the operational amplifier U3. Resistors R37, capacitors C14 and C35 are connected in parallel and then connected between pins 2 and 3 of the operational amplifier U3. Pin 4 of the operational amplifier U3 is connected to a capacitor C18. The operational amplifier U3 and the microcontroller U2 are connected through a T3V network.

[0022] Preferably, the dual-line dual-light source mode switching control circuit includes N-channel MOSFETs Q2, Q4, Q7, Q8, Q18, and Q19. Warm light module LED2 and white light module LED3 are connected in parallel and then connected between P-channel MOSFETs Q7 and Q8. Resistor R16 is connected between pins 2 and 3 of P-channel MOSFET Q7. Pin 2 is connected to NPN transistor Q18. Resistor R16 is connected between pins 2 and 3 of P-channel MOSFET Q8. Pin 2 of P-channel MOSFET Q8 is connected to NPN transistor Q19. Resistor R18 is connected between the two pins of N-channel MOSFET Q2, and the other pin is connected to pin 1 of P-channel MOSFET Q8. Resistor R19 is connected between the two pins of N-channel MOSFET Q4, and the other pin is connected to pin 1 of P-channel MOSFET Q7.

[0023] In the above circuit, BAT+ is the positive battery network, LED+ is the positive output network of the boost driver (connected to the light source module to power the light source), LED- is the negative network connected to the light source (powering the light source), MODE is the Hall switch signal output network (detecting the light source mode), T3V is the MCU powering the U3 operational amplifier and SR1 switch potentiometer, EN-C is the white light mode control signal, EN-W is the warm light mode control signal, SW is the SR1 switch signal detection network, RP is the SR1 potentiometer dimming signal detection network, and EN1 is the enable signal control for the boost chip.

[0024] Power-on control principle: When the user rotates the potentiometer SR1 to power on, the switch SR1 is turned on, and the voltage at pin SW is pulled to ground. When microcontroller U2 detects that the voltage at pin 1 of the SW network has been pulled from high level to ground (power-on signal), pin 2 of microcontroller U2 will output a high level through the T3V network to power operational amplifier U3 and the resistor of potentiometer SR1. Simultaneously, the resistance of the potentiometer will gradually increase, and the voltage at pin RP will also gradually increase (dimming signal). The voltage of the network is filtered by R15 and C32 and then sent to pin 19 of microcontroller U2. When microcontroller U2 detects that the voltage at pin 19 is gradually increasing, after receiving the power-on signal and dimming signal from the outside, pin 13 of microcontroller U2 outputs a high-level signal through the EN1 network to control the boost control chip U4 to start working. After the boost control chip U4 receives the high-level signal at pin 13, the internal MOS of the boost control chip U4 will turn on, and the boost chip will start working. At this time, a stable voltage will be boosted across the output capacitor C7 to drive the light source.

[0025] Constant current dimming principle: When the user rotates the potentiometer SR1, the resistance of the potentiometer gradually increases, and the voltage of the RP network also gradually increases (dimening signal). The voltage of the RP network, after being filtered by the RC circuit of R15 and C32, goes to pin 19 of microcontroller U2. When microcontroller U2 detects the gradual increase in voltage at pin 19, it receives the power-on signal and dimming signal from the outside. Upon receiving the power-on signal, microcontroller U2 outputs a high-level signal through the EN1 network to control the boost control chip U4 to work, and outputs a high-level signal through the T3V network to power the operational amplifier U3. Upon receiving the dimming signal, microcontroller U2 controls pin 12 to output a PWM signal. The PWM signal, after being filtered by a two-stage RC divider (R39, C35, R38, R37, C14), reaches the inverting input (pin 3) of operational amplifier U3. Pin 3 serves as the reference voltage. Pin 1 of operational amplifier U3, via current-limiting resistor R21, detects the voltage across current-sensing resistor R36. When the non-inverting input (pin 1) of operational amplifier U3 detects excessive current in the light source circuit (i.e., the voltage at pin 1 is higher than at pin 3), pin 4 of operational amplifier U3 outputs a high level to increase the voltage at pin FB. When boost control chip U4 detects this increased voltage at pin FB, it controls... The PWM duty cycle inside the chip controls the internal MOSFET, thereby lowering the output voltage of the LED+ network. When the LED+ network output voltage is lowered, the current flowing through the current sensing resistor R36 also decreases. Operational amplifier U3's pin 1 detects this lower voltage, and since the voltage detected at the non-inverting input of pin 1 is lower than the voltage at the inverting input of pin 3, pin 4 of operational amplifier U3 outputs a low level to further lower the FB voltage. Boost control chip U4 detects this low voltage at pin 4 and, by controlling the PWM duty cycle inside the chip, controls the internal MOSFET, thereby raising the output voltage of the LED+ network. This means that the current flowing through the current sensing resistor R36 also increases. This cycle repeats, and the negative feedback circuit adjusts the current to be lower when the current is high and to be higher when the current is low, thus keeping the current flowing through the light source constant. The magnitude of the PWM duty cycle follows the change in the switching potentiometer resistor. When pin 19 of the microcontroller U2 detects that the dimming signal has increased, pin 12 of the microcontroller U2 outputs an increased PWM duty cycle to increase the output current at the light source end (increasing the PWM duty cycle can change the reference voltage at pin 3 of the operational amplifier U3, and the principle of adjusting the current is similar to the constant current principle mentioned above). Increasing the output current means increasing the brightness of the light source module, and vice versa. This is similar to increasing the brightness, ultimately achieving dimming of the light source module.

