CN216873429U - High-response high-linearity dimming circuit - Google Patents
High-response high-linearity dimming circuit Download PDFInfo
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- CN216873429U CN216873429U CN202220668737.0U CN202220668737U CN216873429U CN 216873429 U CN216873429 U CN 216873429U CN 202220668737 U CN202220668737 U CN 202220668737U CN 216873429 U CN216873429 U CN 216873429U
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Abstract
The utility model belongs to the field of dimming circuits, and discloses a high-response high-linearity dimming circuit which comprises a power supply for supplying power to each module of the dimming circuit, and an MCU module for receiving and identifying externally input differential signals, automatically dividing the differential signals into PWM brightness dimming signals and PWM flicker dimming signals according to the application of the differential signals, and respectively outputting the PWM brightness dimming signals and the PWM flicker dimming signals; the constant current control module is used for receiving the PWM brightness dimming signal, converting the PWM brightness dimming signal into an analog dimming signal and outputting a control current which changes along with the analog dimming signal; the electronic switch module is used for receiving the control current and outputting the control current, and is used for receiving the PWM flicker dimming signal and executing corresponding on-off action according to the PWM flicker dimming signal; and the LED lamp group is used for receiving the control current and responding. The circuit structure of the dimming circuit is simple, and the analog dimming and the digital dimming are combined through the automatic identification dimming signal, so that the dimming effect of high linearity and high response is achieved.
Description
Technical Field
The utility model relates to a dimming circuit, in particular to a high-response and high-linearity dimming circuit.
Background
The dimming circuit is mainly used for adjusting the brightness and dynamic change of the LED lamp and is used in a plurality of products. For example, in chinese patent application No. 201610158350X, an ac-driven hybrid dimming circuit is disclosed, in which a voltage/current monitoring module is required to monitor a lamp strip current, thereby outputting a constant current, and in addition, an analog dimming control module and a digital control module need to complete current adjustment and on/off control through a current sampling module during operation, and each of the above modules also needs to be provided with a feedback circuit to a PWM control module to realize corresponding actions, and the circuit can realize combination of analog dimming and PWM dimming, but has a complicated overall structure, and is mainly used for backlight dimming of a liquid crystal television, and is not well suited for dimming of an LED lamp in the photography industry. In the photographic industry, the LED lamp mainly has analog dimming and PWM digital dimming, and the brightness of the LED lamp can be adjusted and the on-off of the LED lamp can be controlled by the two dimming modes, so that the effects of adjusting the light and shade and flickering of the light are realized. The analog dimming adjustment has good linearity, is suitable for adjusting the brightness of light, but has slow response, and has poor on-off flickering effect when used for adjusting the light, while the digital dimming adjustment has opposite effect, and has fast response, is suitable for adjusting the on-off flickering of the light, but has poor linearity, and has poor linearity in the aspect of adjusting the brightness. Both approaches have become increasingly difficult to accommodate for the dimming requirements of the photography industry due to their inherent disadvantages.
Disclosure of Invention
In order to solve the defects of the prior art, the utility model provides the dimming circuit which has a simple structure and effectively combines analog dimming and digital dimming to realize high response and high linearity.
The technical scheme adopted by the utility model for solving the problems is as follows:
a high-response high-linearity dimming circuit comprises a power supply for supplying power to each module of the dimming circuit, and an MCU module for receiving and identifying externally input differential signals, automatically dividing the signals into PWM brightness dimming signals and PWM flicker dimming signals according to the purpose of the differential signals and respectively outputting the signals; the constant current control module is used for receiving the PWM brightness dimming signal output by the MCU module, converting the PWM brightness dimming signal into an analog dimming signal and outputting a control current which changes along with the analog dimming signal; the electronic switch module is used for receiving the control current output by the constant current control module and outputting the control current, and is used for receiving the PWM flicker dimming signal output by the MCU module and executing corresponding on-off action according to the PWM flicker dimming signal; and the LED lamp bank is used for receiving the control current output by the electronic switch module and responding.
According to the technical scheme, the constant current control module comprises a sampling module used for detecting the magnitude of control current output by the constant current control module, and the control current output by the constant current control module is controlled not to exceed the maximum rated current according to data detected by the sampling module.
