Clothing processing zero-crossing detection output module

Abstract

The utility model discloses a kind of clothing processing zero-crossing detection output module, comprising: bridge rectifier;Current-limiting resistor;Zener diode;Current limiting resistor, one end is connected with the clamping node;Optical coupler, input side is connected with the other end of the current limiting resistor, output side is set as emitter follower structure;First pull-up resistor, between the collector of the optical coupler output side and power supply is connected;Pull-down resistor, between the emitter of the optical coupler output side and ground is connected;Triode, its base is connected with the emitter of the optical coupler output side, emitter ground;Second pull-up resistor, between the collector of the triode and power supply is connected, the collector of the triode exports zero point detection signal.This clothing processing zero-crossing detection output module has the characteristics of low power consumption, high safety isolation, strong anti-interference ability and stable detection characteristics.

Description

Technical Field

[0001] This utility model relates to a zero-crossing detection output module for garment processing. Background Technology

[0002] In light industrial equipment such as garment processing equipment, accurate detection of the zero-crossing point of AC mains power is required to achieve precise control of high-power loads such as heating elements and motors. Traditional AC mains zero-point detection solutions mainly include the following types: First, detection is performed after voltage reduction using a transformer, which offers high safety but is bulky and costly; second, detection is performed using a resistor voltage divider, which has a simple structure but high power consumption, typically using voltage divider resistors in the tens of kiloohms range, consuming 1-2W at a 230VAC operating voltage; third, detection is performed using dedicated integrated circuits, but these lack versatility and are difficult to adapt to different working environments.

[0003] These traditional solutions generally suffer from high power consumption, weak anti-interference capabilities, and detection accuracy significantly affected by power grid fluctuations. This is especially true in light industrial environments such as garment processing, where there are numerous devices operating for long periods, resulting in substantial accumulated energy consumption. Furthermore, the zero-point detection window of traditional solutions changes with mains voltage fluctuations, requiring parameter recalibration under different power supply conditions and increasing equipment maintenance complexity. In addition, under strong electromagnetic interference conditions in industrial environments, existing solutions are prone to false triggering, affecting the normal operation of the equipment.

[0004] Therefore, there is an urgent need for a zero-crossing detection output module for garment processing that is low in power consumption, securely isolated, has strong anti-interference capabilities, high detection accuracy, and adaptable to a wide voltage range, so as to provide reliable zero-point synchronization control signals for garment processing equipment and other light industrial equipment. Utility Model Content

[0005] The purpose of this invention is to provide a zero-crossing detection output module for garment processing. This zero-crossing detection output module for garment processing features low power consumption, high security isolation, strong anti-interference capability, and stable detection characteristics.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A zero-crossing detection output module for garment processing includes: a bridge rectifier connected to the AC mains input terminal; a current-limiting resistor, one end of which is connected to the rectified output terminal of the bridge rectifier; a Zener diode, one end of which is connected to the other end of the current-limiting resistor to form a clamping node, and the other end is grounded; a current-limiting resistor, one end of which is connected to the clamping node; an optocoupler, the input side of which is connected to the other end of the current-limiting resistor, and the output side is configured as an emitter follower structure; a first pull-up resistor connected between the collector of the output side of the optocoupler and the power supply; a pull-down resistor connected between the emitter of the output side of the optocoupler and ground; a transistor, the base of which is connected to the emitter of the output side of the optocoupler, and the emitter is grounded; and a second pull-up resistor connected between the collector of the transistor and the power supply, wherein the collector of the transistor outputs a zero-crossing detection signal.

[0007] The present invention is further configured such that the current-limiting resistor has a resistance of 510kΩ, which is used to limit the high-voltage side current within a safe range and provide electrical isolation.

[0008] The present invention is further configured such that the breakdown voltage of the Zener diode is 5.1V, which is used to stabilize the voltage of the clamping node at around 5.1V.

[0009] The present invention is further configured such that the current limiting resistor has a resistance of 1kΩ, which is used to limit the current flowing into the input side of the optocoupler.

[0010] The present invention is further configured such that: the resistance of the first pull-up resistor is 510Ω, the resistance of the pull-down resistor is 10kΩ, and the resistance of the second pull-up resistor is 10kΩ.

[0011] The present invention is further configured such that: the transistor is an NPN transistor, used to convert the output signal of the optocoupler into a standard logic level.

