DE1638958A1 - Circuit with controllable rectifiers - Google Patents

Description

DR. E. WIEGAND DIPL-ING. W. NIEMANN 1638 958

DR. M. KÖHLER DIPL-ING. C. GERNHARDT

Munich Hamburg

phone: 395 314 2000 HAMBURG 50, Oct. 20, 1967

TELEGRAMS = KARPATENT KDNIGSTRASSE 28

W. 22 984/67 4 / F

Westinghöuse Brake and Signal Company Limited London (England)

Circuit with controllable rectifiers.

The invention relates to circuits with controllable Rectifiers and in particular to means for generating trigger pulses for a controllable rectifier in such a circuit.

According to the invention is a circuit with controllable Rectifiers created, which contains means which on address the voltage on a path designed to a controllable rectifier for charging a storage device and also a holding device contains, which responds when working to an applied control signal to the memory device with the trigger input point of the controllable rectifier and no transfer of energy from the storage device to enable the rectifier / to initiate the conduction of the controllable rectifier.

The storage device can, for example, have a capacity or have a secondary storage cell.

.108 * 32 / 0.26 * '

- 2 -... ■: - "■■■■■ ■. ■;"

Means can be provided which "ensure" that the transfer of energy via the switching device can only occur when a predetermined value of the voltage is present on the storage device, and this can be achieved by arranging a Zener diode in a current path via a switching device between the storage device and a expensive signal input s te, ll of the switching device. ^ are effected. ■ - · - ..
The invention is explained below in conjunction with the drawings using exemplary embodiments, to which, however, the invention is not limited.

Fig. 1 shows part of a controllable "equal * -"

"riehter containing circuit, according to. . the invention. - / - ■. ■ "■."

FIG. 2 illustrates in graphical form the operation of the circuit according to FIG. 1. Fig. 3 shows a modified embodiment of the

Circuit according to-Fig. 1.

. Fig. 4 shows a .other modified embodiment \ • shape of the circuit according to Fig. 1. · ■ = Fig. 5 illustrates the application of the invention with a circuit design, polygamy more - as a controllable rectifier contains "■". ". however the use of a single memory · *

device allows. ^ä \ -. _; -

6 shows a circuit according to the invention,

109832/0 265

one switching device from another

Contains shape. '
Figures T and 8 show modified embodiments

of the basic current circuit according to FIG. 1 again. In Fig. 1, a controllable semiconductor equalizer 1 is shown, which is assumed to be connected in a current path between an alternating current supply source and a load. A series path is connected in parallel to the controllable rectifier 1 and consists of a resistor 2, a capacitor 3, a diode 4 and a capacitor 5, the connection point between the diode 4 and the capacitor 5 being the one via a further controllable semiconductor rectifier Represents switching device, and a resistor 8 is connected to the control electrode of the controllable rectifier 1. Furthermore, the

and/ "

Diode 4 to the capacitor 5 lying in series with it Zener diode 9 connected in parallel. The control electrode of the Switching device 6 is connected to terminal 10 of the positive control input via a resistor T, and terminal 11 of the negative control input is connected to the cathode the switching device 6 connected.

Typical values for capacitors 3 and 5 are

/ or 2 IiF. As a result, if it is assumed that the avalanche breakdown voltage of the diode 9 is about 20 volts is, by a positive increase of 100 volts at the anode of the controllable rectifier 1 of the capacitor 5 on

■ - ■■■ ■ BAD pBJSINAL

109832/0765 ^

charged a voltage of about 20 volts, and a further increase in the anode voltage of the rectifier 1 results no further increase in the voltage on the capacitor 5 as a result of the subsequent conduction of the diode 9 in the avalanche state.

_If, therefore, the working of the circuit according to Pig, 1 is considered and it is assumed that an alternating current supply voltage of about 300 volts is present during a positive half cycle of an alternating current operating waveform applied to the rectifier 1, then a charging current flows through the Parts 2, ~ 5, 4 and -5, which charges the "capacitor 5 to a value of about 20 volts within a short initial period of the half-cycle, and the subsequent application of a control signal with the polarities shown to the terminals 10 and 11 calls for conduction the switching device 6 out to the discharge of the capacitor 5 ^a l "S an applied to the control electrode of the rectifier 1

initiate w th impulse. Assuming that the resistor 8 has a comparatively low value, the pulse applied to the control electrode of the rectifier 1 is a high-amplitude pulse and the rectifier 1 is made conductive. The moment at which a control signal is applied to the connections 10 and 11 can be selected as desired

". , in order to change the ignition angle of the rectifier 1, however, it must be taken into account that the switching device 6 should only be made conductive if one is sufficient

109832 / 026S

. 1138058

high 'voltage' is reached on the capacitor 5 wooden ..

