CN1022722C - Low-loss thyristor zero-voltage trigger - Google Patents

Abstract

The present invention relates to a thyristor voltage zero-crossing trigger with low power consumption, which is composed of an autogeny power supply, a voltage zero-crossing detection circuit, a zero-crossing pulse forming circuit, a zero-crossing pulse signal amplifying and triggering drive circuit, and a thyristor, wherein the autogeny power supply and the voltage zero-crossing detector are integrated into one by 4 stabistors which are connected in a bridge mode and alternatively work in the state of reverse breakdown or the state of forward conduction. Only at the moment when the voltage of an electric network crosses zero voltage, transistors of the zero-crossing pulse forming circuit are cut off, transistors of the zero-crossing pulse signal amplifying and triggering drive circuit are turned on, and a narrow negative pulse is output. A majority of the transistors are all in the state of normal-off during both the positive and the negative half periods of the voltage of the electric network.

Description

Low-loss thyristor zero-voltage trigger

The present invention relates to electric and electronic technical field and microelectronics technology, particularly a kind of loss thyristor zero-voltage trigger.

Loss thyristor zero-voltage trigger is one of Primary Component that is used for by high and medium power industrial equipment and laboratory electronic instrument.But mostly existing like product is to influence greatly owing to power consumption the performance index of whole instrument equipment.Such as at D.A.T.A Digest Linear Integrated Circuits Ed.40.1988, enumerated in the product manual in Ed.39.1987.Ed.38.1987 product manual and 691 factories of the Ministry of Aerospace in October, 1988 about silicon control zero-cross trigger parameter, its minimum power consumption index is 200mW(22.5V), if consider on the net by being applied in the 220V single-phase electricity, add the power consumption of authigenic power supply dropping resistor, then total power consumption is up to more than the 5W, domestic disclosed CN-2042257 " silicon control zero-cross triggering power regulating eqiupment " patent, though be single-phase power regulating eqiupment control circuit power consumption can be reduced to less than 0.5W, but still be 2.5 times of whole total power consumption of the present invention.Because the circuit theory of this power regulating eqiupment is employing trigger impulse is arrived the silicon controlled control utmost point by transformer coupled again simultaneously, thereby be not easy to miniaturization, greatly limited the application of device.

The objective of the invention is to avoid the deficiency of above-mentioned prior art, a kind of low-power consumption is provided, be convenient to integration of compactization, can be widely used in the loss thyristor zero-voltage trigger of high and medium power industrial equipment.

The present invention is by self-growing dc power, and voltage zero-cross detects, zero-crossing pulse is shaped: the zero-crossing pulse signal amplifies, triggers drive circuit and controllable silicon formation (as shown in Figure 1).Wherein the two the voltage stabilizing didoe alternation that is connected by four bridge-types of self-growing dc power and voltage zero-crossing detection circuit is at reverse breakdown and the forward conduction state body (as shown in Figure 2) that unites two into one.Promptly four voltage stabilizing didoes are both as the voltage-stabiliser tube of authigenic power supply, again the detector tube that detects as voltage zero-cross.The c of this detection, d two point voltage signals are connected to the transistor base and the emitter of zero-crossing pulse forming circuit respectively by the resistance of two different resistances, zero passage moment at line voltage subtracts each other, and exports a negative burst pulse (as shown in Figure 3) from its collector electrode.So when line voltage is not in zero passage during moment, the T in the zero-crossing pulse forming circuit ₁Pipe is operated in conducting state.The transistor of its collector potential control late-class circuit is in the normal off state; And at the zero passage moment T of line voltage ₁When pipe ends, then by pulse amplitube T ₂The path that diode peripheral with it forms, the negative pulse that pulse former is exported is input to back level amplification, obtains the triggering driving pulse.

Below the structural principle that present invention will be described in detail with reference to the accompanying.

Fig. 1 is a block diagram of the present invention

Fig. 2 is circuit theory diagrams of the present invention

Fig. 3 is an oscillogram of the present invention.

