Device for isolating, enhancing and correcting PWM (Pulse Width Modulation) driving signal

Abstract

The utility model provides a device for isolating, enhancing and correcting PWM (Pulse Width Modulation) driving signals. The device comprises a signal enhancing and amplifying unit, a signal isolating and transmitting unit, a signal correcting unit, a rising driving signal enhancing unit and a falling driving signal enhancing unit, the input end of the signal enhancing and amplifying unit is connected with a PWM signal, and the output end of the signal enhancing and amplifying unit is connected with the input end of the signal isolating and transmitting unit; the input end of the correction signal unit is connected with the output end of the isolation transmission signal unit, and the output end of the correction signal unit is connected with the output end of the ascending driving signal enhancement unit and the output end of the descending driving signal enhancement unit. The device can be applied to any PWM isolation dimming product, PWM signals can be enhanced and corrected only by adding the device to any isolated dimming power supply product, the effects of reducing signal distortion and optimizing the dimming effect can be really achieved, and the dimming product has higher market competitiveness.

Description

Technical Field

[0001] The utility model belongs to the technical field of PWM signal isolation, enhancement and correction, and in particular relates to a device for isolating, enhancing and correcting a PWM driving signal. Background Art

[0002] In the prior art, many isolated PWM drive signals do not have enhancement and correction, so that when the PWM signal driven by a small signal is output, the waveform will be seriously distorted and the driving ability will be weak, which will affect the dimming efficiency, dimming effect, dimming smoothness, etc. when driving the MOS tube. For example: constant voltage and constant current thyristor dimming belongs to the front stage sampling output PWM signal, the rear stage driving dimming product, the isolated 0-10V dimming output and signal are isolated, so many dimming LED power products will have a rough dimming effect in the low and medium end, heavy graininess, poor comfort, etc. Such products are not suitable for the high-end market and some high-end places such as hotels, subways, luxury houses, etc. In order to achieve the dimming effect, some non-isolated solutions are made. The non-isolated solution has small PWM waveform distortion without isolation and good dimming effect, but the non-isolated product is a high voltage product, which is unsafe and prone to leakage and fire. Utility Model Content

[0003] In order to overcome the above technical defects, the utility model provides a device for isolating, enhancing and correcting a PWM driving signal, which improves the dimming performance.

[0004] The utility model is realized by the following scheme:

[0005] A device for isolating, enhancing and correcting a PWM drive signal, comprising:

[0006] An enhanced amplification signal unit, an isolation transmission signal unit, a correction signal unit, an upward drive signal enhancement unit, and a downward drive signal enhancement unit;

[0007] The input end of the enhanced amplification signal unit is connected to the PWM signal, and the output end of the enhanced amplification signal unit is connected to the input end of the isolated transmission signal unit; the input end of the correction signal unit is connected to the output end of the isolated transmission signal unit, and the output end of the correction signal unit is connected to the output end of the rising drive signal enhancement unit and the output end of the falling drive signal enhancement unit.

[0008] As a further improvement of the utility model, the enhanced amplified signal unit comprises: a first triode;

[0009] The base of the first transistor is connected to the PWM signal, the emitter of the first transistor is grounded, and the collector of the first transistor is connected to the input end of the isolation transmission signal unit.

[0010] As a further improvement of the utility model, the isolation transmission signal unit includes: a photoelectric coupler, a first resistor;

[0011] The power supply is connected to the first end of the photoelectric coupler through the first resistor, and the second end of the photoelectric coupler is connected to the collector of the first transistor;

[0012] The fourth end of the photoelectric coupler is connected to the input end of the correction signal unit, and the third end of the photoelectric coupler is grounded.

[0013] As a further improvement of the utility model, the correction signal unit includes: a second triode, a second resistor, and a third resistor;

[0014] The third end of the photoelectric coupler is connected to the base of the second transistor, the power supply is connected to the base of the second transistor through the second resistor, the power supply is connected to the collector of the second transistor through the third resistor, the collector of the second transistor is connected to the input end of the rising drive signal enhancement unit, and the emitter of the second transistor is grounded.

[0015] As a further improvement of the utility model, the rising drive signal enhancement unit includes: a third triode and a fourth resistor;

[0016] The collector of the second transistor is connected to the base of the third transistor, the power supply is connected to the base of the third transistor through the fourth resistor, the base of the third transistor is connected to the input end of the falling drive signal enhancement unit, the power supply is connected to the collector of the third transistor, and the emitter of the third transistor is connected to the output end of the falling drive signal enhancement unit.

