A breeding lamp control circuit for simulating natural light

Abstract

The present invention discloses a breeding lamp control circuit for simulating natural light, which includes: DIM+ and DIM- are external dimming control terminals for inputting control signals; the control signals are input to U1, and U1 outputs PWM; U1 has 8 pins, and the 6th and 7th pins of U1 output positive and negative PWM, driving the photocoupler to achieve isolation conversion. When the PWM duty cycle of the 6th pin of U7B decreases, the duty cycle of the 7th pin increases. At this time, after integration by the integration circuit and then through the filter circuit, the signal converted from PWM is changed into a stable analog signal; thus, it is amplified by Q2, isolated by D6, and R6 adds the signal that changes according to PWM to the voltage reference of the main power supply. The present invention first adjusts the current, and automatically switches to adjusting the voltage when the current is lower than 30%. When the driving current of the LED is adjusted to a very low level, the light remains stable, and even a very weak brightness will not flicker.

Description

Technical Field

[0001] The present invention belongs to the technical field of breeding lamp control circuits, and particularly relates to a breeding lamp control circuit that simulates natural light. Background Art

[0002] Due to the development of the market economy, the global aquaculture industry has grown rapidly. According to network data statistics, the export of breeding lamps in Guangdong Province reached more than 40 billion yuan, and breeding lamps once became a highly competitive area in the LED lamp industry. Since the illuminance of breeding lamps is to shorten the growth period of animals and also to enable animals to better adapt to the growth environment as much as possible, lamp manufacturers will adopt different spectra and more advanced controllers. The working condition of LED lamps is that a constant working current is required to ensure that the semiconductor LED lamps will not be burned out. Therefore, in the application process, we will give a precise constant current to the LED lamp beads. For example, Patent Application No. 201720260884.3 discloses an LED poultry breeding lighting control system.

[0003] The drive controller usually adopts a constant voltage and constant current working mode. However, when the LED lamp is adjusted to a very low current, the LED lamp is prone to flickering. The main reason is that the current sampling resistor cannot be too large. If it is too large, the drive power supply will reduce efficiency and increase unreliability. If the resistance is reduced, the loss will be reduced, but when the current sampling resistor is too small, it will increase the difficulty of circuit recognition, resulting in unstable current of the LED lamp and the phenomenon of lamp flickering. Summary of the Invention

[0004] Based on this, the primary object of the present invention is to provide a breeding lamp control circuit that simulates natural light. When the light dims: the circuit first adjusts the current, and when the current is reduced to 30%, it automatically switches to the voltage reduction mode. At this time, the constant current circuit stabilizes at 30% of the current, and the voltage is reduced to achieve the process of 30% - 0% of the lamp; when the light changes from off to on, the voltage of the power supply is first increased, and when the brightness of the LED lamp beads reaches 30%, it switches to the current adjustment mode. In this way, the balance of light and the linearity of brightness are achieved.

[0005] Another object of the present invention is to provide a breeding lamp control circuit that simulates natural light, which realizes a very dim light of the LED lamp and a lighting effect with a minimum current of 1 mA or lower.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A breeding lamp control circuit that simulates natural light, characterized by including the following:

[0008] DIM+ and DIM- are external dimming control terminals for inputting control signals; the control signals are input to U1, and U1 outputs PWM.

[0009] U1 has 8 pins. Pins 6 and 7 of U1 are connected to the outputs of the forward and reverse PWM, driving the optocoupler to achieve the isolation conversion function. U1 is connected to U2 and U3. U2 and U3 form a push-pull drive, mainly to achieve the stability of PWM when the ambient temperature changes. The 5V voltage is input into the integration circuit in the form of PWM to achieve the function of digital-to-analog conversion.

