CN2812404Y - A device for acquiring zero-cross synchronization signal of controllable silicon - Google Patents

Abstract

The utility model discloses a device for acquiring zero-crossing synchronization signals of a thyristor, which comprises one circuit of half wave trapezoid shaping circuit and an SCM system. The utility model is characterized in that the device for acquiring zero-crossing synchronization signals of a thyristor also comprises another circuit of half wave trapezoid shaping circuit, and a positive and negative half wave shaping circuit for input sine-wave voltage is formed by the two circuits of half wave trapezoid shaping circuits. The SCM system can carry out operational analysis on the rise edge and the fall edge of input positive and negative trapezoidal wave, and obtains waveform width and the center point of the waveform generated between the rise and the fall. A circuit which obtains corresponding square wave through utilizing and shaping the rise and the fall of the positive and the negative trapezoids output by the trapezoid shaping circuits can also be arranged between the positive and the negative trapezoid shaping circuits and the SCM system. The rise and the fall edges of the positive and the negative trapezoidal wave generate a wave center point, that is a triggering point of zero-crossing synchronization signals of a thyristor, and the triggering point can make the thyristor reliably triggered at a zero-crossing point. The thyristor is prevented from the impact of instantaneous electric rush current when the thyristor is switched on. The thyristor and the load thereof are effectively protected. In particular, capacitive load extends the service life of the thyristor and saves cost for users.

Description

A kind of device that obtains the silicon control zero-cross synchronizing signal

Technical field

The utility model relates to the device that a kind of automatically controlled signal obtains, and especially obtains the device of silicon control zero-cross synchronizing signal.

Background method

Controllable silicon also is thyristor, and its architecture is simple, and control is convenient, and price is not high yet.As long as add correspondent voltage, in control extremely, apply the conducting triggering signal again, but just conducting between the both positive and negative polarity there is electric current to flow at its both positive and negative polarity.Particularly bidirectional triode thyristor is as long as have the conducting triggering signal in the control extremely, and two interpolars use easily reliable with regard to conducting.In alternating current circuit, be commonly used for the noncontacting switch of power supply and circuit, bringing onto load.Be applied under the situation of capacity load, when asynchronous with triggering signal as if the alternating current that is applied to controllable silicon two positive and negative electrodes, because power supply is applied to the moment on the capacity load, if overtension, can cause the combined floodgate surge stream of moment and controllable silicon is damaged, also can cause rush of current seedling and equipment to capacity load, cause economic loss.This is the common recognition on this technical field.For this reason, the related personnel in this field after deliberation and the practice, think the controllable silicon two ends in voltage zero-cross, the triggering and conducting controllable silicon is a best choice, to the injury minimum of controllable silicon and capacitive load.

At present, the method that the silicon control zero-cross synchronizing signal obtains normally adopts halfwave rectifier, is defeated by single-chip microcomputer with half waveform after shaping and handles, and exports triggering signal to the silicon controlled trigger electrode by single-chip microcomputer then, makes controllable silicon in the conducting of zero passage place as far as possible.This method is for input voltage when higher, more than 220V, the zero passage synchronous triggering signal just relatively accurately, if when input voltage is low, below 50V, departing from of zero passage synchronous triggering signal is just big.This mainly is because the nonlinear characteristic that half-wave rectifying circuit occurs when voltage is low determines.Obviously adaptability is bad, and, the voltage height of control circuit, withstand voltage corresponding also needs of components and parts improves, and cost is also high, and reliability reduces relatively.

The utility model content

The purpose of this utility model provides a kind of silicon control zero-cross synchronous signal device that obtains, and can solve the precision problem of silicon control zero-cross synchronous triggering, and, haveing nothing to do with the high or low of input voltage, the impact of surge is avoided in protection controllable silicon and load thereof.

The utility model comprises one road half-wave ladder shaping circuit and Single Chip Microcomputer (SCM) system, it is characterized in that also comprising:

Another road half-wave ladder shaping circuit, two-way half-wave ladder shaping circuit constitutes the positive and negative half-wave shaping circuit to input sine wave voltage.

Described Single Chip Microcomputer (SCM) system can be carried out operational analysis to positive and negative trapezoidal wave rising edge and the trailing edge of being imported, and obtains waveform width and the mid point thereof of producing between described rising and the decline.

Between described positive and negative ladder shaping circuit and Single Chip Microcomputer (SCM) system, also can be provided with the positive and negative trapezoidal rising that utilizes two ladder shaping circuits output and descend and obtain the circuit of corresponding square wave through shaping.