Resistance R among Fig. 2 ₁, R ₂, diode D ₅With voltage stabilizing didoe D ₁, D ₂, D ₃, D ₄Constitute self-growing dc power, simultaneously D ₁, D ₂, D ₃, D ₄Again as zero passage detection.Resistance R ₃, R ₄, R ₅, diode D ₈, D ₉With triode T ₁Constitute the zero-crossing pulse forming circuit.Triode T ₂With peripheral element D ₆, D ₇, R ₆Constitute the zero-crossing pulse signal and amplify triode T ₂And resistance R ₇, R ₈, R ₉Constitute and trigger drive circuit.Voltage stabilizing didoe D ₁, D ₂, D ₃, D ₄Bridge-type connects, and its node a, b are connected to rectifier diode D ₅Negative terminal and an end of line voltage as the voltage-stabiliser tube of spontaneous direct voltage.Node c and node d export as zero passage detection, and its voltage waveform is shown in Fig. 3 b and Fig. 3 c.The c point voltage passes through resistance R ₃Be connected to triode T ₁Base stage, the d point voltage passes through resistance R ₄Be connected to T ₁The emitter of pipe subtracts each other, line voltage zero passage moment from T ₁The collector electrode of pipe is exported a negative pulse, and its waveform is shown in Fig. 3 d.This pulse is by diode D ₆, D ₇Be input to triode T ₂Base stage amplify paraphase, from T ₂The collector electrode output of pipe, its voltage waveform is shown in Fig. 3 e.T ₂The output of pipe is connected to triode T by switch k ₃Base stage, from T ₃The collector electrode output trigger impulse of pipe is through resistance R ₇, R ₈The control controllable silicon.2 of a of bridge diode, b are connected with variable resistor R ₂, to regulate the width of trigger impulse.Capacitor C ₂Be connected T ₁Between pipe collector and the DC power supply, with the interference of filtering line voltage near zero-crossing point influence to trigger.Circuit is worked reliably.Resistance R ₁, R ₂The ON time of scalable trigger impulse circuit and trigger impulse drive circuit, R ₂Also available capacitor C ₃Replace, better with the resistance-capacitance network effect, the dotted portion among Fig. 2 can become one.

The operation principle of this circuit.

C is held in power taking ₁Anodal current potential is with reference to zero potential.

Line voltage is shown in Fig. 3 a, and this voltage is through resistance R ₁, R ₂Step-down, bridge diode D ₁-D ₄Voltage stabilizing, diode D ₅Rectification, C ₁After the filtering at C ₁Two ends produce the direct voltage of a negative approximately 5V, when line voltage greater than V _DThe time (V _DBe D ₁～D ₄Reverse breakdown voltage, be generally about 6V) D ₁, D ₄Reverse breakdown, D ₂, D ₃Forward conduction, the voltage V on the node c _D2=V _J=0.6V(V _JKnot electromotive force for diode), the voltage V on the node d _D4=V _D=6V makes T ₁The pipe conducting, D ₉Also conducting thereupon, T ₁The current potential of pipe collector output is by D ₉Clamper is at V _J=0.6V.D ₆, D ₇, T ₂All not conductings, T ₂The collector electrode output potential of pipe is a capacitor C ₁The negative pole current potential, promptly about-5V.If switch k connects, because of T ₃BE junction voltage on the pipe is about 0, so T ₃Also not conducting, output level are 0.SCR control cathode voltage extremely relatively is 0, does not trigger.When line voltage less than-V _DThe time (negative half period), D ₁, D ₄Forward conduction, D ₁, D ₄Forward conduction, D ₂, D ₃Reverse breakdown.V _D2=-V _J=-0.6V V _D4=-V _D=-6V, T at this moment ₁The pipe conducting.But because T ₃Each electrode potential of pipe is negative value, so D ₉Pipe ends, V _T1C=-1V(T ₁Collector voltage), so D ₆, D ₇, T ₂And T ₃Not conducting of Guan Jun, its operating state is identical with positive half cycle, still is in cut-off state, and output level is 0, does not trigger.