[0017] As a further improvement of the utility model, the falling drive signal enhancement unit includes: a fourth triode;

[0018] The base of the fourth transistor is connected to the base of the third transistor, the emitter of the fourth transistor is connected to the emitter of the third transistor, and the collector of the fourth transistor is grounded.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows: the input PWM signal is passed through the enhanced amplification signal unit to achieve enhanced amplification of the signal, and then the signal is transmitted to the correction signal unit through the isolation transmission signal unit to correct the rising and falling signals, and finally the signal is enhanced by the rising drive signal enhancement unit and the falling drive signal enhancement unit. Through the setting of the above units, the waveform of the final output can be free of distortion, thereby achieving the function of enhancing and correcting the PWM drive signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 It is a schematic diagram of the overall structure of the device described in the utility model;

[0022] Figure 2 It is a schematic diagram of PWM waveform output in the prior art;

[0023] Figure 3 This is a schematic diagram of the PWM waveform output of the device described in the utility model.

[0024] Reference numerals: 1. Enhanced amplification signal unit; 2. Isolation transmission signal unit; 3. Correction signal unit; 4. Rising drive signal enhancement unit; 5. Falling drive signal enhancement unit. DETAILED DESCRIPTION

[0025] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0026] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0027] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0028] The utility model provides a device for isolating, enhancing and correcting PWM drive signals, such as Figure 1As shown, it includes: an enhanced amplification signal unit 1, an isolation transmission signal unit 2, a correction signal unit 3, an upward drive signal enhancement unit 4 and a downward drive signal enhancement unit 5; the input end of the enhanced amplification signal unit 1 is connected to the PWM signal, and the output end of the enhanced amplification signal unit 1 is connected to the input end of the isolation transmission signal unit 2; the input end of the correction signal unit 3 is connected to the output end of the isolation transmission signal unit 2, and the output end of the correction signal unit 3 is connected to the output end of the upward drive signal enhancement unit 4 and the output end of the downward drive signal enhancement unit 5.

[0029] The enhanced signal amplification unit 1 includes: a first transistor Q1; the base of the first transistor Q1 is connected to the PWM signal, the emitter of the first transistor Q1 is grounded, and the collector of the first transistor Q1 is connected to the input end of the isolation transmission signal unit 2. The enhanced signal amplification unit 1 composed of the first transistor Q1 is used to amplify the input PWM signal.

[0030] The isolated transmission signal unit 2 includes: a photoelectric coupler U1 and a first resistor R1; the power supply is connected to the first end of the photoelectric coupler U1 through the first resistor R1, and the second end of the photoelectric coupler U1 is connected to the collector of the first transistor Q1; the fourth end of the photoelectric coupler U1 is connected to the input end of the correction signal unit 3, and the third end of the photoelectric coupler U1 is grounded.

[0031] The correction signal unit 3 includes: a second transistor Q2, a second resistor R2, and a third resistor R3; the third end of the photocoupler U1 is connected to the base of the second transistor Q2, the 5V DC power supply is connected to the base of the second transistor Q2 through the second resistor R2, the 5V DC power supply is connected to the collector of the second transistor Q2 through the third resistor R3, the collector of the second transistor Q2 is connected to the input end of the rising drive signal enhancement unit 4, and the emitter of the second transistor Q2 is grounded.

[0032] The rising driving signal enhancing unit 4 includes: a third triode Q3 and a fourth resistor R4; the collector of the second triode Q3 is connected to the base of the third triode Q3, the power supply VCC is connected to the base of the third triode Q3 through the fourth resistor R4, the base of the third triode Q3 is connected to the input end of the falling driving signal enhancing unit 5, the power supply VCC is connected to the collector of the third triode Q3, and the emitter of the third triode Q3 is connected to the output end of the falling driving signal enhancing unit 5. The third triode Q3 mainly plays the role of signal amplification and enhancement.

[0033] The falling driving signal enhancement unit 5 includes: a fourth transistor Q4; the base of the fourth transistor Q4 is connected to the base of the third transistor Q3, the emitter of the fourth transistor Q4 is connected to the emitter of the third transistor Q3, and the collector of the fourth transistor Q4 is grounded. The fourth transistor Q4 mainly plays the role of signal amplification and enhancement.