[0010] The PWM is divided into three paths: the first path is filtered into a DC voltage by the integration circuit and then enters the positive terminal of the comparator of U4. After current amplification, the output is applied to the constant current control circuit of the main power supply to achieve the change of current and the change of the brightness of the LED lamp. The second path of the PWM signal also passes through the integration circuit and is applied to U6A to achieve the switching circuit of current adjustment and voltage adjustment. The third path of the PWM is applied to U7B to achieve the inversion of the duty cycle of the PWM and is output after being inverted by U7B. The positive terminal of U6A is used as a reference for the switching circuit. D4 and R7 form a window comparator and are connected to the positive terminal of U6A. When the output terminal is at a high level of 12V, 12V is fed back to the positive terminal of U6A through D4 and R7, making the voltage at the positive terminal of U6A higher. U6A is connected to U7B. The 6th pin of U7B is the negative terminal, connected to the PWM. The 5th pin is the positive terminal, connected to the voltage division circuit. The 7th pin is the output terminal, connected to the integration circuit. When the output terminal of U6A is high, it is divided by the voltage division circuit to obtain a voltage of about 2V. After being filtered by C17, it is input to the 5th pin of U7B. At this time, the PWM at the 6th pin of U7B is compared with 2V, and the 7th pin follows the inverted PWM of the 6th pin. When the duty cycle of the PWM at the 6th pin of U7B decreases, the duty cycle of the 7th pin increases. At this time, it is integrated by the integration circuit and then filtered by the filter circuit to convert the signal converted from the PWM into a stable analog signal. After the filter circuit, there are Q2 and D6. Q2 and D6 are connected in parallel with C20 and then connected to R6, and output through R6. In this way, Q2 amplifies, D6 isolates, and R6 adds the signal that changes according to the PWM to the voltage reference of the main power supply. The main function of C20 is to quickly add this signal to the output terminal when starting up, so that the reference of the output terminal accelerates to be stable and there will be no phenomenon of lamp flashing.

[0011] Furthermore, there are D1 and R1 connected between DIM+ and U1. Among them, D1 is used to prevent U1 from being burned out when there is high voltage from the outside, and R1 acts as a buffer. There is R3 set between DIM+ and DIM-. R3 is used for discharging to quickly discharge the voltage of pin 3 when the power is off.

[0012] Furthermore, the variable resistor, 0-10V dimmable light, and PWM can all be used as control signals and are input through DIM+ and DIM-.

[0013] Furthermore, the integration circuit composed of R12, C3, R9, and C4, where R12 is connected after U2 and U3, C3 is grounded, R9 is connected to R12, and C4 is grounded.

[0014] Further, the 4th pin of U4 outputs, and D2 and D3 are connected between the output terminal of U4 and the grounded terminal 3rd pin, which is used as the reference for the lowest output voltage control signal, retaining 10% of the current, so that the main power supply will not have no energy due to shutdown, resulting in the phenomenon of lamp flashing; at the same time, D2 and D3 are fed back to the negative terminal of U4. Since the VF values of the two diodes are 0.6V, the two in series are 1.2V, that is, the output terminal of the 4th pin of U4 is always 1.2V higher than the input terminal, thereby realizing that the current reference will not be reduced to 0V. To achieve retaining 10% of the lowest current, VR-A is used to control the constant current circuit reference pin of the main power supply at the output terminal of the circuit of the present invention, realizing the function of current dimming.

[0015] Further, R22 is connected in series to the 3rd pin of U4. R22 is mainly used for the holding current of D2 and D3. The output from the 3rd pin of U4 to the ground is in reverse phase. The feedback signal passing through D2 and D3 has no current, resulting in a very low conduction voltage. D2, D3, and R22 form a loop, so as to ensure that the voltage fed back to the 3rd pin of U4 is lower than 1.2V at the output terminal. Due to the virtual short function of U4, the output terminal 4th pin = 1st pin = 3rd pin + D2 + D3; thus, it is 1.2V higher than the input terminal.

[0016] Further, R5, R13, and RT1 are connected to the 4th pin of U4, forming a voltage dividing circuit. At the same time, C5 is also connected to the 4th pin of U4. C5 filters and outputs to the control reference of the constant current power supply, realizing the function of dimming and constant current.

[0017] Further, Q4, C8, R14, U5, R15, R16, and C9 form a 5V voltage stabilizing circuit, and the 5V voltage stabilizing circuit supplies power to U4; Q1, R26, ZD1, C15, and C16 form a 12V voltage stabilizing circuit, and the 12V voltage stabilizing circuit supplies power to U6.

[0018] Further, D5, R21, R11, RC12, and R23 form an integrating circuit, converting the PWM signal into a variable analog signal. R17 and C13 form a filtering circuit to stabilize the voltage input to the negative terminal of U6A. The function of D5 is isolation, preventing the integrating circuit from affecting the PWM function.

[0019] Further, the 5th pin of U7B is connected to the voltage dividing circuit R10 and R20, and the 7th pin is connected to the integrating circuit R18 and C18. When the output terminal of U6A is high, it is voltage-divided by R10 and R20, and the integrating circuit is connected to the filtering circuit, where the filtering circuit is composed of R27, R19, C19, and R29.

