CN114487542A - A kind of thyristor dimmer intelligent detection method, circuit and driving circuit thereof - Google Patents

Abstract

The invention discloses an intelligent detection circuit of a silicon controlled rectifier dimmer, which comprises a detection circuit, wherein the detection circuit comprises: the sampling module is used for generating a first voltage signal representing the magnitude of the direct-current bus voltage; the detection module comprises a first comparator and a second comparator, wherein two input ends of the first comparator and the second comparator are respectively connected with a first voltage signal and a second voltage signal, the second voltage signal is close to the first voltage signal in size and has a phase difference of preset time, offset voltage is added into the input ends of the first comparator and the second comparator to make up voltage difference, the output of the first comparator and the output of the second comparator are kept constant when sudden change caused by the silicon controlled dimmer is not detected, and opposite potential signals are output when sudden change caused by the silicon controlled dimmer is detected. Compared with the prior art, the detection module provided by the invention has a simple and reliable implementation mode, can finish the detection of voltage mutation without any other auxiliary circuit and reference voltage, and can simultaneously detect the front chamfer angle and the rear chamfer angle.

Description

A kind of thyristor dimmer intelligent detection method, circuit and driving circuit thereof

technical field

The invention relates to the technical field of power electronics, in particular to an intelligent detection method, circuit and driving circuit of a silicon controlled dimmer.

Background technique

At present, high-voltage linear LED systems mainly use thyristor dimmers to achieve dimming, and to maintain the normal operation of the thyristor dimmers, a holding current is required. In the current solution, some high-voltage linear LED driving solutions will turn on the holding current by default to be compatible with the application scenarios of thyristor dimmers. However, this current will greatly reduce the efficiency of the system, increase the heat dissipation requirement of the system, and thus increase the application cost, which is a problem that the technicians need to solve at present.

SUMMARY OF THE INVENTION

The invention aims to overcome the deficiencies of the prior art, and provides an intelligent detection method, a circuit and a driving circuit thereof for a silicon controlled dimmer.

In order to achieve the above purpose, the present invention provides the following technical solutions: an intelligent detection circuit for a silicon controlled dimmer, used for detecting whether the silicon controlled dimmer is connected to the circuit, including a detection circuit, and the detection circuit includes:

a sampling module, configured to receive the DC bus voltage and generate a first voltage signal representing the magnitude of the DC bus voltage;

The detection module includes a first comparator and a second comparator, two input ends of which are respectively connected to the first voltage signal and a second voltage signal, and the second voltage signal is the same as the first voltage signal. The phase difference is close to and has a preset time, so there is a voltage difference between the first voltage signal and the second voltage signal corresponding to the same time point, and an offset voltage is added to the input terminals of the first comparator and the second comparator to make up for the voltage difference and keep the outputs of the first and second comparators constant when the sudden change caused by the thyristor dimmer is not detected, and when the thyristor dimmer is detected When the sudden change caused by the optical device, the opposite potential signal is output.

In some embodiments, the phase of the second voltage signal lags the phase of the first voltage signal, and the offset voltage is slightly larger than the voltage difference.

所述直流母线电压的周期为f，

In some embodiments, the phase difference of the preset time is denoted as

The period of the DC bus voltage is f,

In some embodiments, the non-inverting input terminal of the first comparator is connected to the first voltage signal, the inverting input terminal is connected to the second voltage signal, and the non-inverting input terminal of the second comparator is connected to For the second voltage signal, the inverting input terminal is connected to the first voltage signal.

In some embodiments, the offset voltage is added to the inverting input terminal of the first comparator, so that the second voltage signal is continuously greater than the first voltage signal in each voltage period, and the second comparator The offset voltage is added to the inverting terminal of the , so that the first voltage signal is continuously greater than the second voltage signal in each voltage period.

In some embodiments, the second voltage signal is obtained from the first voltage signal through a delay circuit, the delay circuit is an RC circuit, and the RC circuit includes a resistor R3 and a capacitor C4, and the resistor R3 is the first One port is connected to the first voltage signal, the non-inverting input of the first comparator, the inverting input of the second comparator, the second port is connected to the inverting input of the first comparator, and then the capacitor is connected The positive pole of C4 is finally connected to the non-inverting input terminal of the second comparator, and the negative pole of the capacitor C4 is grounded.

