DE3544955A1 - Power supply unit with chopper for producing a DC voltage from an AC voltage - Google Patents

Abstract

The power supply unit is an AC/DC voltage converter with an insulating transformer (3) whose primary voltage (4) is chopped by a transistor (8) at a fixed duty ratio. The secondary voltage (5) is chopped and smoothed by means of a switch or interruptor or transistor (10). The DC voltage at the load (1) connections is controlled by means of a comparator (17) and a multivibrator circuit (19) which controls the switch or transistor (10) in the secondary circuit. <??>The power supply unit can regulate the voltage for a plurality of loads with a constant accuracy in that a plurality of mutually comparable circuits are connected to the secondary winding of the single transformer. Such a power supply unit is particularly suitable for telex machines (Fig. 1). <IMAGE>

Description

DIPL.-ING. P.-C. SROKA, - DK. "H.-FEDE R, -. DHHr .- 'PHYS. DR. W. ~ D. FEDER

PATENTANWÄLTE & EUROPEAN PATENT ATTORNEYS

KLAUS O. WALTER

LAWYER DOMINIKANERSTR. 37, POST BOX 111Ο36

D-4OOO DÜSSELDORF phone (0211) 5740 22 telex 8584 550

THE

YOUR SIGN: MY SIGN:

5 ο cie L 3 D ' \ nr> Iinations Henerales

D ¹ Electric! Te o ^; ; de Mecnnique saws

6, avenue ei 'Tena

7 5783 Paris Cedeχ 16 / France

Power supply unit with chopper for generating a direct voltage from a 'iechselsnannunn

The invention hits ο in Net ^ norf't with a chopper, containing oinon Gleichricntar to rectify cJr? r AC voltage of a network and a Isolisr high frequency transformer with primer and secondary winding No polarity, of which the primary winding to the rectifier is used to rectify the mains voltage and the power supply to at least a load are connected, "although in the primary circuit the transformer limbs for interruption or chopping the voltage and in the secondary circuit

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of the transformer, a torque converter, a smoothing circuit between the chopped up voltage of the secondary circuit and elements for the regulation of the DC voltage at the connections of the load, which are able to transmit the chopped and smoothed voltage of the circuit of the ; Transformer with a comparative standard to operate and regulate.

1Π Such a supply η with one of a different voltage operated by means of an AC / DC voltage converter is described in F3-PS 2 37 A 7 ή η be κ chrieh »η: this 3 s be -ί η η η 13 S y π te η ent h ä Reqeleinriclitunncn, yy to control the Znrhnciisrrlied-sr d ^ s Pr i-Rärlcreises and i-η 5e! <unn ^? "ir" ireir as chopper or interrupter ¹ ierier Qleiehricntor ^ Ieniente.

A derartines Ketznp.r'At Knnn in a wide variety AoDRFPtsn verr'endet -.- ground, beisoielrr-jeise η th in conjunction with Fernsöhner, typewriters and telex machines.

Such barley made me bsi πγοΠοπ changes the mains voltage a "eininerna ^ nn satisfactory Efficiency, also relatively high Load fluctuations are absorbed.

The voltage at the connections of the load - is regulated and then kept constant by the control unit or regulation of the power ratio of the chopping element to hrlten to andereti constant Given the i'nterbreeiierbz · -.? !. switching ^ EE ^ h 'nndiokeit of' \ i \ cien market befindliehen chopper Ίϊζ · ί Unterbrochernliedern.

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can any renel voltage in satisfactory With a suitable number of turns of the windings of the high frequency transformer will. It is an insulating transformer, which is also a regulating transformer.

Due to the identical polarity of the transformer windings, the chopper elements and the rectifier elements conduct the secondary voltage, while the chopper elements of the primary circuit also conduct. The supply in question is thus a direct E η erqie über ρ. π u η π.

If in the case of such a supply or a such an emergency device a second load or even more Loads are to be supplied, you can use a second secondary winding with the transformer in the transformer Provide a suitable turn indicator and one Connections are identical to the first circuit the second secondary winding of the transformer, whereby iTian still has a precisely regulated load voltage e r h a11eη can.