[0020] The usual dimming method is to lower the current and add a high-power resistor at the output end for current sampling. However, this method can only maintain the minimum current above 5%. If it is lower, there is no way to stabilize the current, and the LED lamp will flicker. The present invention mainly adjusts the current first and then the voltage. When the current is adjusted to about 30%, it switches to voltage adjustment. When the output voltage drops to the VF value of the LED, the driving current of the LED becomes very low, and even a current below 1 mA can be achieved, and the current is very stable.

[0021] Moreover, since the output voltage must be very stable when the current is maintained at 30%, the LED lamp can be completely turned off when the output voltage is lower than the VF value of the LED. The same is true when it is lit. First, it rises from below the lamp voltage of the LED until the current reaches 30%, and then it switches to the constant current mode. In this way, the brightness of the lamp is turned on very gently, making it very comfortable for the farmed animals to adapt. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the circuit diagram of the dimming control part implemented by the present invention.

[0023] Figure 2 It is the circuit diagram of the analog-to-digital conversion implemented by the present invention to output a unified PWM signal to drive the photocoupler.

[0024] Figure 3 It is the reference circuit diagram of the digital-to-analog conversion of the PWM signal after isolation and finally current amplification to control the constant current power supply implemented by the present invention.

[0025] Figure 4 It is the circuit diagram of the 5V voltage reference implemented by the present invention.

[0026] Figure 5 It is the circuit diagram of the regulated power supply for the U1 controller implemented by the present invention.

[0027] Figure 6 It is the circuit diagram of the switching circuit between current dimming and voltage dimming and the voltage dimming circuit implemented by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Figure 1 As shown, it is the aquaculture lamp control circuit that simulates natural light implemented by the present invention.

[0030] Main function description: The input control signals, namely variable resistor, 0 - 10V, and PWM signals, are converted into a fixed PWM signal. Then, through opto - isolation (isolation enables a single controller to control multiple power supplies without interference), it is converted into a PWM signal, integrated into a stable linearly variable voltage to control the current reference of the main power supply, achieving the function of adjustable current. When the PWM duty cycle is lower than 30%, it is converted to voltage reference control, enabling both the output voltage and current of the main power supply to be controlled, achieving the LED lamp

[0031] Among them, according to the schematic diagram, the circuit successively includes: a power supply part; a reference voltage part; an AD conversion part; an isolation and DA conversion part; a function switching part; an AD conversion and current amplification part; and finally, it can drive any secondary constant - current power supply.

[0032] Specifically, combined with Figure 2 As shown, DIM + and DIM - are external dimming control terminals. A variable resistor, a 0 - 10V dimmer, and PWM can all be used as control signals. D1 is used to prevent U1 from being burned out when there is high voltage externally. R1 acts as a buffer, and R3 is used for discharging, quickly discharging the voltage at pin 3 when the power is off.

[0033] The 6th and 7th pins of U1 output positive and negative PWM, driving the opto - isolator to achieve the isolation conversion function through the opto - isolator. U2 and U3 form a push - pull drive, inputting the 5V voltage in the form of PWM into the integration circuit composed of R12, C3, R9, C4, etc., to achieve the function of digital - to - analog conversion. After filtering into a DC voltage, it enters the positive terminal of the comparator of U4 for current amplification. The 4th pin of U4 outputs. D2 and D3 are used as the reference for the lowest output voltage control signal, retaining 10% of the current, so that the main power supply will not have no energy due to being turned off, resulting in the phenomenon of lamp flashing. D2 and D3 are fed back to the negative terminal of U4. Since the VF values of the two diodes are 0.6V, the two in series are 1.2V, that is, the output terminal of the 4th pin of U4 is always 1.2V higher than the input terminal, thereby ensuring that the current reference will not be reduced to 0V, achieving the retention of 30% of the lowest current. The R22 connected in series at the 3rd pin of U4 is mainly used to maintain the current of D2 and D3. The output from the 3rd pin of U4 to the ground is in - phase inversion. The feedback signal through D2 and D3 has no current, resulting in a very low conduction voltage. D2, D3, and R22 form a loop, ensuring that the voltage fed back to the 3rd pin of U4 is lower than 1.2V at the output terminal. Due to the virtual - short function of U4, the output terminal 4th pin = 1st pin = 3rd pin + D2 + D3; achieving a voltage 1.2V higher than the input terminal. Among them, R5, R13, and RT1 form a voltage division, and C5 filters and outputs to the control reference of the constant - current power supply to achieve the function of dimming constant - current, as Figure 3 shown.

