CN-116249241-B - Measurement module and LED dimming circuit using same

CN116249241BCN 116249241 BCN116249241 BCN 116249241BCN-116249241-B

Abstract

The application relates to a measuring module and an LED dimming circuit using the same, wherein the measuring module is electrically connected with a PWM signal generating module and a driving device module, the measuring module is used for detecting the channel signals of the PWM signal and the driving device and comprises a measuring processor, a first measuring capacitor and a second measuring capacitor, the first measuring capacitor is arranged at the signal output end of the PWM signal, the signal output end is positioned between electrode plates of the first measuring capacitor, the second measuring capacitor is arranged at the controlled output end of the driving device, the controlled output end is positioned between electrode plates of the second measuring capacitor, the electrode plates with the same polarity are electrically connected, wherein the electrode plates with the positive polarity are electrically connected with the measuring processor and output measuring signals, the electrode plates with the negative polarity are grounded, and the measuring processor receives the measuring signals and compares the measuring signals with built-in reference signals to output measuring results. The application has the effects of reducing the hardware resource requirement and improving the measurement stability.

Inventors

MA RUIJIE
SHI CHUNHUA
LIU JIE
SHI JUNJUN
MA RUIFANG

Assignees

上海穆萨电子科技有限公司

Dates

Publication Date: 20260508
Application Date: 20230217

Claims (9)

1. A measuring module electrically connected with a PWM signal generating module (1) and a driving device module (3), wherein the PWM signal generating module (1) generates a PWM signal, the driving device module (3) responds to the PWM signal to supply power, and the driving device module (3) responds to the generated signal, which is in the same frequency and the same phase as the PWM signal and has different amplitude values, and the measuring module (5) is used for detecting the channel signals of the PWM signal and the driving device; The measuring module (5) comprises a measuring processor (51), a first measuring capacitor (52) and a second measuring capacitor (53), wherein the first measuring capacitor (52) is arranged at a signal output end of the PWM signal, a lead wire of the signal output end is positioned between two electrode plates of the first measuring capacitor (52), the second measuring capacitor (53) is arranged at a controlled output end of the driving device, a lead wire of the controlled output end is positioned between two electrode plates of the second measuring capacitor (53), the first measuring capacitor (52) is electrically connected with electrode plates with the same polarity as the second measuring capacitor (53), wherein the electrode plates with the positive polarity are electrically connected with the measuring processor (51) and output measuring signals, and the electrode plates with the negative polarity are grounded; The first measuring capacitor (52) is electrically connected with electrode plates with the same polarity as the second measuring capacitor (53), and is electrically connected with a detection end of the measuring processor (51), the detection end of the measuring processor (51) indirectly measures current through a resistor, the measuring processor (51) detects the level change times of a measuring signal in one period T of a PWM signal, a reference signal is the level change times or time difference of two adjacent level changes, the measuring processor (51) compares the measuring signal with a built-in reference signal and outputs a measuring result, if the level change times are not up to standard or the time difference is overlong and is not up to standard, the output measuring result is a circuit fault, and otherwise, the output measuring result is a circuit normal.
2. The measuring module according to claim 1, wherein the electrode plates are flat, the leads of the signal output end and the leads of the controlled output end are integrally provided with a drainage plate (6), and the drainage plate (6) is arranged in parallel with the electrode plates.
3. The measuring module according to claim 1, wherein the lead wire is cylindrical, and the electrode plate is arc-shaped and attached to one side of the arc-shaped lead wire.
4. The measuring module according to claim 2, wherein the leads of the signal output end and the leads of the controlled output end are integrally provided with a flow guiding plate (6), and the flow guiding plate (6) is positioned at a gap between adjacent electrode plates.
5. The measuring module according to claim 4, wherein the side edge of the drainage plate (6) is wrapped around the electrode plate electrically connected to the measuring processor (51).
6. The measuring module according to claim 3, wherein an arc-shaped groove is formed in the middle of the electrode plate, and the lead wire is arranged in an arc-shaped hole formed by the adjacent electrode plates and the arc-shaped groove.
7. The measurement module according to claim 1, wherein the measurement processor (51) receives the measurement signal and further comprises: the measuring processor (51) detects the level change times of the measuring signal in the period of the PWM signal, if the level change times are four times, a normal signal is output, and otherwise, an abnormal signal is output.
8. The measurement module of claim 7, wherein the measurement signal is compared with a built-in reference signal, further comprising: if the normal signal is output in the period of the set number continuously, the PWM frequency is increased, otherwise, the PWM frequency is maintained or reduced.
9. An LED dimming circuit is characterized by comprising a PWM signal generation module (1), a signal conversion module (2), a driving device module (3) and an LED module (4) which are electrically connected in sequence, wherein the PWM signal generation module (1) is electrically connected with a measurement module according to any one of claims 1-8, and the measurement module (5) is also electrically connected with the driving device module (3); The PWM signal generating module (1) generates a corresponding PWM signal in response to the received dimming signal, the signal converting module (2) generates a driving signal in response to the PWM signal, the driving signal is in the same frequency and the same phase as the PWM signal and different in amplitude, the driving device module (3) supplies power to the LED module (4) in response to the driving signal, the measuring module (5) detects a channel signal of the PWM signal and the driving device, and compares the difference between the PWM signal and the channel signal to output a measuring result.

