CN87106772A

CN87106772A - The SCR control method and apparatus

Info

Publication number: CN87106772A
Application number: CN87106772.2A
Authority: CN
Inventors: 金恩光
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-03
Filing date: 1987-10-03
Publication date: 1988-06-01
Also published as: CN1009979B

Abstract

A kind of method and apparatus that produces and control SCR trigger pulse, to be transformed to square wave from the sine wave signal of power supply, through repeatedly obtaining each group pulse sequence behind two divided-frequency and the differential, select several above-mentioned pulse trains compound in addition with digital signal, obtain being used to control the silicon controlled trigger impulse.

Description

The present invention relates to the SCR control method and apparatus, particularly relate to numerical control method and corresponding apparatus that controllable silicon triggers.

Existing various SCR control method adopts analog signal control usually or produces trigger impulse, perhaps, digital signal is used further to control or produces trigger impulse behind D/A switch, in U.S. Pat 54435677 and Chinese patent application 85205036, disclose two kinds of silicon controlled voltage regulators.But, up to now, yet there are no digital signal is directly used in the triggering of control silicon controlled, like this, various digital devices, digital computer etc. can't directly be connected with controllable silicon equipment, have in use brought inconvenience.

In addition, relate to concrete triggering mode, usually adopt phase shift triggering or zero cross fired in the prior art, the former disturbs very big to telecommunication equipment, though the latter has many advantages, output voltage distributes in time be not as even as the former.

One of purpose of the present invention is to propose a kind of employing digital signal directly to control the controllable silicon trigger method;

Another object of the present invention is to propose a kind of SCR control equipment that adopts said method.

In the present invention, the silicon controlled triggering mode is a zero cross fired, by producing and the control trigger impulse, makes controllable silicon 360 ° or 180 ° of alternate conduction according to certain rules, produces the output that waveform is composited for several all-waves and half-wave, and this method comprises:

1. obtain the low-voltage ac signal of a same-phase, same frequency from power supply;

2. the waveform to above-mentioned low-voltage ac signal carries out conversion, obtains the corresponding benchmark square wave at zero point of a rising edge and trailing edge and AC signal;

3. rising edge or the trailing edge by the said reference square wave carries out 2,2 to it ², 2 ³... 2 ⁿDivide operation together with the said reference square wave, obtains the square wave of n+1 different frequency altogether;

4. each square wave is carried out differential, produce the pulse signal corresponding with it;

5. select the negative pulse or the positive pulse of several pulse signal accordingly with rising edge in set of number signal and the step 3 or trailing edge;

6. selected negative pulse or positive pulse are carried out the logical "or" computing, obtain being used to trigger the silicon controlled trigger impulse.

In the present invention, trigger impulse and power supply are synchronous, and each trigger impulse is corresponding to the zero crossing of power supply, and therefore, controllable silicon is a zero cross fired, and the angle of flow is at least 180 °, and continuous two trigger impulses can make 360 ° of controllable silicon conductings.Because trigger impulse derives from the different pulse signal in each road, so digital signal also just produced different trigger impulses for the different choice of pulse signal, obtains different voltage thus in load, realized voltage-regulation.

Digital signal can derive from external equipment, as computer and digital instrument etc., perhaps, also can utilize one group of control switch to produce.

Obviously, each step in the said method can utilize existing technological means to realize, the general block diagram of the SCR control equipment that is used to realize said method of having drawn in Fig. 1.Power supply is directly delivered to the voltage changer step-down, by zero-crossing comparator sine or cosine wave are transformed to square wave then, and it is carried out the multichannel frequency division with the multichannel frequency divider, by the multichannel differentiator each square wave is carried out differential again, the pulse signal that obtains is delivered to the logical "or" arithmetic unit after numerical control is selected, carry out exclusive disjunction, produce trigger impulse at last.

This shows, the present invention has realized triggering with the Digital Signals silicon controlled, as a kind of new method, for controllable silicon equipment provides convenience with computer etc. being connected of digital device, and also simple in structure, reduce cost again, owing to adopted zero trigger mode, therefore can not bring public hazards to electrical network, and, in the present invention, the voltage in the load distributes also relatively evenly in time.

