Sine half-wave generating device

Abstract

A sine half-wave generating device comprises a power supply circuit and a test circuit connected with the power supply circuit, a main loop of the test circuit is provided with a connection interface for connection of a test sample, and the test circuit comprises a current peak selection module, a control module, an output module and a waveform direction switching module. The current peak value selection module is used for changing the current peak value on the main loop, and the waveform direction switching module is used for changing the waveform generation direction on the main loop. The beneficial effects of the utility model are that the test circuit is divided into functional modules of current peak value selection, control, output, waveform direction switching and the like, a modularized residual current test system architecture is formed, and sine half-wave pulses which can be flexibly adjusted can be provided according to the performance test requirements of the residual current operated circuit breaker.

Description

Technical Field

[0001] The utility model relates to a signal generating device, in particular to a sine half-wave generating device. Background Art

[0002] Sine half-wave generating devices are widely used in the fields of power electronics and industrial automation. For example, in an AC motor drive system, they are used to generate precise current control signals to adjust the motor speed and torque; in test equipment, they simulate grid fluctuations to verify the stability of inverters or power supplies; and in new energy systems, they serve as reference waveforms for power conversion. During use, the device typically receives an input voltage or digital instruction based on a microcontroller or an application-specific integrated circuit, generates a standard sine wave through a waveform generation algorithm, and then outputs a unidirectional half-wave signal via a half-wave rectifier circuit. The operator presets the frequency and amplitude parameters, but the entire process relies on a fixed hardware configuration and lacks the ability for real-time adjustment, which limits its adaptability in a dynamic load environment.

[0003] However, existing sine half-wave generating devices have significant defects, mainly manifested as the inability to flexibly adjust the current peak and waveform direction. The current peak is fixed and cannot be dynamically increased or decreased according to real-time load requirements, resulting in low efficiency, easy overheating, or equipment damage in variable power applications; at the same time, the waveform direction is irreversible and can only output in a single direction (such as the positive direction), unable to achieve bidirectional control, which severely restricts its deployment in bidirectional energy transfer systems such as regenerative braking or smart grids, and reduces the versatility and performance optimization potential of the device. Summary of the Utility Model

[0004] In view of the deficiencies of the prior art, the utility model provides a sine half-wave generating device capable of adjusting the current peak and waveform square.

[0005] To achieve the above object, the technical solution of the utility model is as follows: A sine half-wave generating device includes a power supply circuit and a test circuit connected to the power supply circuit. A connection interface for connecting a test sample is provided on the main loop of the test circuit. The test circuit includes a current peak selection module, a control module, an output module, and a waveform direction switching module. The current peak selection module is used to change the current peak on the main loop, and the waveform direction switching module is used to change the waveform generation direction on the main loop.

[0006] The beneficial effects of the present utility model are as follows: By dividing the test circuit into functional modules such as current peak selection, control, output, and waveform direction switching, a modular residual current test system architecture is formed, which can provide a flexibly adjustable sine half-wave pulse for the performance test requirements of residual current operated circuit breakers. Each module is independently designed and works in cooperation, which is not only convenient for later maintenance and replacement, but also can be quickly connected to the test sample through a standardized interface. For example, the current peak selection module can cover a wide range of current adjustment from 5 mA to 45 A, and cooperate with the waveform direction switching module to achieve free switching of positive and negative half-waves, meeting the diverse test requirements of different types of circuit breakers for inrush residual current. As a preferred method, the current peak selection module can adopt a multi-stage parallel resistor structure, and the waveform direction switching module can integrate a bidirectional diode switching circuit, and use a mechanical switch to achieve signal direction control at the physical level to ensure stable operation in a high-voltage and high-current environment.

[0007] Further, the current peak selection module includes several resistor circuits respectively connected in parallel to the main circuit, and the several resistor circuits are controlled by the same first switching switch, and the resistance values in each resistor circuit are different.