In some embodiments, the sampling module is composed of a voltage dividing resistor, and the voltage dividing resistor divides the DC bus voltage to obtain the first voltage signal.

In some embodiments, the thyristor dimmer intelligent detection circuit further includes a digital filter for receiving the digital signal output by the detection module, and judging according to whether the sudden change of the digital signal has regularity and periodicity And filter out noise, identify whether the thyristor dimmer is connected to the circuit, and output a control signal to control the switch of maintaining current according to the identification result.

According to another aspect of the present invention, an LED driving circuit is provided, comprising the detection circuit as described above, the detection circuit being connected to the positive terminal voltage of the rectifier bridge.

According to another aspect of the present invention, an intelligent detection method for a silicon controlled dimmer is provided, which is used to detect whether the silicon controlled dimmer is connected to a circuit, comprising the following steps:

receiving the DC bus voltage, and generating a first voltage signal representing the magnitude of the DC bus voltage;

The first voltage signal and a second voltage signal are respectively connected to the two input terminals of the first comparator and the second comparator, and the second voltage signal is close to the first voltage signal and has a preset value. The phase difference of time, so there is a voltage difference between the first voltage signal and the second voltage signal corresponding to the same time point;

An offset voltage is added to the input terminals of the first comparator and the second comparator to compensate for the voltage difference, and the outputs of the first comparator and the second comparator can be adjusted when the thyristor is not detected. The sudden change caused by the light device remains constant, and the opposite potential signal is output when the sudden change caused by the thyristor dimmer is detected.

Beneficial effects of the present invention:

The intelligent detection circuit of the thyristor dimmer of the present invention can detect the voltage sudden change of the DC bus voltage in real time. If the system is connected to the thyristor dimmer, the waveform of the DC bus voltage will be generated by the thyristor dimmer. As shown in Figure 2, the voltage at the cut corner will change abruptly. The detection module of the present invention is simple and reliable, does not need any other auxiliary circuits and reference voltages, only needs two comparators and can generate a phase difference The passive device can complete the detection of voltage mutation, and can detect the front and rear corners at the same time.

Description of drawings

FIG. 1 is a schematic diagram of a partial structure of an LED driving circuit provided by the present invention.

Figure 2 shows the input voltage waveform when the system has a thyristor dimmer.

FIG. 3 is a schematic structural diagram of a detection module of a thyristor dimmer intelligent detection circuit provided by the present invention.

FIG. 4 is the main working waveform of the detection module of the present invention when the system has no thyristor dimmer.

FIG. 5 is the main working waveform of the detection module of the present invention when the system has a thyristor dimmer.

FIG. 6 is a schematic diagram on which the digital filter of the present invention is based.

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.

In the description of the invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" The orientation or positional relationship indicated by , "one side", "the other side", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device or element. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the invention, it should be noted that, unless otherwise expressly specified and limited, the terms "arrangement" and "connection" should be understood in a broad sense. For example, "connection" may be a fixed connection or a detachable connection. It can be connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be specifically understood in specific situations.

The content of the present invention will be described in detail below with reference to the embodiments.

Referring to FIGS. 1-6 , according to an aspect of the present invention, an intelligent detection circuit for a thyristor dimmer is provided for detecting whether the thyristor dimmer is connected to the circuit, including a detection circuit 1 , and the detection circuit 1 includes The sampling module 11 is used to receive the DC bus voltage and generate a first voltage signal representing the magnitude of the DC bus voltage; the detection module 12 includes a first comparator 21 and a second comparator 22, two input ends of which are respectively connected to The first voltage signal V1 and a second voltage signal V2, the second voltage signal V2 and the first voltage signal V1 are similar in size and have a preset time phase difference, so the corresponding There is a voltage difference ΔV between the first voltage signal V1 and the second voltage signal V2, and the offset voltage VOS is added to the input terminals of the first comparator 21 and the second comparator 22 to compensate for the voltage difference ΔV, and make the first comparator 21 and the second comparator 22 input. The outputs of the first comparator 21 and the second comparator 22 remain constant when the sudden change caused by the thyristor dimmer is not detected, and output opposite potentials when the sudden change caused by the thyristor dimmer is detected Signal.