The device of said structure; be the trigger point of silicon control zero-cross synchronizing signal by the mid point of two positive and negative trapezoidal wave rising and falling edges generation waveforms; this trigger point can make controllable silicon reliably trigger at the zero crossing place; avoided the impact of the combined floodgate surge stream of conducting moment; protect controllable silicon and load thereof, particularly capacity load effectively, prolonged their useful life; for the user has saved cost, increase economic efficiency.

Description of drawings

Fig. 1 is circuit theory diagrams of the present utility model.

Fig. 2 is the voltage oscillogram of respective points among Fig. 1.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail.

In the utility model circuit theory diagrams shown in Figure 1 as can be known, by two zero passage optical coupler V ₁And V ₂Respectively with corresponding resistance R ₁, R ₃And R ₂, R ₄Constitute positive and negative two-way half-wave ladder shaping circuit.Wherein, take from bidirectional triode thyristor K _pThe circuit input end of two end electrodes L, A passes through resistance R respectively ₁, R ₂With two optical coupler V ₁, V ₂Anodal connection of input, also intersect respectively and be connected with the input negative pole of two optical couplers.Resistance R ₃, R ₄One termination power+V _c, the other end meets two optical coupler V respectively ₁, V ₂Output, the voltage of these two outputs is respectively U _xAnd U _yTwo zero passage optical coupler V ₁And V ₂Two output voltage U _xAnd U _yAll be input to AND circuit G, the output voltage of this AND circuit G is U _GInput signal as Single Chip Microcomputer (SCM) system.The output of Single Chip Microcomputer (SCM) system and controllable silicon K _pThe control utmost point connect.The end of capacity load C is connected with silicon controlled one electrode A, another termination public zero curve N.

Shown in Figure 2, be the voltage oscillogram of each respective point among Fig. 1.Among the figure, controllable silicon K is arranged _PBoth end voltage U _LA, zero passage optical coupler V ₁And V ₂Output voltage U _x, U _y, and AND circuit G output voltage U _GOscillogram.In conjunction with Fig. 1, the input voltage U of Fig. 1 _LABe sine wave, positive half wave is through the first zero passage optical coupler V ₁The back draws voltage U at output _x, it is recessed trapezoidal that its waveform should be mutually; Negative half-wave is through the second zero passage optical coupler V ₂The back draws voltage U at output _y, its waveform is recessed trapezoidal, but direction with voltage U _xStagger close opposite.The voltage U of two trapezoidal waves _xAnd U _yThrough AND circuit G, voltage U _xRising edge and voltage U _yTrailing edge make AND circuit G output voltage U _G, this voltage U _GWaveform be square wave.By being clear that square-wave voltage U among the figure _GMid point be sine voltage U _LAZero crossing.This square-wave voltage U _GBe input in the Single Chip Microcomputer (SCM) system, the width of this square wave is obtained in computing by analysis, gets its mid point and signals as the contact, triggers controllable silicon K _PThe control utmost point, make controllable silicon K _PIn zero passage place triggering and conducting, its error is very little.This trigger point signal obtain and be applied to controllable silicon K _PBoth end voltage U _LAHeight irrelevant, this can obviously debate out from the oscillogram of Fig. 2.At controllable silicon K _PThe voltage over zero place triggers, and makes controllable silicon K _PAnd load, particularly capacity load, avoided the impact of combined floodgate surge stream, improved controllable silicon K _PWith the reliability and the useful life of load.

In SCR control principle and practice, we also recognize, in Fig. 1, do not adopt AND circuit G, with the voltage U of two trapezoidal waves _xAnd U _yBe directly inputted in the Single Chip Microcomputer (SCM) system, utilize the rising edge of these two voltages and trailing edge to analyze computing, obtain the waveform width that produces between the corresponding rising and falling edges, getting its mid point more also is feasible as triggering signal, also can reach at controllable silicon K _PThe effect that voltage triggers at the zero passage place is though it is complicated to do the structure and the program that can make Single Chip Microcomputer (SCM) system like this.But this also is to make controllable silicon K _PRealize an approach of zero passage synchronous triggering, also can adopt.

Claims (2)

1, a kind of device that obtains the silicon control zero-cross synchronizing signal, it comprises one road half-wave ladder shaping circuit and Single Chip Microcomputer (SCM) system, it is characterized in that also comprising:

Another road half-wave ladder shaping circuit, two-way half-wave ladder shaping circuit constitutes the positive and negative half-wave shaping circuit to input sine wave voltage.

2, a kind of device that obtains the silicon control zero-cross synchronizing signal according to claim 1 is characterized in that:

Between described positive and negative ladder shaping circuit and Single Chip Microcomputer (SCM) system, also can be provided with the AND circuit (G) of shaping output square wave.

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