[0008] By setting multiple groups of parallel differential resistor circuits and using the first switching switch to select branches, different equivalent impedances can be quickly switched on the main circuit, thereby realizing stepped adjustment of the output current peak. This design avoids the range limitation of single resistor adjustment, covers a wider current range through multi-stage combinations, and the resistance value of each stage is independently set, which can meet the grading requirements for current accuracy in the test standard. For example, in a low-current test scenario, the branch containing a high-resistance resistor can be switched to ensure stable output of a micro current of 5 mA level; in a high-current scenario, the low-resistance branch can be switched to support reliable loading of a peak current of 45 A. As a preferred method, each resistor circuit can be composed of a fixed resistor in series with an adjustable potentiometer. The fixed resistor determines the basic resistance value range of this stage, and the potentiometer realizes continuous fine adjustment within this stage. For example, a certain branch uses a 100 Ω fixed resistor in series with a 200 Ω potentiometer. After being connected through the first switching switch, the total resistance of the branch can be adjusted between 100 Ω and 300 Ω through the potentiometer, corresponding to the main circuit current being continuously adjustable within the range of 0.76 A to 2.3 A.

[0009] Further, the resistor circuit includes a resistor with a fixed resistance value and an adjustable resistor that can change its own resistance value, and the resistance value ranges of several resistor circuits cooperate to form an adjustable current peak range on the main circuit.

[0010] Introducing a combined structure of fixed resistors and adjustable resistors into the resistance circuit can achieve a dual adjustment mechanism of "coarse adjustment + fine adjustment" within each gear, ensuring both the range connection between different gears and meeting the accuracy requirements within the same gear. The fixed resistor is used to set the basic impedance range of the gear, while the adjustable resistor realizes real-time resistance value fine-tuning through a knob or a slide rheostat, enabling the resistance value ranges of each resistance circuit to overlap and cooperate with each other, ultimately forming a large-span current peak adjustment range with continuous coverage on the main circuit. For example, the first resistance circuit uses a 500Ω fixed resistor in series with a 1kΩ potentiometer, covering a resistance value range of 500Ω - 1500Ω, corresponding to a current of 460mA - 230mA; the second circuit uses a 100Ω fixed resistor in series with a 200Ω potentiometer, covering a resistance value range of 100Ω - 300Ω, corresponding to a current of 2.3A - 0.76A. The resistance value ranges of the two circuits are connected end to end, jointly expanding the continuity of current adjustment. As a preferred method, the adjustable resistor can be a multi-turn precision potentiometer. By increasing the adjustment stroke, the resolution of resistance value change is improved. Combined with the stepped gear switching of the fixed resistor, the entire current peak selection module can not only meet the precise loading of small currents (such as 5mA) in the circuit breaker test but also achieve the stable output of large currents (such as 45A), avoiding problems such as range discontinuity or insufficient accuracy caused by single-resistor adjustment.

[0011] Furthermore, the output module includes several sampling circuits respectively connected in parallel to the main circuit. The several sampling circuits are controlled by the same second switching switch, and the measurement ranges of the several sampling circuits are consistent with the current peak range on the main circuit; each sampling circuit is connected to an oscilloscope.

[0012] By setting multiple sampling circuits with different measurement ranges and selecting channels by the second switching switch, the signal acquisition accuracy of the output module can be dynamically matched with the current peak range of the main circuit, avoiding small current signals being drowned by the noise of large-range sensors or large current signals exceeding the sensor range. Each group of sampling circuits can be configured with a Hall current sensor corresponding to the range. For example, a 20 - 200mA range sensor is used for the small current gear, and a 5 - 25A range sensor is used for the large current gear. Precise adaptation of "range - gear" is achieved through switch switching. The oscilloscope displays the sampling signal in real time, facilitating the operator to intuitively verify the sine half-wave characteristics and peak parameters of the output waveform. As a preferred method, the sampling circuit can adopt a modular design. Each sensor channel integrates an independent signal conditioning circuit (such as an amplification and filtering module). When the second switching switch switches to a certain sampling circuit, the corresponding signal conditioning parameters (such as the amplification factor) are adjusted synchronously to ensure that current signals of different ranges can be input into the oscilloscope as standard voltage signals (such as 0 - 5V), improving the measurement accuracy and simplifying the debugging process for the operator, and avoiding measurement errors caused by manually adjusting the oscilloscope parameters.