Compared to other forms of triggers, the illustrated Sfcrornkreisfilliiung has the Fppleil / that the Zener diode 9 with a) Irapul.S with Japanese atnplitiUde and a rapid rise, what, the most favorable conditions for resistance high ??; The rate of rise of the anode current. in the unstable oil eie ^ ricijtep i without the additional energy equilibrium ^{; .el3-;} ©? L · .higher leisfciang liiGh, I can furthermore, ^ enn eirie 2we, Gkentspi »e0 |} end SG] riLaltöiV2? Direction; ung β as a given assumption wipd _f one digen4e. ^s Ä ^ fe.eilen mit Steuepsieijalen with niedpigep Ampl, er.peißht be ^ y / el-ßhe keijig ^ bescindeFS need to have .. Therefore, the Grgfe ^ the Ko.gte & ur the energy requirement of the Inepgieau'elle the adorns v / earth, and the problems go; lip | i Ygn gteu ^ PiwPHlse ^ j Phne itipe tyel] Lenf @ ¥ ß z \ x while at the same time an ISGlatipli i ^ d mp; gi.ieherw@i.se gine IioGhspannungsisolafcion Gesöhaffen ". ^ iPd ;, can also be significantly reduced, ■..

In 4 graphical representation of the Ftg. " ? - the waveform A gives the alternating current supply voltagej the variety. the V / ellenform D the 3 voltage occurring at the capacitor 5 and 4ie VJellenforin I the gate current, in the controllable rectifier \ again,:

1038958

D 9

With reference to FIG. 2 it should be remembered that connection is carried out with the circuit design according to Pig, I; mvdg, if it is not desirable to switch the holding device β on in the absence of sufficient voltage, the *. Capacitor §, to trigger. With the circuit; according to Fig * J? where in addition a transistor 14 and one with it? Zenerdiocie 15 lying in the row are provided

k achieved this goal in that the Zener diode 15 rmr in the *> -

ψ ":" ■■ '■■■'. ■■

Would i§fc _# the necessary current: to conduct in order to switch

yor »riahfcyi} g ß conductive to maahen, v / enn gusäfczlieh to open the transistor ik dig I, awinen @ pannu.ng the Zenerdioäe Ig überepsetoit ^ en. In other respects he works. It was similar to Fig. 5 3-ffl essentially as well as the current according to Fig. I. _:. , / ■■ ..

The _r circuit according to the invention shows if one

al? Storage device is used, the broader principle that the capital is used as a sub-system and tension component in a complete circuit? What can be done in order to limit single swing (transient) voltages at Mn be ^ pgffend © n controllable aieichrioiitgrn and vfafe ternin the type speed of the anode chip

There can be different arrangements fosw, designs yon pio, 4en and Wtciirsfcänaen in connection with the capacity

tive storage device can be used; in order to obtain different characteristics with respect to the transient and 4τ · suppression in the circuit. For example, in the current circuit design "according to FIG. 6 , -in which the zener diode y is connected directly via the capacitor"5; , Fe und'eine further diode IJ _s is added to the capacitors 5 and 5 connected -rr irn view of a * of positive value directly to the controllable Hauptgreichrichfcer 1, except · is .the j5 capacitor with the resistor. 12 in. Row, with a view to the discharge currents> which from the capacitor 5 via the controllable rectifier 1. go when the latter has been made conductive. Therefore a high capacitance value can be used for the capacitors 3 and 5 in order to obtain an effective suppression and voltage division when the controllable rectifier is used in conjunction with other controllable rectifiers in a current circuit without the controllable rectifiers are damaged as a result of an excessive peak current flowing from the corresponding capacitor, eg the capacitor 3 * when the relevant controllable ■ rectifier is triggered .. ■ · ■ .- ■ ·

In Fig. 5-is a controllable full-wave rectifier bridge arrangement illustrated in which the invention. is applied. The bridge circuit contains controllable rectifiers 1 and la and, SiQden 20 and 20 a, and the connection points between the Di ^ dg.20 and the rectifier 1 resp.