However, if, for example, the second secondary circuit of the transformer is used to print a teleprinter k ο ρ f with very g r ο B e η L a s t s c h vj a η k u η g e η, which, if it does not hit, this second-second circle turns into an open circle, it can happen precisely in this case that the chopped up and rectified secondary voltage at the connections the smoothing device remains, which can no longer fulfill its role, which is usually the case existing! 'ondonr.ator is no longer in a Hiode called "free wheel" can unload, which is also present in ci ^ r Hegel. To this one

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To avoid disadvantage, one is forced to either • Provide a residual load or a Zener diad to reduce the Keep output current above a threshold value and to prevent »that the output voltage above a substantial square-wave voltage range increases.

However, the elimination of this one drawback results to the creation of a second disadvantage. Under the An would take that the scheme in the first secondary circuit fully always takes place satisfactorily, in practice the regulation in the second secondary circuit with a variable load, due to the presence this residual resistance or this Zener diode, not take place in a comparable manner satisfactorily.

The zener diode has a certain tolerance which it prevents the coupling failure between the secondary winding of the variable load Circuit and the primary winding of the transformer balance.

As far as the residual resistance is concerned, it would be necessary that «a value can be changed so that the output voltage of the circuit is stabilized. The tolerance with regard to the regulation of the second load circuit is further increased by the fact that two secondary windings of the transformer are coupled.

, Ηβη therefore knew one or the other of two lions b # echr§n'.en, if one does not have several want to provide complete, self-contained devices · One could first of all add a second rule for provide for the second secondary kreia. If it is is a linear regulator, the line is

! <unnecessarily the anorcinunn sink. If it is a re-oiler in the form of a chopping device, as it is the case with the first controller with an oscillator described above, increases the Multiplicity of these oscillatorsn the total effort for the power supply unit.

You can also have several parallel Converter at the output of the rectifier circuit for the Provide mains voltage. If in this case the respective chopper frequencies of the handlers are different overlay problems arise.

In addition to the disadvantages described above, it should also be noted that the control devices for the chopping elements often photocouplers for the primary voltage use whose costs are considerable, or isolating transformers, whose satisfactory coupling can be achieved schi-jer, vjooei continue to be taken into account is, since the coupling has several secondary windings to the primary connector of the pulse transformer is also difficult to achieve. Therefore secondary control systems are indispensable.

To remedy the disadvantages outlined and at least all secunication devices closed avoid, is in the JA-PS 54 167 109 a power supply proposed in which the chopper or interrupters songs i "! primary circle dos transformer have a fixed lead ratio, »the chopper limbs all the time designed for the voltage of the secondary circuit of the Trp.nsfornators and the Regeiunnseinrichtung are that they are the chopper or breaker limb control.

With such a device, the reaction loop is created

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from the secondary circuit initially ^Prin:; circle avoided. The chopper or breaker} ieder for the primary voltage are however ο in a transistor, r'er a relatively high current zsrhakken bz'i. interrupt nut. This results in an overall sense of urgency, and such a device may be necessary to switch the transistor on before you switch it on. The accuracy of this device is low, since the secondary measurement, which is regulated or controlled, can deviate from the expected value in which the ratio of the disconnectors in the secondary circuit is controlled.

The invention serves the purpose of closing the round, which remedies the well-known system "a; i ^; ^ _; f tr; η de η ■! Eighth Io.

To solve this problem, the invented power supply unit with chopper contains -inon rectifiers for rectifying a network and an isolating high-frequency transformer with primary and secondary windings of the same polarity, the primary of which are connected to the rectifier and the se ku η d 3 r vj ic! <1 u η η are connected to at least one load, -mith in the primary circuit of the transformer voltage chopping songs and in the secondary circuit of the transformer a voltage chopping element, a '"! lättunnnschnltunc z>. in smoothing the divided tension dec? Sakunr'nrkroises and links for regulating the equal snonnuriH on ^r ''; n Aris connections of the load, which are in d-? r Ln "3, the ze * 'h ac!'. te and to compare and regulate the smoothed Snannunn of the secondary voltage of the transformer τ with a constant voltage, '- ied dor, Se '', unc'.är '; reir.es and the pic-

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- in -

gelungsglieder are designed such that the ReqelungsgliecJer control the chopper element of the secondary circuit, characterized in that the control elements contain a flip-flop which is suitable is to control the chopper of the secondary circuit so that it is in the rising front or Fronts of the voltage pulses of the secondary winding becomes conductive while it is the chopper at the times at which the output voltage at the connections of the load equals the DC voltage exceeds, locks or blocked.