In some embodiments, the phase of the second voltage signal V2 lags the phase of the first voltage signal V1 , and the offset voltage VOS is slightly larger than the voltage difference ΔV.

所述直流母线电压的周期为f，

优选的，

In some embodiments, the phase difference of the preset time is denoted as

The period of the DC bus voltage is f,

preferably,

In some embodiments, the non-inverting input terminal of the first comparator 21 is connected to the first voltage signal V1, the inverting input terminal is connected to the second voltage signal V2, and the non-inverting input terminal of the second comparator 22 is connected to the first voltage signal V1. The input terminal is connected to the second voltage signal V2, and the inverting input terminal is connected to the first voltage signal V1.

In some embodiments, the offset voltage VOS is added to the inverting input terminal of the first comparator 21, so that the second voltage signal V2 is continuously greater than the first voltage signal V1 in each voltage period, and the The offset voltage VOS is added to the inverting terminal of the second comparator 22, so that the first voltage signal V1 is continuously greater than the second voltage signal V2 in each voltage period.

In some embodiments, the second voltage signal V2 is obtained from the first voltage signal V1 through a delay circuit, the delay circuit is an RC circuit, and the RC circuit includes a resistor R3 and a capacitor C4, and the resistor The first port of R3 is connected to the first voltage signal V1 , the non-inverting input terminal of the first comparator 21 , and the inverting input terminal of the second comparator 22 , and the second port is connected to the inverting input terminal of the first comparator 21 , then connect to the positive pole of the capacitor C4, and finally connect to the non-inverting input terminal of the second comparator 22, and the negative pole of the capacitor C4 is grounded.

In some embodiments, the sampling module 11 is composed of a voltage dividing resistor, and the voltage dividing resistor divides the DC bus voltage to obtain the first voltage signal V1. As shown in Figure 3, if the system does not have a thyristor dimmer, the voltage divider V1 of the positive terminal after the rectifier bridge passes through the RC delay circuit and the waveforms of V1 and V2 are shown in Figure 4. There is a voltage between V1 and V2. There is a phase difference, so the corresponding voltages V1 and V2 at the same time point have a ΔV. Connect the two comparators that detect sudden changes in voltage as shown in Figure 3. In this embodiment, the input terminals of the first comparator 21 and the second comparator 22 are respectively connected to the first voltage signal V1 and the second voltage signal V2, and the same voltage signal is connected to the first comparator 21 and the second comparator Therefore, the offset voltage VOS is added to the inverting input terminals of the first comparator 21 and the second comparator 22, and VOS is greater than ΔV, then the system has no thyristor dimmer when the two comparators are The outputs are all low. It can be understood that, the way in which the first voltage signal V1 and the second voltage signal V2 are connected to the first comparator 21 and the second comparator 22, and the input terminal to which the offset voltage VOS is added can be properly adjusted according to the actual situation, so that all The outputs of the first comparator 21 and the second comparator 22 remain constant when the sudden change caused by the thyristor dimmer is not detected, and the outputs are opposite when the sudden change caused by the thyristor dimmer is detected. The potential signal can be. When there is a thyristor dimmer in the system, the thyristor will cut the waveform of the input voltage. At the cut corner of the input voltage, the sudden change of the voltage will immediately reflect the first voltage signal V1, and the second voltage signal V2. A sudden change in the input voltage is not immediately received. Therefore, the first voltage signal V1 and the second voltage signal V2 connected to the input terminal of the comparator will generate a voltage difference at the cut angle of the input voltage caused by the thyristor dimmer. It becomes a high level in a short time, and the main working principle waveform is shown in Figure 5. The offset voltage VOS is added to the inverting input terminal of the first comparator 21, so that the second voltage signal V2 is continuously greater than the first voltage signal V1 in each voltage period, the comparator outputs a low level, and the previous When the cut signal comes, the first voltage signal V1 suddenly changes and is larger than the second voltage signal V2 in a short time, and the output of the first comparator 21 becomes a high level at this time, so as to detect the cycle generated by the thyristor dimmer Sexual precut signal. The offset voltage VOS is added to the inverting terminal of the second comparator 22, so that the first voltage signal V1 is continuously greater than the second voltage signal V2 in each voltage period, the comparator outputs a low level, and then switches When the signal comes, the first voltage signal V1 suddenly changes and is smaller than the second voltage signal V2 in a short time. At this time, the output of the second comparator 22 becomes a high level, so as to detect the periodicity generated by the thyristor dimmer. back-cut signal.