According to a further improved technical scheme, the constant current control module further comprises a constant current module, wherein a receiving end of the constant current module forms a receiving end of the constant current control module for receiving the PWM brightness dimming signal, an output end of the constant current module forms an output end of the constant current control module for outputting a control current, a detection end of the sampling module is electrically connected with an output end of the constant current module, and a feedback end of the sampling module is electrically connected with the constant current module.
According to the further improved technical scheme, the sampling module comprises resistors R1, R3, R4, R10, R11, a capacitor C7 and an operational amplifier U2, wherein the resistor R1 is connected in series on a circuit for controlling current, two ends of the resistor R3 are respectively connected with one side of high potential of the resistor R1 and the non-inverting input end of the operational amplifier U2, two ends of the resistor R4 are respectively connected with one side of low potential of the resistor R1 and the inverting input end of the operational amplifier U2, the output end of the operational amplifier U2 is connected with the feedback input end of the constant current module after passing through the resistor R10, two ends of the resistor R7 are respectively connected with the non-inverting input end of the operational amplifier U2 and an external reference voltage Vref, two ends of the resistor R11 are respectively connected with the inverting input end and the output end of the operational amplifier U2, one end of the capacitor C7 is connected with one side of low potential of the resistor R10, and the other end is grounded.
According to the further improved technical scheme, the constant current module comprises a driving IC chip which can convert the PWM brightness dimming signal into an analog dimming signal.
According to the further improved technical scheme, the constant current module is a DC-DC constant current module or a linear constant current module.
According to a further improved technical scheme, the electronic switch module is a switch module comprising an MOS (metal oxide semiconductor) tube.
The utility model has the beneficial effects that: according to the LED dimming control circuit, differential signals input from the outside are identified through the MCU module, if the signals are used for adjusting brightness, the differential signals are transmitted to the constant current control module, the constant current control module converts the PWM brightness dimming signals into analog dimming signals, control currents which can change along with the analog dimming signals are generated, and the control currents are output to the LED lamp set through the electronic switch module, so that linear dimming of light and shade of lamp light is achieved; if the signal for adjusting the on-off flicker is transmitted to the electronic switch module, the on-off of the electronic switch module is directly controlled, so that the light is on or off to generate a flicker effect; the dimming circuit is simple in circuit structure, combines analog dimming and PWM dimming through automatically identifying dimming signals, and achieves high-linearity and high-response dimming effect.
Drawings
FIG. 1 is a block diagram of the circuit of the present invention;
fig. 2 is a specific circuit diagram of the present invention.
Detailed Description
The conception, the specific structure and the technical effects of the present invention will be clearly and completely described in the following with reference to the embodiments and the accompanying drawings, so as to fully understand the objects, the features and the effects of the present invention. The technical characteristics in the utility model can be interactively combined to form a new embodiment on the premise of not conflicting with each other.
The embodiment of the high-response and high-linearity dimming circuit shown in fig. 1 includes an MCU module 2, a constant current control module 3, an electronic switch module 4, an LED lamp set 5, and a power supply 1. Wherein the power supply 1 is used for supplying power to each module of the whole dimming circuit, and belongs to the prior art. The MCU module 2 has two paths of outputs which are respectively connected with the constant current control module 3 and the electronic switch module 4, and the input end of the MCU module is mainly used for receiving differential signals input from the outside, and then automatically dividing the differential signals into PWM brightness dimming signals and PWM flicker dimming signals according to the purpose of the differential signals and respectively outputting the PWM brightness dimming signals and the PWM flicker dimming signals to the constant current control module 3 and the electronic switch module 4. The constant current control module 3 converts the PWM brightness dimming signal into an analog dimming signal after receiving the PWM brightness dimming signal output by the MCU module 2, and outputs a control current varying with the analog dimming signal, and the control current flows to the LED lamp set 5 through the electronic switch module 4. Because the control current is changed along with the analog dimming signal, the brightness of the LED lamp set 5 is adjusted to be more linear, and the effect is better. If the differential signal is used for adjusting the light to be on or off and twinkling, the MCU module 2 outputs a PWM (pulse-width modulation) flickering and dimming signal, the PWM flickering and dimming signal directly flows to the electronic switch module 4 after being output, the electronic switch module 4 can execute corresponding on-off action after receiving the PWM flickering and dimming signal, and the LED lamp group 5 has the flickering effect of being on or off through the on-off action. The electronic switch module 4 preferably adopts a switch module comprising an MOS (metal oxide semiconductor) tube, the MOS tube has high response speed, and can quickly respond to a PWM (pulse-width modulation) flicker dimming signal to execute on-off action, so that the dimming action is quicker.