[0026] Principle of warm light and white light mode switching control:

[0027] Warm Light Mode: When the user switches to warm light mode, if Hall switch U6 does not sense an external magnetic field, pin 3 of Hall switch U6 outputs a high level through pull-up resistor R30 to the MODE network. After pin 8 of microcontroller U2 detects the high level in the MODE network, pin 9 of microcontroller U2 outputs a high level, which, through the EN-W network, controls the saturation conduction of NPN transistor Q19 (when the base of NPN transistor Q19 is high, the emitter junction and collector junction are forward biased, resulting in saturation conduction). The conduction of NPN transistor Q19 pulls the base of P-channel MOSFET Q8 low to ground. Q8 is saturated and conducting. Due to the high level of the EN-W network, the N-channel MOSFET Q4 is saturated and conducting. At this time, the boost voltage drives the LED from the LED+ network through the P-channel MOSFET Q8 to the positive terminal of LED2 (warm light), the negative terminal of LED2 (warm light), the drain (D) of N-channel MOSFET Q4, the source (S) of N-channel MOSFET Q4, the LED- network, and the current sensing resistor R36 to ground, forming a loop (at this time, due to the low level of the EN-C network, the P-channel MOSFET Q7 and the N-channel MOSFET Q2 are turned off). The LED2 (warm light) module is forward biased and lit, while the LED3 (white light) module is reverse biased and cut off, and does not light up.

[0028] White Light Mode: When the user switches to white light mode, Hall switch U6 senses an external magnetic field. Pin 3 of Hall switch U6 outputs a low level (MODE network). After pin 8 of microcontroller U2 detects this low level, pin 9 of microcontroller U2 outputs a low level through the EN-W network to turn off P-channel MOSFET Q8 and N-channel MOSFET Q4 (EN-W low level, NPN transistor Q19 is not conducting, P-channel MOSFET Q8's base is high). Pin 11 of microcontroller U2 outputs a high level via the EN-C network to control NPN transistor Q18 to saturate and conduct (NPN transistor Q18's base is high, NPN transistor Q18's emitter junction is positive). When the collector junction is forward biased (transistor saturation conduction), the NPN transistor Q18 conducts, which pulls the base of the P-channel MOSFET Q7 to ground, causing Q7 to saturate and conduct. Since the EN-C network is high, the N-channel MOSFET Q2 saturates and conducts. At this time, the 12V boost voltage from the LED+ network passes through the P-channel MOSFET Q7 to the positive terminal of LED3 white light, the negative terminal of LED3 white light, the drain (D) of N-channel MOSFET Q2, the source (S) of N-channel MOSFET Q2, the LED- network, and the R36 current sensing resistor to ground, forming a loop. The LED3 white light module lights up after being forward biased, while the LED2 warm light module does not light up after being reverse biased.