[0013] Furthermore, current sensors with different measurement ranges are connected within each sampling circuit.

[0014] By configuring current sensors with different measurement ranges in the sampling circuit, the full current peak range of the main circuit can be covered in a "division of labor and cooperation" manner, solving the technical problem that a single sensor cannot simultaneously meet the requirements of wide measurement range and high precision. For example, for a current regulation range of 5 mA - 45 A, 5 groups of sensors can be set, covering overlapping ranges such as 20 - 200 mA, 100 - 500 mA, 400 mA - 2 A, 1 - 5 A, and 5 - 25 A respectively. Through the cooperation of the sensor ranges and the shunt resistors, accurate acquisition of the full-range current can be achieved. This design does not require a separate sensor for each resistance circuit, but through the reasonable division and reuse of the sensor ranges, the hardware cost can be reduced while ensuring the measurement accuracy. As a preferred method, Hall closed-loop sensors can be selected as the current sensors, and their magnetic balance principle is used to achieve high linearity measurement. A precision resistor is connected in series at the output end of each sensor to convert the current signal into a voltage signal and then input it into the oscilloscope. When the operator switches the sensor channel through the second switch, the oscilloscope can automatically identify the range coefficient of the current sensor and adjust the display scale to ensure the reading accuracy of the waveform peak and avoid measurement errors caused by manual conversion.

[0015] Furthermore, the waveform direction switching module includes at least two unidirectional energization circuits, and the unidirectional energization circuits are all controlled by the same third rotary switch. Diodes with different conduction directions are arranged in different unidirectional energization circuits.

[0016] Utilizing the unidirectional conduction characteristic of a diode, by means of a third rotating switch to switch diode branches with different conduction directions, it is possible to simply and reliably achieve the switching of the main circuit current direction, and thus control the output waveform to be a positive half-wave or a negative half-wave. The two unidirectional energization circuits respectively correspond to the forward conduction and reverse conduction paths. When the switch is turned to the first gear position, the current flows along the direction of "diode anode → cathode", and a positive half-wave is output; when turned to the second gear position, the current flows in the reverse direction, and a negative half-wave is output. This pure hardware direction switching mechanism does not require a complex phase control circuit and can be achieved only by changing the physical position of the mechanical switch. It has the advantages of fast response speed and strong anti-interference ability, and is suitable for stable operation in high-voltage and high-current environments. As a preferred method, fast-recovery high-voltage diodes can be selected for the diodes, with a withstand voltage value not less than 400V to ensure safe conduction under an AC230V power supply input; the rotating switch adopts a double-throw single-pole structure, and an interlock mechanism is provided inside to prevent the two diode branches from conducting simultaneously. When it is necessary to verify the action characteristics of the circuit breaker for different polarities of residual current, the operator only needs to rotate the switch to complete the switching of the waveform direction. Cooperating with real-time monitoring by an oscilloscope, it is possible to efficiently complete the comparison test of positive and negative half-waves, meeting the diverse detection requirements of type F and type B circuit breakers.

[0017] Further, a first start switch and an indicator light for indicating system startup are provided in the power supply circuit.