Fig. 1 is a general block diagram of the present invention;

Fig. 2 is the block diagram of one embodiment of the present of invention;

Fig. 3 is the line map of over-zero trigger among this embodiment;

Fig. 4 is the line map of seven binary string column split to eight inputs or door among this embodiment;

Fig. 5 is the line map of output amplifier among this embodiment;

Fig. 6, Fig. 6 A to Fig. 6 E are the same width of cloth oscillograms of describing the each point waveform;

Fig. 7 is the connection layout of controllable silicon and load thereof.

In the accompanying drawings, the line end that is shown by identical label all is connected to each other.

Provide an example of the present invention below in conjunction with accompanying drawing.

At first referring to Fig. 2, according to the method that the present invention proposes, the SCR control equipment in this example comprises transformer, zero-crossing comparator, seven binary string column splits, eight derivative networks, eight NAND gate controllers, eight inputs or door and output amplifiers.Voltage changer among Fig. 1 can realize with various devices, for example transformer or resitstance voltage divider, and it and power supply directly link, and export a low-voltage ac signal, keep phase place and frequency constant simultaneously.In this example, adopt a transformer that supply voltage is reduced to about 5 volts and deliver to zero-crossing comparator.

Referring to Fig. 3, the zero-crossing comparator in this example is by operational amplifier G1 and resistance R ₁～R ₉, potentiometer W ₁And capacitor C ₁～C ₄Form.AC signal about 5 volts is delivered to (05), (06) end, behind resistance-capacitance network, deliver to operational amplifier G1, it is general dual operational amplifier F158, the input of two operational amplifiers wherein is respectively 2,3 and 8,6, and each operational amplifier respectively has an

input

3 or 6 respectively through resistance R ₄Or R ₈Ground connection, such as everyone knows, can obtain benchmark square wave at output 7, through current-limiting resistance R corresponding to the zero crossing generation voltage jump of the AC signal of (05), (06) end ₉Output.

Referring to Fig. 4, Fig. 5.Seven binary string column split G2 adopt CC4024, and it carries out two divided-frequency, Q to the benchmark square wave of 1 end input 7 times by its trailing edge ₁～Q ₇Represent respectively the benchmark square wave is carried out each square wave of obtaining behind 1～7 two divided-frequency.These signals together with the benchmark square wave by resistance R ₁₀～R ₁₇And capacitor C ₅～C ₁₂Eight differential nets forming carry out differential eventually, produce a series of and rising edge and the corresponding positive negative pulse stuffing of trailing edge square wave.G3, G4 are two four-2 input Schmidt triggers, with earth resistance R ₁₈～R ₂₅Form eight NAND gate controllers together.

As the secondary technology personnel of this area were known, NAND gate determined output signal jointly by all signals of each input, when input signal is " 1 ", is output as " 0 ", otherwise was output as " 1 ".In this example, as the NAND gate controller is Schmidt trigger, as shown in FIG., one of two inputs supplied with digital signal, another input pulse signal, like this, digital signal just is used as the control signal of NAND gate, when a certain position digital signal is " 1 ", the NAND gate that is added with this digital signal by common NAND gate logical relation as can be known is opened, the pulse signal that is added to the other end of this NAND gate is sent by NAND gate, if when this digital signal be " 0 ", just can't pass through with corresponding pulse signal on this position.Like this, can the level on digital signal is every be just being controlled with these corresponding pulses and passed through respectively for " 1 " or " 0 ", thus, select some row positive pulses, and it is anti-phase in addition, through inverter G5, after G6 is anti-phase once more, in order to obtain required trigger impulse, each row positive pulse is delivered to eight inputs or the door G7 that adopt CC4078 carry out exclusive disjunction, that know according to the medium of this area and elementary skill personnel or logic, its output yes each road positive pulse synthetic is promptly when arbitrary road positive pulse is imported, all export positive pulse signal, and no matter other everybody state how.At last, resistance R in Fig. 5 ₂₆, R ₂₇, transistor T ₁, T ₂And obtain two groups of output signals after the output amplifier amplification of output transformer CB composition, as the silicon controlled trigger impulse.

Referring to the oscillogram of Fig. 6 to Fig. 6 E, the waveform of the each point that drawn among the figure.Another narration method of the course of work recited above is to carry out with reference to oscillogram, is easier to like this understand, even also can understands intuitively the personnel of present technique field known to slightly.