[0029] Overcurrent and short-circuit protection: After the LED network is filtered by R14 and C42, it reaches pin 18 of microcontroller U2. When pin 18 of microcontroller U2 detects the excessive current threshold in the light source circuit, pins 13, 12, 11, 9 and 2 of microcontroller U2 will output a low level to turn off the output, i.e., turn off the power (the power-off principle is the opposite of the power-on principle, which will not be described in detail here), thereby protecting the components in the circuit from being burned out due to abnormal conditions such as output short circuit and overcurrent.

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A control circuit for a retractable camping light, characterized in that, Includes MCU and Hall control circuit, switch potentiometer control circuit, boost drive circuit, constant current dimming control circuit and dual-line dual-light source mode switching control circuit; The MCU and Hall effect control circuit includes a Hall switch U6, a microcontroller U2, an LDO regulator U5, resistors R12 and R13, and two LEDs connected in series to pins P2-1 and P2-2 of microcontroller U2. A capacitor C31 is connected between the VDD and VSS pins of microcontroller U2. A resistor R28 is connected to pin P0-1 of microcontroller U2. A switch SW is connected to pin P0-0 of microcontroller U2. Resistors R15 and capacitor C32 are connected to pins P1-6 of microcontroller U2. A resistor R14 is connected to pin P1-5 of microcontroller U2. Connect capacitor C42. Connect pin 3 of Hall switch U6 to pin P2-3 of microcontroller U2. Connect resistor R30 between pins 2 and 3 of Hall switch U6. Connect capacitors C26 and C34 in series between pins 2 and 3 of Hall switch U6. Connect pin 1 of Hall switch U6 to ground. Connect pin 2 of LDO regulator U5 to PWM pin of microcontroller U2. Connect capacitors C30 and C33 and resistor R10 in parallel between pins 1 and 2 of LDO regulator U5. Connect capacitors C36 and C37 in parallel between pins 1 and 3 of LDO regulator U5. The switch potentiometer control circuit includes a switch potentiometer SR1, which includes a switch S1 and a potentiometer RP connected in series. One end of the potentiometer RP is connected to a resistor R40 and the other end is grounded. One end of the switch S1 is connected to a resistor R29. The switch potentiometer SR1 is connected to the microcontroller U2 through the T3V network. The boost drive circuit includes a boost control chip U4. Capacitors C12, C8, and C7 are connected in parallel and then connected to a series circuit of resistors R25, C45, R20, and R23, and connected between pins 1 and 4 of the boost control chip U4. Resistors R26, R31, and capacitor C38 are connected in series and then connected to pin 7 of the boost control chip U4, with the other end grounded. Inductor L2 and capacitor C13 are connected in series and then connected to pin 10 of the boost control chip U4. Capacitors C39, C40, and C41 are connected in parallel and then connected to pin 11 of the boost control chip U4. Capacitor C43 is connected to pin 8 of the boost control chip U4. Resistor R24 ​​is connected to pin 6 of the boost control chip U4. The boost control chip U4 and the microcontroller U2 are connected through the EN1 network. The constant current dimming control circuit includes an operational amplifier U3. Pin 1 of the operational amplifier U3 is connected to a resistor R38. A capacitor C15 is connected between pins 2 and 5 of the operational amplifier U3. Resistors R38 and R39 are connected in series and then connected to pin 3 of the operational amplifier U3. Resistors R37, capacitors C14 and C35 are connected in parallel and then connected between pins 2 and 3 of the operational amplifier U3. Pin 4 of the operational amplifier U3 is connected to a capacitor C18. The operational amplifier U3 and the microcontroller U2 are connected through a T3V network. The dual-line dual-light source mode switching control circuit includes N-channel MOSFETs Q2 and Q4, P-channel MOSFETs Q7 and Q8, NPN transistors Q18 and Q19. Warm light module LED2 and white light module LED3 are connected in parallel between P-channel MOSFETs Q7 and Q8. Resistor R16 is connected between pins 2 and 3 of P-channel MOSFET Q7. Connect the NPN transistor Q18 to the NPN transistor Q19. Connect the two pins of the N-channel MOSFET Q2 to the NPN transistor Q19. Connect the other pin to the pin 1 of the P-channel MOSFET Q8. Connect the two pins of the N-channel MOSFET Q2 to the NPN transistor Q19. Connect the other pin to the pin 1 of the P-channel MOSFET Q7. Connect the two pins of the N-channel MOSFET Q4 to the NPN transistor Q19. Connect the other pin to the pin 1 of the P-channel MOSFET Q7.

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