[0018] Setting the first start switch and the indicator light in the power supply circuit constructs a safe and reliable system power-on feedback mechanism. The first start switch can adopt a 2P circuit breaker, which has both the functions of power on / off control and overcurrent protection. It automatically disconnects when a short circuit or overload occurs in the circuit to protect internal components; the indicator light selects a high-brightness LED and is connected in parallel with the switch. After the system is powered on, the indicator light lights up, intuitively prompting the operator that the device has entered the standby state. This design not only complies with electrical safety regulations but also facilitates the operator to quickly confirm the device status and avoid performing test operations in an unpowered or faulty state. As a preferred method, a current-limiting resistor can be connected in series in the indicator light circuit to prevent overvoltage from burning out; a locking mechanism can be set for the first start switch to avoid accidental power-off caused by misoperation. For example, after the operator closes the circuit breaker (the first start switch), the LED indicator light (such as red) lights up, indicating that the control circuit and the main power supply have been connected. At this time, the test sample can be safely connected; if the indicator light does not light up, it can be preliminarily judged that there is a problem with the power connection or the switch, and timely troubleshooting is carried out to ensure the safety and reliability of the test process.

[0019] Further, a relay and a time controller are provided in the control module, and the relay and the time controller are respectively connected to a second start switch.

[0020] Through the collaborative work of the control module and the time controller via a relay, precise timing control of sine half-wave pulses is achieved. The time controller can set the pulse width (e.g., 10 ms) and the interval time (e.g., 30 s). The relay (preferably a solid-state relay) realizes zero-crossing triggering conduction of the main circuit according to the signal of the time controller. The second start switch serves as a manual trigger interface. When pressed, it starts the timing of the time controller. When the set pulse width is reached, the relay disconnects, forming a single complete sine half-wave. After the interval time ends, the next pulse output can be triggered by pressing the switch again. This design separates the time logic from the switch execution, supporting both the manual test mode of single triggering and the automated interval pulse output through parameter adjustment of the time controller. As a preferred method, the time controller adopts a digital programmable module, supporting setting the pulse width (adjustable from 10 ms to 100 ms) and the interval time (adjustable from 10 s to 60 s) through buttons or an external serial port. The relay selects a zero-crossing solid-state relay to ensure that conduction and turn-off both occur at the zero-crossing point of the AC power supply, avoiding surge voltages generated by non-zero-crossing switching. For example, when conducting the action characteristic test of a residual current circuit breaker, the operator presses the second start switch. The time controller controls the relay to conduct for 10 ms (corresponding to a complete cycle of a 50 Hz sine half-wave), automatically disconnects after outputting a single half-wave pulse, and can be triggered again after an interval of 30 s, ensuring the repeatability and accuracy of the test data, while avoiding equipment overheating or misoperation of the circuit breaker caused by continuous output. Description of the Drawings

[0021] Figure 1 is the circuit schematic diagram of the test circuit of the embodiment of the present utility model;

[0022] Figure 2 is the circuit schematic diagram of the output module of the embodiment of the present utility model;

[0023] Figure 3 is the circuit schematic diagram of the control module of the embodiment of the present utility model;

[0024] Figure 4 is the circuit schematic diagram of the power supply circuit of the embodiment of the present utility model. Detailed Embodiment

[0025] An embodiment of a sine half-wave generating device of the present utility model is as Figures 1-4As shown in the figure: The device includes a power supply circuit 1 and a test circuit 2 connected to the power supply circuit 1. A connection interface 21 for connecting a test sample is provided on the main circuit 201 of the test circuit 2. The test circuit 2 includes a current peak selection module 22, a control module 23, an output module 24, and a waveform direction switching module 25. The current peak selection module 22 includes six resistance circuits 221 connected in parallel to the main circuit 201 respectively. The six resistance circuits 221 are controlled by the same first switch SA1. Each resistance circuit 221 includes a fixed-value resistor R1-R6 and a variable resistor RP1-RP6 that can change its own resistance value. The resistance value ranges of the six resistance circuits 221 are coordinated to form an adjustable current peak range of 5 mA to 45 A in the main circuit 201. A solid-state relay SSR and a millisecond-level time controller KT1 are provided in the control module 23. The solid-state relay SSR and the time controller KT1 are respectively connected to a second start switch SB2 and SB3. The output module 24 includes five sampling circuits 241 connected in parallel to the main circuit 201 respectively. The five sampling circuits 241 are controlled by the same second switch SA2. Different Hall current sensors JAL12, GHB-05, GHB-2, GHB-5, and GHB-25 with different measurement ranges are connected in each sampling circuit 241. The measurement ranges of the five sampling circuits 241 are consistent with the current peak range of the main circuit 201. Each sampling circuit 241 is connected to an oscilloscope M. The waveform direction switching module 25 includes two unidirectional power-on circuits 251. The two unidirectional power-on circuits 251 are controlled by the same third rotating switch SA3. Diodes D1 and D2 with different conduction directions are provided in different unidirectional power-on circuits 251. A first start switch SB1 and an indicator light DY1 for indicating system startup are provided in the power supply circuit 1.