[0034] Next, the utility model is further explained in combination with the specific working principle, as follows:

[0035] After the input PWM signal is enhanced and amplified by the first transistor Q1, the transmission capacity of the photocoupler U1 is enhanced, so that the signal transmission can quickly charge the junction capacitance of the photocoupler U1 itself, and accelerate the rise and fall speed of the transmitted signal. Ensure that the distortion of the previous transmission signal is small. After the signal is transmitted by the photocoupler U1. The photocoupler U1 itself will be distorted during transmission. In order to reduce the distortion, the signal cannot be directly output through the photocoupler U1. Let the signal pass through the second transistor Q2, the second resistor R2, and the third resistor R3 for correction and output. The principle is: the signal is not directly output, but the U1 signal is used to control the base of the second transistor Q2. The base of the second transistor Q2 is connected to the power supply VCC through the second resistor R2. Because the resistor has no junction capacitance and will not cause signal distortion, the voltage of the power supply VCC will not be distorted after passing through the resistor, thereby controlling the base of the second transistor Q2. The signal will not be distorted, the second transistor Q2 will not be distorted when it is turned on or off. The output signal is connected to the power supply VCC through the collector of the second transistor Q2 and the third resistor R3. When the second transistor Q2 control signal is turned off, the power supply VCC signal is output through the third resistor R3. The output signal is equal to the power supply VCC and will not be distorted. When the second transistor Q2 control signal is turned on, the collector of the second transistor Q2 is directly grounded, so that all the electricity can be connected to the ground instantly. In this way, the low-level output signal is the ground, and the ground signal will not be distorted. Figure 2 It is a signal that has not been processed by the second transistor Q2, the second resistor R2, and the third resistor R3. After being processed by the second transistor Q2, the second resistor R2, and the third resistor R3, the signal is obtained as follows Figure 3 signal, thus eliminating the problem of signal waveform distortion caused by the response speed of the optocoupler U1 itself.

[0036] At the same time, in order to enhance the external driving capability of the signal without being affected, a third transistor Q3 is added to amplify and enhance the driving current of the driving signal at the rising edge, and a fourth transistor Q4 is added to amplify and enhance the driving current at the falling edge.

[0037] like Figure 2 and Figure 3 As shown, the output waveform of the prior art and the output waveform of the present invention.

[0038] In summary, the utility model has the following technical effects:

[0039] Based on the working principle of transistor saturation conduction and transmission speed characteristics of optocoupler, the utility model designs a device for isolating, enhancing and correcting PWM drive signals, which can eliminate waveform distortion and enhance the external driving ability of the signal. The device can be applied to any PWM isolated dimming product. As long as the device is added to any isolated dimming power supply product, the PWM signal can be enhanced and corrected, which can truly reduce signal distortion, optimize the dimming effect, and make the dimming product more competitive in the market.

[0040] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A device for isolating, enhancing and correcting a PWM drive signal, characterized in that: include: Enhanced amplification signal unit, isolated transmission signal unit, correction signal unit, rising drive signal enhancement unit and falling drive signal enhancement unit; The input end of the enhanced amplification signal unit is connected to the PWM signal, and the output end of the enhanced amplification signal unit is connected to the input end of the isolated transmission signal unit; the input end of the correction signal unit is connected to the output end of the isolated transmission signal unit, and the output end of the correction signal unit is connected to the output end of the rising drive signal enhancement unit and the output end of the falling drive signal enhancement unit.

2. The device according to claim 1, characterized in that The signal enhancement and amplification unit includes: a first transistor; The base of the first transistor is connected to the PWM signal, the emitter of the first transistor is grounded, and the collector of the first transistor is connected to the input end of the isolation signal transmission unit.

3. The device according to claim 2, characterized in that The isolation signal transmission unit includes: a photoelectric coupler and a first resistor; The power supply is connected to the first end of the photoelectric coupler through the first resistor, and the second end of the photoelectric coupler is connected to the collector of the first transistor; The fourth end of the photoelectric coupler is connected to the input end of the correction signal unit, and the third end of the photoelectric coupler is grounded.

4. The device according to claim 3, characterized in that The correction signal unit includes: a second transistor, a second resistor, and a third resistor; The third end of the photoelectric coupler is connected to the base of the second transistor, the power supply is connected to the base of the second transistor through the second resistor, the power supply is connected to the collector of the second transistor through the third resistor, the collector of the second transistor is connected to the input end of the rising drive signal enhancement unit, and the emitter of the second transistor is grounded.

5. The device according to claim 4, characterized in that The rising drive signal enhancement unit includes: a third transistor and a fourth resistor; The collector of the second transistor is connected to the base of the third transistor, the power supply is connected to the base of the third transistor through the fourth resistor, the base of the third transistor is connected to the input end of the falling drive signal enhancement unit, the power supply is connected to the collector of the third transistor, and the emitter of the third transistor is connected to the output end of the falling drive signal enhancement unit.

6. The device according to claim 5, characterized in that The falling drive signal enhancing unit includes: a fourth transistor; The base of the fourth transistor is connected to the base of the third transistor, the emitter of the fourth transistor is connected to the emitter of the third transistor, and the collector of the fourth transistor is grounded.

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