When the line voltage zero passage (be that magnitude of voltage is near 0 value, in this explanation middle finger pact ± 6V, the corresponding time be ± 0.06ms in, we claim to be zero passage moment during this period of time, account for wave period 0.6%) time, D ₁～D ₄The obtainable bias voltage of last institute is not enough so that each pipe enters breakdown conditions, c, d two point voltages all near or equal 0, thereby cause T ₁Pipe ends, T ₂, D ₆, D ₇, D ₉All conductings and constitute path make T ₁The collector voltage V of pipe _TIC≈-2V, T ₂The collector voltage of pipe is near 0V, if connect K switch, then T ₂Manage also conducting, the output negative pulse is added to SCR control and extremely goes up, and triggers the controllable silicon conducting.It is adjustable in 0.12～0.4ms that this triggers pulsewidth.

This shows the diode D that bridge-type connects ₁, D ₄With D ₂, D ₃Alternation makes zero passage detection and authigenic power supply unite two into one at reverse breakdown and forward conduction state, and T in most time ₁The pipe conducting, T ₂, T ₃Pipe ends, only at the zero passage moment T of line voltage ₁When pipe ends, T ₂, T ₃The pipe conducting, thereby at T ₁With T ₂On obtain the burst pulse born respectively.This T ₂, T ₃The ON time of pipe only accounts for the 1.2%-4% of total time.

The present invention is owing to adopted the burst pulse triggering mode of zero passage moment and the merging that most transistor is operated in normal off state and authigenic power supply and voltage zero-crossing detection circuit, thereby power consumption is greatly reduced, its dc power representative value has only 0.7mw, maximum is 1.2mw, the overall power representative value is 120mw under the 220V electrical network, maximum is the summation of 200mw(dc power and AC power dissipation), be tens of/one of existing KJ007, KJ008 circuit; But simultaneously because this trigger zero cross fired under stable state not only, and after power down moment close a floodgate immediately and also can guarantee zero cross fired reliably, thereby eliminated surge, spark phenomenon, prolonged the silicon controlled life-span, and can avoid electromagnetic pollution; In addition since this trigger to have a low consumption low, be convenient to integrated characteristics, thus opened up the application of silicon control zero-cross trigger, particularly particularly extensive in the control of small power electric resistive load.

Claims (1)

1, a kind of silicon control zero-cross trigger comprises zero cross detection circuit, authigenic power supply, and the trigger impulse amplifying circuit triggers drive circuit and controllable silicon, it is characterized in that:

The voltage stabilizing didoe D that a, authigenic power supply and zero cross detection circuit are connected by four bridge-types ₁, D ₂, D ₃, D ₄Constitute, i.e. the bridge-type connected node a of four pipes and rectifier diode D ₅Negative terminal be connected, node b is connected with an end of line voltage, as the voltage-stabiliser tube of authigenic power supply; The bridge-type connected node c of four pipes passes through resistance R ₃Be connected to triode T ₁Base stage, node d passes through resistance R ₄Be connected to triode T ₁Emitter, as the zero passage detection efferent duct, the voltage of c, d two node detection output was subtracted each other in zero passage moment of line voltage, exported a negative pulse from collector electrode, this negative pulse is through amplifying phase-reversing tube T ₂After enter the T of circuits for triggering ₃Pipe, output trigger impulse control controllable silicon;

T in b, the zero-crossing pulse shaping circuit ₁Pipe collector and amplification phase-reversing tube T ₂Anti-phasely between the base stage of pipe be connected with two diode D ₆, D ₇, at the positive half cycle and the negative half period (non-zero passage moment) of line voltage, T ₁Pipe is operated in conducting state, output positive voltage, diode D ₆, D ₇Not conducting, level amplifier tube T thereafter ₂And driving tube T ₃Be in the normal off state, guarantee low-power consumption.

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