Be the AC signal that obtains after the transformer step-down, it is admitted to over-zero trigger, has just become the benchmark square wave U that rises or descend when its each zero passage _o, U _oSend into serial frequency divider G2 again, so that produce a plurality of pulses to selective use, this serial frequency divider G2 is to U _oCarry out the binary system frequency division seven times, produce one road square wave totally 7 tunnel, i.e. U among the figure at every turn _Q1～U _Q7, together with original hase quasi-retangular wave U _oDeliver to eight derivative networks together and carry out differential, the result is output as pulse signal, as mentioned above, uses digital signal A ₇～A.To U _oAnd U _Q1～U _Q7Select U _A7～U _A0Represent respectively by digital signal A ₇～A.From U _oAnd U _Q1～U _Q7The positive pulse sequence of selecting is chosen when digital signal is " 1 ", otherwise is not chosen.For example, A ₇～A ₀Be 10110101 o'clock, choose U _A7, U _A5, U _A4, U _A2And U _A0, synthesize one road trigger impulse U through eight inputs or door ₁, as shown in FIG., corresponding load waveform such as U _L1Shown in.Equally, A ₇～A ₀Be 01010110 o'clock, the trigger impulse that obtains after synthesizing is U ₂, load waveform such as U _L2Shown in.By seeing among the figure, frequency division is by U.Trailing edge carry out so positive pulse sequence U _A7～U _A0Mutually can not lose some pulse during superposition because of overlapping.When pressing the rising edge frequency division, then select the mutual superposition of negative pulse sequence, just it is passable as long as that this make corresponding changes to circuit, for example, can be negative pulse positive pulse mutually earlier, makes its anti-phase negative pulse that becomes after selecting again.

Drawn among Fig. 7 controllable silicon and load thereof, the identical label of title can see that trigger impulse offers the one-way SCR of two reverse parallel connections respectively among contrast Fig. 5, two controllable silicons can take turns conducting, as common control mode.

Change the size that digital signal can change load voltage, played the pressure regulation effect.The figure place of digital signal can determine as required, when figure place more for a long time, can obtain quite high control precision.

This control appliance also can be used for controlling bidirectional triode thyristor, and this moment is as long as select arbitrarily one group of trigger impulse.

On this control appliance digital display can also be housed, the digital instrument of for example commonly using is with relative value or the absolute value of indication load voltage.

Certainly, can also make all different variations for the present invention, for example, the implementation of each step, the change of line construction, the selections of components and parts etc. obviously also all belong to range of the present invention.

Claims

1, the numerical control method that triggers of a kind of controllable silicon particularly produces and controls the method for trigger impulse, it is characterized in that comprising the following steps:

(1) obtains the low-voltage ac signal of a same-phase, same frequency from power supply;

(2) waveform to above-mentioned low-voltage ac signal carries out conversion, obtains the corresponding benchmark square wave at zero point of a rising edge and trailing edge and AC signal;

(3) rising edge or the trailing edge by the said reference square wave carries out 2,2 to it ², 2 ³..., 2 ⁿDivide operation together with the said reference square wave, obtains the square wave of n+1 different frequency altogether;

(4) each square wave is carried out differential, produce one tunnel pulse signal corresponding with it;

(5) negative pulse or the positive pulse of selecting the several pulse signal accordingly with rising edge in set of number signal and the step (3) or trailing edge;

(6) selected negative pulse or positive pulse are carried out the logical "or" computing, obtain being used to trigger the silicon controlled trigger impulse.

2, a kind of equipment that produces and control SCR trigger pulse is characterized in that comprising:

(1) obtains the voltage changer of low-voltage ac signal from power supply;

(2) above-mentioned low-voltage ac signal is transformed to the zero-crossing comparator of benchmark square wave;

(3) the said reference square wave is carried out the multichannel frequency divider of multichannel frequency division;

(4) each square wave is carried out the multichannel differentiator of differential;

(5) the numerical control selector selected of the pulse signal that obtains after to differential with digital signal;

(6) each the road pulse signal that will select synthesizes the logical "or" arithmetic unit of trigger impulse.

3, equipment as claimed in claim 2 is characterized in that, further comprises an output amplifier that trigger impulse is amplified.

4, as claim 2 or 3 described equipment, it is characterized in that, further comprise the digital display of the value that is used to show load voltage.