[0034] Figure 4As shown, Q4, C8, R14, U5, R15, R16, and C9 form a 5V voltage stabilization circuit, and the 5V voltage stabilization circuit supplies power to U4. Figure 5 As shown, Q1, R26, ZD1, C15, and C16 form a 12V voltage stabilization circuit, and the 12V voltage stabilization circuit supplies power to U6.

[0035] Moreover, Q4, C8, U5, R15, R16, and C9 serve as a 5V voltage stabilization reference circuit.

[0036] Figure 6 As shown, D5, R21, R11, RC12, and R23 form an integration circuit to convert the PWM signal into a variable analog signal. R17 and C13 form a filtering circuit to stabilize the voltage at the negative terminal of U6. The function of D5 is isolation, preventing the integration circuit from affecting the PWM function. The positive terminal of U6A serves as a reference, mainly for switching the circuit. That is, when the duty cycle of the PWM is less than 30%, the output terminal of U6A is at a high level. D4 and R7 form a window comparator. When the output terminal is at a high level, it is 12V, and 12V is fed back to the positive terminal of U6 through D4 and R7, making the voltage at the positive terminal of U6 higher. In this way, when the circuit switches, it does not repeatedly switch at the edge of the reference point. D4 is used for isolation, so that when the voltage at the output terminal is low, it will not be interfered by the voltage at the positive terminal.

[0037] U6A is connected to U7B. The 6th pin of U7B is the negative terminal, connected to the PWM. The 5th pin is the positive terminal, connected to the voltage division circuit. The 7th pin is the output terminal, connected to the integration circuit. Specifically, the 5th pin of U7B is connected to the voltage division circuit composed of R10 and R20, and the 7th pin is connected to the integration circuit composed of R18 and C18. When the output terminal of U6A is at a high level, it is divided by R10 and R20, and the integration circuit is connected to the filtering circuit, where the filtering circuit is composed of R27, R19, C19, and R29.

[0038] When the output of U6A is high, it is divided by R10 and R20 to obtain a voltage of about 2V. After being filtered by C17, it is input to pin 5 of U7B. At this time, the PWM at pin 6 of U7B is compared with 2V, and pin 7 follows the inverted PWM of pin 6. When the duty cycle of the PWM at pin 6 of U7B decreases, the duty cycle of pin 7 increases. At this time, after integration by R18 and C18, R27, R19, C19 and R29 form a filtering circuit. After the filtering circuit, there are Q2 and D6. Q2 and D6 are connected in parallel with C20, and then connected to R6, and output through R6; the signal converted from PWM is changed into a stable analog signal, then amplified by Q2, filtered by C11, isolated by D6, filtered by C5. The main function of C20 is to quickly add this signal to the output terminal when starting up, so that the reference of the output terminal is accelerated to be stable and there will be no phenomenon of lamp flashing. R6 adds this signal that changes according to PWM to the voltage reference of the main power supply to achieve: when the PWM duty cycle is lower than 30%, change the constant voltage reference so that the output voltage decreases accordingly. To achieve the function of dim light in the form of step-down.

[0039] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A breeding lamp control circuit that simulates natural light, characterized in that It includes the following: DIM+ and DIM- are external dimming control terminals for inputting control signals. The control signals are input to the analog-to-digital conversion circuit U1, and U1 outputs PWM. U1 has 8 pins. Among them, pins 6 and 7 of U1 output positive and negative PWM, and the driving optocoupler is used to achieve isolation conversion. U1 is connected with optocouplers U2 and U3, and U2 and U3 form a push-pull drive. The 5V voltage is input to the integration circuit of U1 in the form of PWM to achieve the function of digital-to-analog conversion. After being converted and isolated by U1, it is integrated and filtered into a DC voltage and then enters the positive terminal of comparator U4 for current amplification. The output of pin 4 of U4 is output. D2 and D3 are used to limit the reference of the lowest output voltage control signal and retain 10% of the current. D2 and D3 are fed back to the negative terminal of U4. Pins 6 and 7 of U1 output positive and negative PWM, and the driving optocoupler is used to achieve isolation conversion. U1 converts the PWM signal into a variable analog signal through one-way integration, and then passes through a filter circuit and is input to comparator U6A. The PWM is divided into three paths: the first path is filtered into a DC voltage by the integration circuit and then enters the positive terminal of U4. After current amplification, it is output and applied to the constant current control circuit of the main power supply to realize the change of current into the change of the brightness of the LED lamp. The second path of the PWM signal also passes through the integration circuit and is applied to U6A to realize the switching circuit of current adjustment and voltage adjustment. The third path of the PWM is applied to comparator U7B to realize the inversion of the duty cycle of the PWM and is output after being inverted by U7B. The positive terminal of U6A is used as a reference for the switching circuit. Diode D4 and resistor R7 form a window comparator and are connected to the positive terminal of U6A. When the output terminal is at a high level of 12V, 12V is fed back to the positive terminal of U6A through D4 and R7, making the voltage at the positive terminal of U6A higher. U6A is connected with U7B. Pin 6 of U7B is the negative terminal, connected to PWM. Pin 5 is the positive terminal, connected to the voltage division circuit. Pin 7 is the output terminal, connected to the integration circuit. When the output terminal of U6A is high, it is voltage-divided by the voltage division circuit to obtain a 2V voltage. After being filtered by capacitor C17, it is input to pin 5 of U7B. At this time, the PWM at pin 6 of U7B is compared with 2V, and pin 7 follows the inverted PWM of pin 6. When the duty cycle of the PWM at pin 6 of U7B decreases, the duty cycle of pin 7 increases. At this time, it is integrated by the integration circuit and then passes through the filter circuit to convert the signal converted from PWM into a stable analog signal. After the filter circuit, there are transistor Q2 and diode D6. Q2 and D6 are connected in parallel with capacitor C20 and then connected with resistor R6, and the output is through R6.