Description

Measurement module and LED dimming circuit using same Technical Field The application relates to the field of LED driving, in particular to a measuring module and an LED dimming circuit using the same. Background LEDs are low voltage driven constant current drive devices, and because they are limited by the power level of the LEDs, multiple LEDs are typically driven simultaneously to meet brightness requirements, and therefore, special drive circuits are required to illuminate the LEDs. Different power adapters are required for the LED lamps with different purposes. The existing dimming mode includes PWM dimming, also called pulse width modulation, in which a signal generator repeatedly switches an LED driver using simple digital pulses, and the system simply changes the output current by providing digital pulses having different widths, thereby adjusting the brightness of the LED. The PWM dimming can provide high-quality white light, and is simple in application and high in efficiency. When the PWM dimming is used, in order to detect the parameters of the dimming process, the response states of the PWM and the driving device are required to be measured, so that two measuring branches are required, one measuring branch measures the PWM, the other measuring branch measures the driving device, and then the measuring result of the PWM and the measuring result of the driving device are compared and calculated to obtain the dimming control result. However, this measurement method requires two measurement branches, which occupies more hardware resources. Disclosure of Invention In order to simplify the existing measurement mode and reduce hardware resources occupied by a measurement circuit, the application provides a measurement module and an LED dimming circuit using the measurement module. In a first aspect, the present application provides a measurement module, which adopts the following technical scheme: A measuring module electrically connected with the PWM signal generating module and the driving device module, wherein the PWM signal generating module generates a PWM signal, the driving device module responds to the PWM signal to supply power, the driving device module responds to the generated signal, and the PWM signal is in the same frequency and the same phase and different in amplitude, and the measuring module is used for detecting a passage signal of the PWM signal and the driving device; The measuring module comprises a measuring processor, a first measuring capacitor and a second measuring capacitor, wherein the first measuring capacitor is arranged at a signal output end of the PWM signal, a lead wire of the signal output end is positioned between two electrode plates of the first measuring capacitor, the second measuring capacitor is arranged at a controlled output end of the driving device, a lead wire of the controlled output end is positioned between two electrode plates of the second measuring capacitor, the first measuring capacitor is electrically connected with electrode plates with the same polarity as the second measuring capacitor, the electrode plates with the positive polarity are electrically connected with the measuring processor and output measuring signals, the electrode plates with the negative polarity are grounded, and the measuring processor receives the measuring signals, compares the measuring signals with built-in reference signals and outputs measuring results. By adopting the technical scheme, the two measuring capacitors are adopted as the measuring probes, the two electrode plates of the measuring capacitors are positioned at two sides of the corresponding lead, the change condition of signals on the lead can be sensed, when the lead does not have the signals, the electrode plates can not generate induction signals, when the lead maintains high-level signals, the electrode plates can not generate dynamic induction signals, when the signals on the lead change, the electrode plates can generate dynamic induction signals, so that the measuring processor can detect and compare the signals, finally, the measuring result is output, each measuring capacitor measures the corresponding terminal, after the two capacitors are connected in parallel, the measuring processor can detect whether the corresponding terminal works normally at the same time, so that the hardware resource requirement is reduced, in addition, when the driving force of the PWM signal is reduced, possibly to cause measuring fluctuation, the second measuring capacitor at the controlled output end can transmit the electric quantity generated by the induction of the electrode plates to the first measuring capacitor, the measuring stability is improved, and when the second measuring capacitor inputs electric energy to the first measuring capacitor, the potential of the first measuring capacitor is enabled to be more stable, and the PWM signal driving capability is higher. Preferably, the electrode plates are all