[0012] The present invention is further configured such that the withstand voltage level between the input side and the output side of the optocoupler is not less than 4kV, ensuring electrical isolation between the high voltage side and the low voltage side.

[0013] The present invention is further configured such that the creepage distance and electrical clearance between the high-voltage side and the low-voltage side of the module on the printed circuit board are not less than 6mm.

[0014] The present invention is further configured such that the zero-point detection signal generates a high-level window near the zero-crossing point of the AC mains power, and remains at a low level for the rest of the time.

[0015] The present invention is further configured such that when the high-voltage side of the module operates within the AC mains voltage range of 180-264VAC, the width of the zero-point detection window changes by no more than 10%.

[0016] In summary, this utility model has the following beneficial effects: Low power consumption: This invention uses a 510kΩ high-resistance current-limiting resistor as the core component, controlling the power consumption of the high-voltage side detection circuit to approximately 0.095W, reducing power consumption by about 90% compared to the traditional tens of kilohms voltage divider scheme. This design allows the module to maintain extremely low power consumption even during continuous operation, making it particularly suitable for large-scale deployment in light industrial equipment such as garment processing, effectively reducing standby power consumption. Simultaneously, through Zener diode clamping, the drive current of the optocoupler LED is controlled within the range of 0.3-0.6mA, far lower than the traditional several milliamps to tens of milliamps, further reducing system power consumption.

[0017] High-level safety isolation performance: This invention employs a dual safety isolation system. First, an optocoupler achieves electrical isolation between the high-voltage and low-voltage sides, with a withstand voltage rating of no less than 4kV. Second, the printed circuit board layout strictly maintains a creepage distance and clearance of no less than 6mm between the high-voltage and low-voltage areas, forming physical isolation. This dual isolation structure ensures that the module maintains reliable safety isolation performance even in humid or dusty industrial environments, effectively protecting personnel safety and low-voltage side equipment. Simultaneously, a 510kΩ high-resistance current-limiting resistor also limits the current that may flow to the low-voltage side in fault conditions, providing additional safety assurance.

[0018] Strong anti-interference capability: This invention achieves strong anti-interference capability through the combination of a bridge rectifier, Zener clamp, and a two-stage amplifier circuit. The full-wave rectification and Zener clamp structure makes the detection circuit insensitive to mains power fluctuations, maintaining stable operation within a wide voltage range of 180-264VAC. The low-voltage side uses dual resistors (pull-up and pull-down) to ensure a clear bias state for the transistor under any conditions, avoiding false triggering caused by floating. The two-stage amplifier structure composed of an optocoupler and a transistor improves the signal noise margin, providing a clear zero-point signal even near strong interference sources such as motors and heaters, meeting the reliable operation requirements of garment processing equipment in complex industrial environments.

[0019] Amplitude-adaptive zero-point detection: This invention utilizes Zener clamping to maintain an approximately constant optocoupler LED current under varying mains voltage amplitudes, achieving stability in the width and position of the zero-point window. Within an operating voltage range of 180-264VAC, the width of the zero-point detection window varies by no more than 10%. This characteristic eliminates the need for parameter recalibration under different power supply conditions, significantly reducing the complexity of equipment debugging and maintenance. Furthermore, this stable zero-point detection capability is crucial for processes such as heating control and pressing in garment processing equipment, ensuring the consistency of process parameters.

[0020] EMI / EMC Performance Optimization: The precise zero-point detection signal provided by this invention enables the equipment to switch loads near the mains zero point, significantly reducing electromagnetic interference during switching. Actual measurements show that compared to non-zero-point switching, synchronous zero-point switching can reduce current spikes by 80-90%, significantly reducing harmonic content and minimizing pollution to the power grid and interference to surrounding equipment. This feature not only helps the equipment pass EMC testing but also creates a better electromagnetic environment for the entire factory, improving the overall system reliability. Attached Figure Description

[0021] Figure 1 This is the circuit schematic diagram of this utility model; Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] like Figure 1 As shown, a zero-crossing detection output module for garment processing includes a bridge rectifier (D3), a current-limiting resistor (R55), a Zener diode (D2), a current-limiting resistor (R28), an optocoupler (U5), a first pull-up resistor (R29), a pull-down resistor (R31), a transistor (Q1), and a second pull-up resistor (R30).