[0026] The working principle of this device is as follows: Close the first start switch SB1, the power supply circuit 1 is connected, the indicator light DY1 lights up, and the system enters the standby state. Connect the test sample to the connection interface 21. According to the required peak current, select the corresponding resistance circuit 221 through the first conversion switch SA1, and rotate the adjustable resistors RP1 - RP6 for fine adjustment. Select the sampling circuit 241 that matches the current peak range through the second conversion switch SA2 to ensure that the range of the Hall current sensor is suitable. According to the test requirements, switch the unidirectional power-on circuit 251 of the waveform direction switching module 25 through the third rotation switch SA3, select the conduction direction of diode D1 or D2, and determine whether the output waveform is a positive half-wave or a negative half-wave. Press the second start switch SB2, the time controller KT1 starts, sets the sine half-wave pulse duration of 10 ms for output, and at the same time controls the zero-crossing trigger conduction of the solid-state relay SSR. The current in the main circuit 201 forms a loop through the resistance circuit 221, the test sample, and the sampling circuit 241. The Hall current sensor collects the current signal and transmits it to the oscilloscope M to display the waveform. After the pulse output ends, the time controller KT1 automatically times for an interval of 30 seconds. After the interval ends, SB2 can be pressed again to trigger the next pulse. If debugging is required, press the second start switch SB3 to directly conduct the solid-state relay SSR for continuous current output, which is convenient for parameter calibration.

Claims

1. A sine half-wave generating device, comprising a power supply circuit and a test circuit connected to the power supply circuit. A connection interface for connecting a test sample is left on the main loop of the test circuit. It is characterized in that: The test circuit includes a current peak selection module, a control module, an output module, and a waveform direction switching module. The current peak selection module is used to change the current peak on the main circuit, and the waveform direction switching module is used to change the waveform generation direction on the main circuit.

2. The sine half-wave generating device according to claim 1, wherein: The current peak selection module includes several resistor circuits connected in parallel to the main circuit respectively, and the several resistor circuits are controlled by the same first switch. The resistance value in each resistor circuit is different.

3. The sine half-wave generating device according to claim 2, characterized in that: The resistor circuit includes a resistor with a fixed resistance value and a variable resistor that can change its own resistance value. The resistance value ranges of the several resistor circuits cooperate to form an adjustable current peak range on the main circuit.

4. The sine half-wave generating device according to claim 3, wherein: The output module includes several sampling circuits connected in parallel to the main circuit respectively. The several sampling circuits are controlled by the same second switch, and the measurement ranges of the several sampling circuits are consistent with the current peak range on the main circuit; Each sampling circuit is connected to an oscilloscope.

5. The sine half-wave generating device according to claim 3, wherein: Current sensors with different measurement ranges are connected inside each sampling circuit.

6. The sine half-wave generating device according to claim 1, wherein: The waveform direction switching module includes at least two unidirectional power-on circuits. The unidirectional power-on circuits are all controlled by the same third rotary switch, and diodes with different conduction directions are arranged in different unidirectional power-on circuits.

7. The sine half-wave generating device according to claim 1, wherein: A first start switch and an indicator light for indicating system startup are arranged in the power supply circuit.

8. The sine half-wave generating device according to claim 1, wherein: A relay and a time controller are arranged in the control module, and the relay and the time controller are respectively connected to a second start switch.

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