2. The aquaculture lamp control circuit simulating natural light according to claim 1, characterized in that There are diode D1 and resistor R1 connected between DIM+ and U1. Among them, D1 is used to prevent U1 from being burned out when there is high voltage outside. R1 acts as a buffer. There is resistor R3 set between DIM+ and DIM-. R3 is used for discharging to quickly discharge the voltage at pin 3 of U1 when power is off.

3. The aquaculture lamp control circuit for simulating natural light according to claim 1, characterized in that Variable resistors, 0 - 10V dimmers, and PWM can all be used as control signals and are input through DIM+ and DIM-.

4. The aquaculture lamp control circuit simulating natural light according to claim 1, characterized in that Resistor R12 and capacitor C3. Resistor R12 is connected after U2 and U3, capacitor C3 is grounded, resistor R9 is connected to R12, and capacitor C4 is grounded.

5. The aquaculture lamp control circuit for simulating natural light according to claim 4, characterized in that The output of pin 4 of U4. Diodes D2 and D3 are connected between the output terminal of U4 and the grounded terminal 3. At the same time, D2 and D3 are fed back to the negative terminal of U4.

6. The aquaculture lamp control circuit simulating natural light according to claim 5, wherein A resistor R22 is connected in series with pin 3 of U4. D2, D3, and R22 form a loop to ensure that the voltage fed back to pin 3 of U4 is 1.2V lower than the output terminal.

7. The aquaculture lamp control circuit simulating natural light according to claim 6, characterized in that Resistors R5, R13, and thermistor RT1 are connected to pin 4 of U4 to form a voltage - dividing circuit. At the same time, capacitor C5 is also connected to pin 4 of U4. C5 filters the output and gives it to the control reference of the constant - current power supply to achieve the function of dimming constant current.

8. The aquaculture lamp control circuit for simulating natural light according to claim 1, wherein Transistor Q4, capacitor C8, resistor R14, diode U5, resistor R15, resistor R16, and capacitor C9 form a 5V voltage - stabilizing circuit, and the 5V voltage - stabilizing circuit supplies power to the isolated PWM; transistor Q1, resistor R26, zener diode ZD1, capacitor C15, and capacitor C16 form a 12V voltage - stabilizing circuit, and the 12V voltage - stabilizing circuit supplies power to U6.

9. The aquaculture lamp control circuit for simulating natural light according to claim 8, wherein Diodes D5, resistor R21, resistor R11, resistor RC12, and resistor R23 form an integrating circuit to convert the PWM signal into a variable analog signal. Resistor R17 and capacitor C13 form a filtering circuit to stabilize the voltage input to the negative terminal of U6A. The function of D5 is isolation to prevent the integrated voltage from returning to the PWM circuit.

10. The aquaculture lamp control circuit for simulating natural light according to claim 1, wherein Pin 5 of U7B is connected to the voltage - dividing circuit R10 and R20, and pin 7 is connected to the integrating circuit R18, C18. When the output terminal of U6A is high, it is divided by R10 and R20, and the integrating circuit is connected to the filtering circuit, where the filtering circuit is composed of R27, R19, C19, and R29.

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