[0024] The bridge rectifier (D3) is an MB10F model, connected to the L and N input terminals of the AC mains. The function of the bridge rectifier (D3) is to convert the AC mains power into pulsating DC, making the input polarity insensitive and preventing reverse breakdown during the negative half-cycle that could occur if the LED of the optocoupler (U5) were directly connected to AC. Full-wave rectification also improves the resolution of zero-point sampling, which is beneficial for accurate phase positioning in subsequent control circuits.

[0025] One end of the current-limiting resistor (R55) is connected to the positive terminal of the rectified output of the bridge rectifier (D3), and the other end is connected to the anode of the Zener diode (D2) to form a clamping node. The current-limiting resistor (R55) uses a high resistance of 510kΩ, which is a core innovation of this invention. Connected in series with the mains power, it limits the current entering the detection network, with a peak current of approximately 0.61mA under 230VAC input conditions. Simultaneously, it provides energy isolation between the high-voltage and low-voltage sides, with its voltage drop absorbing most of the mains energy, resulting in a power consumption of approximately 0.095W. A resistor with a power rating of at least 0.25W is selected, ensuring its withstand voltage performance.

[0026] The Zener diode (D2) is model MM1Z5B1, with a breakdown voltage of 5.1V. Its cathode is grounded, and the high-voltage side is the sensing reference ground. The Zener diode (D2) clamps the node voltage at approximately 5.1V, making the current on the LED side of the optocoupler (U5) independent of changes in the mains voltage amplitude, thus ensuring a more constant turn-off window near zero. It also provides a discharge path for the current-limiting resistor (R55), suppressing node drift and induced spikes.

[0027] One end of the current-limiting resistor (R28) is connected to the clamping node, and the other end is connected to the input side of the optocoupler (U5). The current-limiting resistor (R28) has a resistance of 1kΩ and is connected in series with the LED of the optocoupler (U5) for current limiting. When the Zener diode (D2) is turned on, the LED current is approximately 3.9mA (theoretical upper limit). In practice, the current is limited by the supply capacity of the current-limiting resistor (R55), forming a pulse current of 0.3-0.6mA, which is sufficient to trigger the optocoupler with a high CTR (current transfer ratio).

[0028] The optocoupler (U5) uses the FOD817AS model. Its input side receives the current after full-wave rectification and is essentially conductive except near zero. The output side of the optocoupler (U5) employs an emitter follower structure, forming a two-stage amplification structure with the subsequent transistor (Q1), improving its adaptability to small LED currents. The optocoupler (U5) provides creepage / voltage isolation of at least 4kV, achieving safe isolation between high and low voltage levels.

[0029] A creepage distance and electrical clearance of no less than 6 mm are maintained between the high-voltage side and the low-voltage side to form physical isolation. This physical isolation structure, combined with the internal isolation of the optocoupler (U5), constitutes a dual safety protection mechanism, ensuring the module's safety performance in harsh industrial environments.

[0030] The first pull-up resistor (R29) has a resistance of 510Ω and is connected between the collector of the output side of the optocoupler (U5) and the +5V power supply. It pulls the output collector of the optocoupler (U5) to +5V, provides controllable collector current and edge speed, and limits the maximum current flowing into the base of the transistor (Q1) to protect the optocoupler (U5).

[0031] The pull-down resistor (R31) has a resistance of 10kΩ and is connected between the emitter and ground on the output side of the optocoupler (U5). This ensures that the emitter / base returns to zero quickly when the optocoupler (U5) is turned off, preventing the transistor (Q1) from being falsely turned on due to floating. The pull-down resistor (R31) and the first pull-up resistor (R29) form a simple voltage divider / bias network, optimizing the signal switching threshold.

[0032] The transistor (Q1) is an S8050 model, an NPN transistor. Its base is connected to the emitter on the output side of the optocoupler (U5), and the emitter is grounded. The function of the transistor (Q1) is to convert the milliamp-level output of the optocoupler (U5) into a standard TTL / CMOS level signal.

[0033] The second pull-up resistor (R30) has a resistance of 10kΩ and is connected between the collector of transistor (Q1) and the +5V power supply. When pulled high by the second pull-up resistor (R30), the ZERO signal remains at a high level when not driven; when the optocoupler (U5) is turned on, transistor (Q1) saturates, and the ZERO signal is pulled low.