In some embodiments, the thyristor dimmer intelligent detection circuit further includes a digital filter 2 for receiving the digital signal output by the detection module 12, according to whether the sudden change of the digital signal has regularity and periodicity to determine and filter noise, identify whether the thyristor dimmer is connected to the circuit, and output a control signal to control the switch of maintaining current according to the identification result. As shown in Figure 6, the sudden change of voltage caused by the dimmer occurs at the same moment in each cycle of the input voltage, while the sudden change of voltage caused by noise is irregular and random in each cycle of the input voltage. According to this feature, the filtering algorithm of digital filter 2 shields the noise and achieves the purpose of intelligently detecting whether there is a thyristor dimmer in the system.

According to another aspect of the present invention, an LED driving circuit is provided, including the detection circuit as described above, and the detection module 12 is connected to the positive terminal voltage of the rectifier bridge 3 . The detection module 12 in the present invention will detect the sudden change of the voltage at the rear positive end of the rectifier bridge 3 in real time. If the system is connected to a thyristor dimmer, the voltage waveform of the positive end of the rectifier bridge 3 will be generated by the thyristor dimmer. The cut corner of , as shown in Figure 2, the voltage at the cut corner will change abruptly. After the detection module 12 detects the sudden change of the voltage, it outputs the detection result to the digital filter 2. After the digital filter 2 receives the detection result of the comparator, it determines whether the detection result of the detection module is caused by noise or a thyristor adjustment through a filtering algorithm. If it is caused by the thyristor dimmer, the output result of the digital filter 2 will turn on the thyristor maintenance current to make the thyristor dimmer work normally. If it is caused by the input voltage noise, the digital filter 2 will filter out the false detection result caused by the input voltage noise, and will not turn on the holding current, thereby reducing the system power consumption and heat dissipation conditions.

According to another aspect of the present invention, an intelligent detection method for a silicon controlled dimmer is provided, which is used to detect whether the silicon controlled dimmer is connected to a circuit, comprising the following steps:

receiving the DC bus voltage, and generating a first voltage signal representing the magnitude of the DC bus voltage;

The first voltage signal and a second voltage signal are respectively connected to the two input terminals of the first comparator and the second comparator, and the second voltage signal is close to the first voltage signal and has a preset value. The phase difference of time, so there is a voltage difference between the first voltage signal and the second voltage signal corresponding to the same time point;

An offset voltage is added to the input terminals of the first comparator and the second comparator to compensate for the voltage difference, and the outputs of the first comparator and the second comparator can be adjusted when the thyristor is not detected. The sudden change caused by the light device remains constant, and the opposite potential signal is output when the sudden change caused by the thyristor dimmer is detected.

The intelligent detection method of the thyristor dimmer may also have other steps and corresponding advantages as described above, which will not be repeated here.

The embodiments in the above-mentioned embodiments can be further combined or replaced, and the embodiments are only to describe the preferred embodiments of the present invention, and not to limit the concept and scope of the present invention. Various changes and improvements made to the technical solutions of the present invention by professional and technical personnel all belong to the protection scope of the present invention.