BAD ORFGlMAL

between, the diode 20 a and the rectifier "1 a are with Input connectors 20 and 2 ^ connected to an AC power source connected. The junction between the 20 and 20 a is with one terminal of the Load 24 connected, and the junction-between the Rectifiers 1 and 1 a is connected to the other terminal of the load 24.

Let us now consider the part of the circuit which contains the controllable rectifier 1. A series circuit of a resistor 2,, · a capacitor J :, a diode 4 and a capacitor 5 is connected in parallel to the rectifier ■ I -. The Zener diode 9 is connected via the capacitor 5, and since the reverse path via the Zener diode 9 is now separated from the capacitor 5 by the diode 4, a further diode 21 is connected in parallel with the diode 4 and the capacitor 5 in series with it . The capacitor "5 is _again; a switching device β in the form of a controllable rectifier to the trigger electrode of the rectifier 1 via a resistor 8 is connected the gate electrode of the switching device 6 is further connected via a resistor 7 to the input control terminal 10 and the input control terminal 11 is. connected to the cathode of the switching device 6.

That part of the circuit that is the second controllable Rectifier 1 a contains, is like the circuit part, which contains the controllable rectifier 1, and the ent-

■: ■ '■' :. _ ₉ _ ■] 1838958

speaking components are provided with the index a; it can be seen that the capacitor 5 and the Zener diode 9 are common to both parts of the circuit.

When working the circuit design according to Pig * 5, at the beginning of a positive half-cycle of the supply waveform that occurs at terminal 22, a current flows through the series connection of parts 2, 5 K and 5 ^: until a point is reached at which the Switching diode 9 reaches an avalanche breakdown state, and the voltage on capacitor 5 is then held at this value. The subsequent application of a control signal to the trigger electrode of switching device 6 enables a discharge pulse to flow through device 6 to make rectifier I conductive to ^trigger; -

The subsequent reversal of polarity of the supply waveform erases the rectifier 1, and passes the re-charging of the capacitor 5 via the path resistor 2a, the capacitor 35a, the diode a 4 and the capacitor 5 includes ^a, back to a point a, at which the Zener diode 9 reaches the avalanche breakdown state. The subsequent application of a control signal to the trigger electrode of the switching device 6a makes it conductive * in order to apply a trigger pulse to the controllable rectifier 1a, which then remains conductive until the end of the relevant half-cycle. A controlled full-wave rectification of the alternating current waveform is thereby achieved, and the on

109832/0265

the load 24 applied voltage "can be changed by changing the angle at which the control signals are sent to the Input connections 10, 11 or 10a, 11a are applied during the relevant half-periods of the feed waveform, is advanced or decelerated.

The circuit according to FIG. 6 again contains a single one controllable rectifier 1, however, the previously of 'A controllable rectifier formed switching device 6 replaced by a triggerable diode 16 / and in this Case 1st to provide an absorption to ports 10 and 11 applied control signals through the capacitor 5 to '.. prevent another diode 17 in the connection of the An » Connection 10 with the junction between the diode 4 and the capacitor 5-connected. The operation of the circuit according to FIG. 6 is then essentially the same as that of the circuit according to FIG. 1, but it can be seen that this embodiment has the advantage under certain circumstances has that when the triggerable diode 16 is conductive, a direct connection from the control input port to the ■ Gate electrode of the controllable main rectifier 1 is present, therefore the gate drive to the rectifier X-one from the capacitor 5 starting pulse higher Amplitude, followed by a pulse of lower amplitude but longer duration. Can have a somewhat similar effect if desired with the circuit design according to Fig. I if the negative control terminal, instead

■ ■■ ) i> yh ^% i £ ^ iM &'^: \ -' '' ■■. '. ■■■■■■' ■■■■ "■

- 11 - - ■ ■.

as shown, with the cathode of the controllable rectifier 1 connected. Is. Such a circuit is in Fig. 7 shown.