[0034] The working sequence of this utility model is as follows: When the rectified output is far from zero, the LED of the optocoupler (U5) is turned on, and the ZERO output is low. As the mains power approaches zero, the LED current drops insufficient to keep the optocoupler (U5) on, causing it to turn off. Consequently, the transistor (Q1) also turns off, and the ZERO output becomes high. Therefore, the ZERO signal exhibits a high-level window or edge near each zero point. Subsequent control circuits can use the rising or falling edge of this signal to capture the zero-crossing moment, achieving precise zero-point synchronization control.

[0035] This invention utilizes a Zener clamp setting to ensure that the width of the zero-point detection window varies by no more than 10% over a wide voltage range of 180-264VAC. The stable zero-point detection characteristic eliminates the need for parameter recalibration under different power supply conditions, simplifying equipment debugging and maintenance.

[0036] When using this invention, the ZERO signal can be switched at zero point (when electromagnetic interference is minimal) or delayed by a certain angle with a thyristor / SSR (solid-state relay) for phase adjustment. It can also be used for functions such as power grid frequency monitoring and abnormal power outage detection. By using an external interrupt to capture the zero-crossing moment on the rising (or falling) edge of ZERO, precise phase control can be achieved.

[0037] The parameters of this utility model are set as follows: the power consumption of the current limiting resistor (R55) is about 0.095W, and a resistor with a power of not less than 0.25W and a withstand voltage of not less than 250VAC is selected; the peak current of the optocoupler (U5) LED is about 0.60mA (near the peak value of the sine wave); the base current of the transistor (Q1) is about 0.05-0.1mA, and the typical CTR of the optocoupler (U5) is sufficient to meet the requirements.

[0038] In practical applications, the current-limiting resistor (R55) should be a high-voltage thick-film resistor; the Zener diode (D2) should be of low leakage current type with sufficient power consumption margin; sufficient creepage / electrical clearance (≥6mm) should be maintained between the primary and secondary sides when routing the printed circuit board; the ground loop near the optocoupler (U5) and transistor (Q1) should be short; the ZERO signal line should be kept away from the high dv / dt power switching area; if the subsequent microcontroller is a 3.3V system, the second pull-up resistor (R30) can be adjusted to 20k-47kΩ to reduce the pull-down current.

[0039] In summary, this utility model provides a low-power, high-safety, and highly stable zero-crossing detection output module for garment processing. Through the configuration of full-wave rectification + Zener clamping + high-impedance current limiting + optocoupler isolation + two-stage amplification, it achieves precise zero-point detection in light industrial equipment such as garment processing, providing a reliable signal foundation for zero-point synchronous control of the load, while significantly reducing system energy consumption and electromagnetic interference, and improving the safety and reliability of the equipment.

[0040] This utility model provides the following experimental verification of the technical effect of the zero-crossing detection output module for garment processing: 1. A comparative testing method was used to compare the performance of this utility model module with two traditional solutions (resistor voltage divider type and transformer step-down type). The test environment was a standard electronic laboratory (temperature 23±2℃, relative humidity 45±5%). An AC power regulator was used to simulate mains power fluctuations within the range of 180-264VAC, and performance parameters were recorded using an oscilloscope, power analyzer, and EMI testing equipment. The experiment was conducted simultaneously in normal and interference environments (near a 2kW inductive load) to ensure the comprehensiveness and reliability of the test data.

[0041] 2. Technical Effect Comparison Table 3. Verification Methods and Procedures Power Consumption Testing: A precision power analyzer (Yokogawa WT310E) was used to measure the actual power consumption of the three solutions at 180V, 230V, and 264VAC. The resistor divider module consumed 1.45W at 230VAC, the transformer step-down module consumed 0.72W, while the module of this invention consumed only 0.095W. Furthermore, the measured optocoupler LED current was 10-15mA for the traditional solution, while the current of this invention was only 0.3-0.6mA, verifying the low-power characteristics of the weak optocoupler + two-stage amplification approach.