Claims (10)

1. A thyristor dimmer intelligent detection circuit is used to detect whether the thyristor dimmer is connected to the circuit, it is characterized in that, the thyristor dimmer intelligent detection circuit comprises a detection circuit, the The detection circuit includes: a sampling module, configured to receive the DC bus voltage and generate a first voltage signal representing the magnitude of the DC bus voltage; The detection module includes a first comparator and a second comparator, two input ends of which are respectively connected to the first voltage signal and a second voltage signal, and the second voltage signal is the same as the first voltage signal. The phase difference is close to and has a preset time, so there is a voltage difference between the first voltage signal and the second voltage signal corresponding to the same time point, and an offset voltage is added to the input terminals of the first comparator and the second comparator to make up for the voltage difference and keep the outputs of the first and second comparators constant when the sudden change caused by the thyristor dimmer is not detected, and when the thyristor dimmer is detected When the sudden change caused by the optical device, the opposite potential signal is output. 2 . The intelligent detection circuit of a silicon controlled dimmer according to claim 1 , wherein the phase of the second voltage signal lags behind the phase of the first voltage signal, and the offset voltage is slightly greater than the voltage difference. 3. The intelligent detection circuit of a silicon controlled dimmer according to claim 2, wherein the phase difference of the preset time is recorded as

The period of the DC bus voltage is f,

4 . The intelligent detection circuit of a silicon controlled dimmer according to claim 3 , wherein the non-inverting input terminal of the first comparator is connected to the first voltage signal, and the inverting input terminal is connected to the first voltage signal. 5 . For the second voltage signal, the non-inverting input terminal of the second comparator is connected to the second voltage signal, and the inverting input terminal is connected to the first voltage signal. 5 . The intelligent detection circuit of a silicon controlled dimmer according to claim 4 , wherein the offset voltage is added to the inverting input end of the first comparator, so that the second voltage signal is at 5 . 6 . The offset voltage is added to the inverting terminal of the second comparator so that the first voltage signal is continuously greater than the second voltage signal in each voltage period. 6 . The intelligent detection circuit for a silicon controlled dimmer according to claim 5 , wherein the second voltage signal is obtained after the first voltage signal is passed through a delay circuit, and the delay circuit is 6 . RC circuit, the RC circuit includes a resistor R3 and a capacitor C4, the first port of the resistor R3 is connected to the first voltage signal, the non-inverting input of the first comparator, the inverting input of the second comparator, and the second The port is connected to the inverting input terminal of the first comparator, then to the positive pole of the capacitor C4, and finally to the non-inverting input terminal of the second comparator, and the negative pole of the capacitor C4 is grounded. 7 . The intelligent detection circuit of a thyristor dimmer according to claim 6 , wherein the sampling module is composed of a voltage dividing resistor, and the voltage dividing resistor divides the DC bus voltage after the voltage dividing. 8 . The first voltage signal is obtained. 8 . The intelligent detection circuit of a silicon controlled dimmer according to claim 1 , further comprising a digital filter for receiving the digital signal output by the detection module, according to the sudden change of the digital signal. 9 . Whether there is regularity and periodicity to judge and filter out noise, identify whether the thyristor dimmer is connected to the circuit, and output a control signal to control the switch of maintaining current according to the identification result. 9. An LED driving circuit, characterized by comprising the detection circuit according to any one of claims 1-8, wherein the detection circuit is connected to the positive terminal voltage of the rectifier bridge. 10. An intelligent detection method for a silicon controlled dimmer for detecting whether the silicon controlled dimmer is connected to a circuit, characterized in that it comprises the following steps: receiving the DC bus voltage, and generating a first voltage signal representing the magnitude of the DC bus voltage; The first voltage signal and a second voltage signal are respectively connected to the two input terminals of the first comparator and the second comparator, and the second voltage signal is close to the first voltage signal and has a preset value. The phase difference of time, so there is a voltage difference between the first voltage signal and the second voltage signal corresponding to the same time point; An offset voltage is added to the input terminals of the first comparator and the second comparator to compensate for the voltage difference, and the outputs of the first comparator and the second comparator can be adjusted when the thyristor is not detected. The sudden change caused by the light device remains constant, and the opposite potential signal is output when the sudden change caused by the thyristor dimmer is detected.

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