It is. can be seen., d, aß the circuit according to FIG. 7 basically corresponds to that of FIG. 1, with the Exception that the trigger input terminal 11 with the cathode of the controllable semiconductor rectifier Γ connected is. The trigger input connection 10 is with the gate electrode of the controllable rectifier 6 via a Dio <de 26 and continue to the cathode of the rectifier β via the. Diode 26 and another resistor 27 connected. Of the Terminal 10 is. also via a further diode 28 with connected to the anode of the rectifier 6.

As long as aas applied to connections 10 and 11 DC control signal is sufficient as such, the To trigger controllable rectifier 1, this arrangement can guarantee a satisfactory operation of the circuit under all conditions, because if the thyristor anode voltage is strongly positive when the trigger pulse is on the terminals 10 and 11 is applied, the full amplitude of the gate control pulse is obtained. But if it is should happen that the control pulse is applied before the anode of the rectifier 1 becomes positive * has the gate current has already reached a sufficient level if it subsequently does it.

One possible cause of the

10 98 3 7/0265

- 12 - - ■■■■■. ■ -.... . ■ .:

Circuit results from the consideration that there is a direct supply from the positive terminal IC via the diode 26, the gate-cathode circuit = the device 6 and the resistor 8 to the trigger electrode αes rectifier 1, and in aer abnormally sensitive controllable rectifier * at the point of the rectifier 1 at the edge triggered * before the device 6 becomes conductive. ^: Direction 6 can be used, which has a high switching speed, the possibility of this wrong Arbelt ens occurring in practice is so remote that it is negligible. It is therefore possible to use this circuit without any significant consideration of the rise time of the. Pulse ... which is applied to terminals 10 and U ".. .. ■ ■ -. - - ..:.

In the previous paragraph it was indicated that ¹ the - t circuit design, as shown in Fig. 7,

is generally applicable under all conditions, however , this does not include conditions where the receipt a pulsing input isfc to connections 10 and 11, .vile it with certain forms of drive circuits of the Is the case in which blocking oscillators are used to provide the trigger pulse. There is etoe .. basic limitation in connection with a pulsating drive · at connections 10 .and 11 ,. which theirs

The reason for the use of a controllable semiconductor device for the switching device 6. Bi it arises from the? Consideration that if the first attempt to trigger the controllable main alignment device 1 should not be successful, the switching device 6 seeks to keep itself in its conductive state via the capacitor 2, 'if that Anodertpotential of the controllable main rectifier 1 continues to rise, -. "". "" ■■ " ^Λ

. If so: the control input applied to connections 10 and II is a train of short pulses, then you can see them Situation arise that after the first possibly ineffective pulse * which is derived from the capacitor 5, the main rectifier only received short pulses from the input terminals 10 and 11 receives with the charge current of capacitor j5 between them. In a case in which the anode potential of the main thyristor rises sharply, and on this rise a low current towards zero follows, as may be the case when "the circuit: in an AC regulator with an inductive load is used, it is quite possible that the somewhat indeterminate Trigger status leads to unsatisfactory triggering of the controllable rectifier 1 with its subsequent damage leads.

The difficulty mentioned in the previous paragraph in connection with an applied to the ports 10 and 11 pulsating drive was indicated, this can lead to

109832/026

16S8SS8

be avoided / that a .abgevmndeϊtέ - ". ΐ'o ■ rϊn '"' of the ■ "■"'3 ■ fer · oπü £ ί * ^ ise & i ■, for example, the one shown in' Fig.:- "8 is used .., In DENR circuit shown in FIG 8 is the Steuereingangsa * i - \ circuit 11 ß again | it the cathode of the controllable ^Haiblei-: tergleichrichters I connected, However, the input terminal Io via resistors 29 and 30 with the bath of a transistor > 1 connected, which is connected via the ^: SchaltVorrichtungf 6: ':> , with which a diode j? 2 in series;

; is; 'The input connection 1' is still via a ^; iiiderstand / 35 and eine'Diode 28 * which the diode "28 of ^the:;. FIG. 7 enitspricht, ϊ angesehlos- to the collector of the transistor 3>; sen The drives to the trigger electrode of the Vorrichtürig '6 is of the ¥ genetic manure' steep of the resistors 29 and J0- ^: abgenomineifi via a capacitor 55, and the trigger electrode- _: the switching device 6 is connected to its cathode via a resistor 3 &