[0042] Zero-point window stability test: Different voltages within the range of 180-264VAC were output from a programmable AC power supply (Chroma 61500), and the high-level window width of the ZERO signal was recorded using a digital storage oscilloscope (Tektronix MDO3000). The window width variation within this range was 42% for the resistor divider type, 25% for the transformer type, while the present invention's module only showed 8%, confirming its constant threshold characteristic with amplitude adaptation. In particular, within the common fluctuation range of 230V ± 10%, the window width variation of the present invention was only 5%.

[0043] Isolation safety testing: The isolation withstand voltage capability of each solution was measured using a withstand voltage tester (GW Instek GPT-9800). The resistive voltage divider type has no isolation or requires additional isolation, the transformer type provides 2-3kV isolation, while this invention combines optocoupler (≥4kV) and PCB placement (≥6mm creepage distance) for dual isolation. Furthermore, the safety performance was further verified through leakage current testing (≤10μA) and insulation resistance testing under high humidity (85%RH) conditions.

[0044] EMI suppression performance test: Three zero-point detection schemes were connected to the same SCR load control circuit (controlling a 2kW electrothermal load), and conducted interference was measured using an EMI receiver (R&S ESR). The peak interference of this module in the 150kHz-30MHz frequency band was 42.1dBμV, which is 34.4dBμV lower than the resistor divider type and 23.2dBμV lower than the transformer type, confirming the EMI suppression effect of zero-point synchronous switching.

[0045] Experimental results demonstrate that this zero-crossing detection output module for garment processing, through its structure of high-impedance current limiting, Zener clamping, weak optocoupler, and two-stage amplification, achieves significant improvements in power consumption, stability, safety, and EMI suppression. In particular, the 87-93% power consumption reduction makes it ideal for large-scale deployment in garment processing equipment, with an estimated annual energy saving of approximately 1200 kWh per 100 units. Simultaneously, its amplitude adaptive characteristic ensures consistent control performance under different power supply conditions, eliminating the need for recalibration and simplifying maintenance. Furthermore, the improved EMI suppression capability helps improve the electromagnetic environment of the factory and enhances the overall system reliability. This invention provides a low-power, high-safety, and highly interference-resistant zero-point detection solution for light industrial equipment such as garment processing, with broad application prospects.

Claims

1. A zero-crossing detection output module for garment processing, characterized in that, include: Bridge rectifier (D3) is connected to the AC mains input terminal; A current-limiting resistor (R55) is connected at one end to the rectified output terminal of the bridge rectifier (D3); A Zener diode (D2) is connected at one end to the other end of the current-limiting resistor (R55) to form a clamping node, and the other end is grounded; A current limiting resistor (R28) is connected at one end to the clamping node; Optocoupler (U5), whose input side is connected to the other end of the current limiting resistor (R28), and whose output side is configured as an emitter follower structure; The first pull-up resistor (R29) is connected between the collector of the optocoupler (U5) and the power supply on the output side; A pull-down resistor (R31) is connected between the emitter and ground on the output side of the optocoupler (U5); The base of the transistor (Q1) is connected to the emitter on the output side of the optocoupler (U5), and the emitter is grounded; The second pull-up resistor (R30) is connected between the collector of the transistor (Q1) and the power supply. The collector of the transistor (Q1) outputs a zero-point detection signal.

2. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The current-limiting resistor (R55) has a resistance of 510kΩ and is used to limit the high-voltage side current within a safe range and provide electrical isolation.

3. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The Zener diode (D2) has a breakdown voltage of 5.1V and is used to stabilize the voltage of the clamping node at around 5.1V.

4. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The current limiting resistor (R28) has a resistance of 1kΩ and is used to limit the current flowing into the input side of the optocoupler (U5).

5. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The first pull-up resistor (R29) has a resistance of 510Ω, the pull-down resistor (R31) has a resistance of 10kΩ, and the second pull-up resistor (R30) has a resistance of 10kΩ.

6. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The transistor (Q1) is an NPN transistor used to convert the output signal of the optocoupler (U5) into a standard logic level.

7. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The withstand voltage rating between the input and output sides of the optocoupler (U5) is not less than 4kV, ensuring electrical isolation between the high-voltage side and the low-voltage side.

8. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The creepage distance and clearance between the high-voltage side and the low-voltage side of the module shall not be less than 6 mm.

9. The garment processing zero-crossing detection output module according to claim 1, characterized in that, The zero-point detection signal generates a high-level window near the zero-crossing point of the AC mains power, and remains at a low level for the rest of the time.

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