In the above embodiment, in order to prevent the control current from being too large and exceeding the maximum rated current, the sampling module 31 may be configured to detect the control current and feed back the detection information. Specifically, the sampling module 31 is used as a sub-module of the constant current control module 3, the sampling module 31 feeds back current data to the constant current control module 3 after detecting the control current at the output end of the constant current control module 3, and the constant current control module 3 controls the control current not to exceed the rated current according to the current data. In addition, in addition to the sampling module 31, the constant current control module 3 further includes a sub-module of the constant current module 32, and the constant current module 32 is mainly used for outputting a control current, wherein a receiving end of the constant current module 32 is used for receiving the PWM brightness dimming signal, the receiving end is a receiving end of the constant current control module 3 for receiving the PWM brightness dimming signal, an output end of the constant current module 32 is used for outputting the control current, and the output end is an output end of the constant current control module 3 for outputting the control current. In the constant current control module 3, a detection end of the sampling module 31 is electrically connected with an output end of the constant current module 32, a feedback end of the sampling module 31 is electrically connected with the constant current module 32, the sampling module 31 feeds back a control current output by the constant current module 32 to the constant current module 32 after detecting the control current, and the constant current module 32 adjusts the control current according to the feedback current data. In addition, the constant current module 32 is a DC-DC constant current module or a linear constant current module.
Referring to fig. 2, in a specific embodiment of a dimming circuit, in the circuit, U1 is a driver IC chip, and specifically, an FP7209 single chip microcomputer is used, and the single chip microcomputer of the type can convert a PWM brightness dimming signal into an analog dimming signal. U3 adopts M483SIDAE singlechip, U2 adopts RS8512XK operational amplifier. The sampling module 31 comprises resistors R1, R3, R4, R10, R11, a capacitor C7 and an operational amplifier U2, wherein the resistor R1 is connected in series to a line for controlling current, two ends of the resistor R3 are respectively connected with one side of the resistor R1 with high potential and the non-inverting input end of the operational amplifier U2, two ends of the resistor R4 are respectively connected with one side of the resistor R1 with low potential and the inverting input end of the operational amplifier U2, and the output end of the operational amplifier U2 is connected to the feedback input end of the constant current module, namely, the FB pin of U1 after passing through the resistor R10; in addition, two ends of the R7 are respectively connected with a non-inverting input end of an operational amplifier U2 and an external reference voltage Vref, two ends of the resistor R11 are respectively connected with an inverting input end and an output end of an operational amplifier U2, one end of the capacitor C7 is connected with one side of the resistor R10 with low potential, and the other end of the capacitor C7 is grounded.
When the LED lamp works, power supply current is converted into an adjustable constant current source through the constant current module and then is output to the LED lamp bank as control current, the control current is subjected to real-time monitoring of the control current through the sampling resistor R1 and the R1 and is converted into a voltage signal, the sampling signal is subjected to proportional operation through the resistors R3, R4, R7, R11, R10 and U2 and then is output to the FB pin of the U1, and at the moment, the voltage Vfb of the FB pin is in a positive proportional relation with the control current I.
When a differential signal input by the outside is input into the U3, the differential signal is automatically divided into a PWM brightness dimming signal and a PWM flicker dimming signal and is respectively output from a PB13/DACO pin and a PA1 pin, wherein the PWM brightness dimming signal is input from a DIM pin of the U1, the U1 converts the PWM brightness dimming signal into an analog dimming signal, and at the moment, the duty ratio of a field effect transistor Q1 is adjusted in real time according to the analog dimming signal and a Vfb signal inside the U1, so that the control current I follows the analog dimming signal, and the analog adjustment is realized. If the U3 recognizes that the WM dimming signal is a PWM flicker dimming signal, the PWM flicker dimming signal is output from the PA1 pin to the Q2. When the PWM flicker dimming signal is at a high level, the field effect transistor Q2 is quickly switched on, and at the moment, the control current flows through the LED lamp bank, and the LED lamp bank is quickly lightened; when the PWM flicker dimming signal is at a low level, the field effect transistor Q2 is cut off rapidly, the circuit is disconnected at the moment, and the LED lamp bank is turned off rapidly.