In the operation of the circuit according to FIG. 8, the operates Circuit containing capacitors 3 and 5 and the zener. Diode 9 contains, as explained above, a relatively strong trigger pulse for the Sehaltvorrichtung 6 to deliver the rectifier 1. However, to the fact too take into account that the input at terminals 10 and., ...; 11 a pulsating input can be, the = = bridges Transistor 31 during the course of each drive pulse the switching device 6 so that it can .rückstellen itself after each pulse in its blocking state, so that

109832/026

163895S

- 15 - ■ ■: -

weim; the anode potential of the rectifier 1 further an- · stedst> rder capacitor 5 is at least in _; to a certain extent again - .. can recharge before the next pulse: is applied. - "■ -.-. ·; ■ -.. _: · ■ - · ■ ·.-.- ■ - '-...." - ".- ■

Der.Triggerimpuls for the switching device 6.wird ^ applied across the capacitor -35 so that the device ^. ^ Not until the end of the trigger pulse, through which the gate current is stopped, and the capacitor 55 is used / continues. the purpose of: to delay the base drive to transistor ^ l to ensure; that .the ^: transistor 3I.not, through. . an excessively high collector current is damaged, but-. which begins to conduct only when the capacitor 5 '-' has been discharged to a large extent. When the transistor 51 conducts, the current passing through the resistor 33 is combined with any residual current coming from the. Capacitors J and 5 pass through resistor 8.,. diverted away from the switching device 6, which switches on in a time period of, for example, 10 to 20 microseconds. The shutdown process is supported by the additional voltage drop that occurs at the above-mentioned • additional ..

----._ "■ ■■ - ■ _- ■ i ■

Diode 52 generates xvird. _;

If, therefore, in the circuit according to FIG. 8, the controllable Semiconductor rectifier 1 from a special drive pulse that is applied to terminals 10 and 11 * not is triggered into the conductive state, the charge absorbed by the capacitor 5 at the point in time at which

to 9 832/0 ^ SS

chem the next pulse is emitted, have a full amplitude if the anode potential of the rectifier 1 has increased noticeably. On the other hand, if the anode potential of the rectifier 1 has not increased noticeably, the fact that the trigger pulse has a limited amplitude is acceptable because the value -rr- in the anode circuit of the thyristor is necessarily limited accordingly and h is less important because of the low anode voltage is.

For the correct working of the circuit according to Fig. 8, the response time of the drive pulses applied to terminals 10 and 11 must not be so long that the through The pulse current passing through the capacitor 35 is not "sufficient to trigger the switching device 6, but in practice this does not give rise to any significant difficulty; since Driving devices are available which have a perfectly satisfactory rise time. If the Circuit is used in a DC system, in which kept the anode of the rectifier 1 at a constant potential for an extended period is applied without any trigger pulses there may be a possibility that the charge of the Capacitor 5 is scattered over different leakage paths. In these circumstances it may be desirable to use the capacitor J to connect a very high resistance in parallel. at AC power circuits do not need this because the AC voltage to the rectifier 1 ensures that

|: t3f95

the capacitor 5 defies minimal leakage losses charged state is maintained. .

The circuit protection * those in the, circuits; According to Figures 1, 3 ·, -4 and J is formed by the thyristor , 6 ", g, or at most dtareii ... a. liobe visual speed feafe, a Q-light operated yorricshttm-g or some other corresponding ¥ orriehtiang. replaced, are ^ '-_ / - /'

In the Stroßikkreis described above and shown in the Zeiehniang, the EondeBsator ^ -dei ^fe the storage device forms ^ in eatspreehender itbandiang .doirela a suitable secondary cell can be replaced.

Furthermore köhnea the stro-nikkreis according to the fig: uren 1 * 5 # 4, 6, 7 "ttnd 8 in eiaetn; steijerbarea Afollweilen-GBleielirieliterstromkreis of the general kind *. M-he was described with reference to fig. 5 _s be, .. The invention is not limited to such circuits ».