It should be noted that the above-mentioned embodiments are only used for further illustration of the present invention, and should not be construed as limiting the scope of the present invention, and if the present technology is simply modified, the objects of the present invention can be achieved by substantially the same means, and all of the objects should fall within the scope of the present invention.
Claims (7)
1. A high-response high-linearity dimming circuit, characterized in that: comprises a power supply (1) for supplying power to each module of the dimming circuit and further comprises,
the MCU module (2) is used for receiving and identifying differential signals input from the outside, automatically dividing the differential signals into PWM brightness dimming signals and PWM flicker dimming signals according to the purpose of the differential signals and respectively outputting the PWM brightness dimming signals and the PWM flicker dimming signals;
the constant current control module (3) is used for receiving the PWM brightness dimming signal output by the MCU module (2), converting the PWM brightness dimming signal into an analog dimming signal and outputting a control current which changes along with the analog dimming signal;
the electronic switch module (4) is used for receiving the control current output by the constant current control module (3) and outputting the control current, and is used for receiving the PWM flicker dimming signal output by the MCU module (2) and executing corresponding on-off action according to the PWM flicker dimming signal;
and the LED lamp bank (5) is used for receiving the control current output by the electronic switch module (4) and responding.
2. The high-response high-linearity dimming circuit according to claim 1, wherein: the constant current control module (3) comprises a sampling module (31) for detecting the magnitude of control current output by the constant current control module, and the control current output by the constant current control module (3) is controlled not to exceed the maximum rated current according to data detected by the sampling module (31).
3. The high-response high-linearity dimming circuit according to claim 2, wherein: the constant current control module (3) further comprises a constant current module (32), the receiving end of the constant current module (32) forms a receiving end of the constant current control module (3) for receiving the PWM brightness dimming signal, the output end of the constant current module (32) forms an output end of the constant current control module (3) for outputting a control current, the detection end of the sampling module (31) is electrically connected with the output end of the constant current module (32), and the feedback end of the sampling module (31) is electrically connected with the constant current module (32).
4. A high-response high-linearity dimming circuit as claimed in claim 3, wherein: the sampling module (31) comprises resistors R1, R3, R4, R7, R10, R11, a capacitor C7 and an operational amplifier U2, wherein the resistor R1 is connected in series on a circuit for controlling current, two ends of the resistor R3 are respectively connected with one side of high potential of the resistor R1 and the non-inverting input end of an operational amplifier U2, two ends of the resistor R4 are respectively connected with one side of low potential of the resistor R1 and the inverting input end of the operational amplifier U2, the output end of the operational amplifier U2 is connected with the feedback input end of the constant current module (32) after passing through the resistor R10, two ends of the resistor R7 are respectively connected with the non-inverting input end of the operational amplifier U2 and an external reference voltage Vref, two ends of the resistor R11 are respectively connected with the inverting input end and the output end of the operational amplifier U2, one end of the capacitor C7 is connected with one side of low potential of the resistor R10, and the other end is grounded.
5. A high-response high-linearity dimming circuit as claimed in claim 3, wherein: the constant current module (32) comprises a driving IC chip which can convert the PWM brightness dimming signal into an analog dimming signal.
6. A high-response high-linearity dimming circuit as claimed in claim 3, wherein: the constant current module (32) is a DC-DC constant current module (32) or a linear constant current module (32).
7. The high-response high-linearity light modulation circuit according to any one of claims 1 to 6, wherein: the electronic switch module (4) is a switch module comprising an MOS tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220668737.0U CN216873429U (en) | 2022-03-26 | 2022-03-26 | High-response high-linearity dimming circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220668737.0U CN216873429U (en) | 2022-03-26 | 2022-03-26 | High-response high-linearity dimming circuit |
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| CN216873429U true CN216873429U (en) | 2022-07-01 |
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| CN202220668737.0U Active CN216873429U (en) | 2022-03-26 | 2022-03-26 | High-response high-linearity dimming circuit |
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