^8m

Claims (1)

"1838958 - l8 -. ■■. '■ ■■ ": ■.' ■■ '■■ : 3? At withdrawal> Circuit with controllable GI eieiit he, marked even by means of gowns that respond to the voltage on one, victorious, who is intended to charge a controllable rectifier to charge a monitor, ie a "switching instruction, which fee in the Arfoeitea aßspriehli applied control signal, ura The memory * - 'VQPi-ieh'tuBg. with eiiiero iriggereingaia ^ sanscblTaS des fcapen Gleiciiriciit.ers zb ^ rerbindeHi jand so a tl voff.SE! ergie - from the- SpeicIter ^ Oirr-iehtiirig to dea rectifier 'gliehiea »to initiate the Leifceadwe-rden-.des. afeeuei-feareii GlsictiPiebfeeps * 2. The circuit according to iünspirtieh 1 _Λ dad "rch marked, -that the elements which respond to the voltage on the path mentioned *, ν-isi in -healed capacitors have, one of which the storage device ■ foildefe> and that one in one direction leiten.de Forriehtüng is provided, which only a unidirectional current flow between the one capacitor over the other / allows * 3. Stroffikreis according to claim 1 or 2, characterized marked. draws ^ that. ges'ciialt in a ülaer the SpeichervorriehtTong et en lie -.vorgesehen means are * which limit the voltage as their a vorbestiraiKten value. . ■. . ^. Circuit according to claim 3, characterized gekennzeiahnet "that the said Kittel a Zenerdiade contain ^. ^; '-: -..-., 5. Circuit according to claim. 3 or. 4, characterized in that said means in a way over the
Storage device 'and the unidirectional conductive device are connected. 6. Circuit according to one of claims 2, 3 and. 4, characterized in that a further, in one "direction.
conductive device is connected in series with a resistor across the former device which is conductive in one direction and the one capacitor to be blocked when the latter device is conductive. . _ 7 · Circuit according to one of the preceding claims, characterized in that the switching device
triggerable diode and "means for applying trigger signals to the triggerable diode. 8. circuit according to claim 7, characterized in that in the path between the storage device and the
triggerable diode a blocking device provided
is, 'which is an absorption of the .. trigger signal by the
Storage device prevented. y. Circuit according to one of Claims 1 to 6, characterized in that the switching device has a controllable semiconductor rectifier with an input electrode, an output electrode and a trigger electrode as well
Has means for applying trigger signals to them. 10. Circuit according to one of the preceding claims, characterized in that the means for applying BATHROOM QRiGlHAL
109837/0765 Trigger signals contain a safety device, before the switching device works for. the case .vex »-.,:. prevent the voltage from affecting the memory device, smaller "- ■ = as a predetermined value. ■ -, - · ■ - ... 11. Circuit according to claims 9 and 1O> characterized _: -._ characterized in that the = safety device eipe: contains zener diode, via which, and a. _: TransIstor, ·., Whose ■ _, ..; .- .. ■. ■ one electrode is connected to the storage device; *: - -; ■ trigger signals, to the switching device; be created. 12. Circuit according to claim ^ 9>. Characterized in that the. The path for trigger signals to the holding device runs through the trigger electrode of the first-mentioned controllable rectifier and the output electrode of the switching device, so that the trigger signal fed to the first-mentioned controllable rectifier partly consists of energy from the Memory device and partially consists of the control signal. . ■ - - .. -: ■ _: .... 15. Circuit according to claim 12, characterized in -.... net that the control signal via a diode to the trigger electrode the switching device is applied. 14 ·. Circuit according to Claim Ij5, characterized by ■ Another diode, which has an input connection to which the control signal is applied, connects to the input electrode of the switching device. 15. Circuit according to one of claims 9, 12 / IJ and; 14, characterized in that the switching device * - fNA 163 & 958 device bypassing the current path a shunt device arranged and that means are provided which the bypass device make conductive to 'the river of Haltestr-om in the switching device when a control signal pulse ceases to prevent. 16. Circuit according to claim 15 »thereby gekennzaichnet ,. that the bypass device consists of a transistor. :: 17. Circuit according to claim I5 or 16, characterized by means which cause the transistor shortly after the start of the flow of forward current in the Switching device in response to a control signal pulse initiate / the a current flow in the transistor to sustains shortly after the control signal pulse has ceased. 18. Circuit according to one of the preceding. _; Claims, characterized in that it is arranged in a full-wave rectification circuit which has two branches with controllable rectifiers, the one storage device being a common storage device for energy which initiates the alternating conduction of controllable rectifiers in the corresponding branches.