The chopper element or elements of the secondary circuit can preferably be a transistor of the non or type pnp, a thyristor, a switch or breaker with two stable states or any other include appropriate term, which on the principle of "all or nothing" (completely or not at all permeable) is effective.

In the device according to the invention, the accuracy depends the regulation no longer depends on the coupling in the transformer, but solely on the accuracy the reference or DC voltage, the accuracy of the comparator circuit and the response speed of the control circuit.

Dan erfindunnsgenäße device also has the advantage DA8 can be connected in parallel on the Sekundärriicklung more regulated load circuits with different voltages without daft one must increase the number of oscillators, as in de ^r n primary chopper circuit, a single oscillator for controlling a Zerhakkertransistors sufficient.

The invention is illustrated below with reference to the drawing

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described in more detail, "s zoigen:

Fig. 1 the electrical circuit diagram of the inventive butcher ^r iit a single lantern

circle,
Fig. 2 shows the electrical scheme of a supply system

direction "nit zv; ei Lantkrnisen:

FIGS. 3A to 3C show the X curves of the primary voltage Primary current and the switching losses do »s Control transistor for the transformer of the IG he f indungsne-a ^ .ilen device; Figures 4A to 4C are analogous to the manufacture of Figure 3

Curves with advancing the blocking or blocking of the Snkundnrtransistoren, and FIGS. 5A to 5C for the illustration of FIG. 4 analog Curves, however, with a reduction in the state of safety of the secondary transistors.

According to FIG. 1, the same voltage occurs as one Load 1 based on a '-'schselspannunn one

2Q available network 2. The device comprises an isolating high-frequency transformer 3 - for example designed for 30 i <Hz - with high mutual inductance and low leakage inductance and equipped with primary and secondary windings A or. 5 same polarity. The primary winding 4 of the transformer 3 is connected to the output ei η or the usual diode rectifier bridge 6, the input of which is connected to the Metz 2.

The rectified voltage dos Ms'-zes 1 is applied to the primary winding 4 of the transformer and chopped up by means of a fixed-frequency oscillator 7, which controls a chopper or switching transistor Π via the base, and thus with a fixed ratio; This transistor β P. is in series with the primary Jickluno 4. Dis of the "back ^r i rectified

Voltage 'jxrd filtered or filtered by a capacitor 9 smoothed.

The secondary winding 5 of the transformer 3 is connected to the load 1 with the interposition of an interrupter or Zerhaclorschalters ID and a smoothing circuit 11 in series. The smoothing circuit 11 contains an ^{induction coil 12 lying in series with de r} o. Switch 10, which is connected between a capacitor 13 and a protective or safety diode 14, referred to as a "freewheel", which switches the secondary winding 5 and the switch '■> bridged in series, so that only the discharge current of the capacitor is allowed through parallel to the load 1 when the switch 10 is open.

A resistor divider bridge, such as the resistors 15 and 1ί> of predetermined values, is connected in parallel to the load 1 in order to branch off part of the output DC voltage V j 4 and to a reference voltage

1 y y. O

To compare M ρ in a comparator 17 that

ref - ^J '

at one of its entrances, and at the negative, this part of the Ausnannsspnnnunn and at its other entrance, the; positive receives the reference voltage V -. The output (in the comparator 17 is connected to the Kullstollungseinganr; 13 of a bistable multivibrator 19, the input 20 of which is connected to the input of the switch IH, and the output 21 of which controls the switching on of the switch or interrupter2 10. The bridge 15, 16, the comparator 17 and the cinema circuit 19 form a control loop. ^r 'ei of the rising front or front side of the LiDulBon odor Rechteckirnpulsen

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- 1 T _

Voltage at the connections for "oicunnrir'Micklun" 5 of the transformer 3, ie the I ipuls "., Which are generated by the chopper transistor;! Her primary winding, / <. , Changes the K irnschs.ltunn 19 the state in order to close the switch 1 before another change of state is effected - and to control the opening of the switch 10 as soon as the foreseeable part of the output can be reached at the connections of the load 1 _o _ überorsteiqt.

The chopper bziv. Unswitching the switch will nsrnnG Fio. To ensure Z preferably by a PRN ^T Transistor 1Π. So that the Transintor 10 is not restricted or impaired by the nominal half-periods of the Snannunri en the connections of the secondary winding 5 of the Transformer 3, ne ^ ri ^p , Fin. ?. z '/ iischen the F.ekundar ^ iclilunq 5 and the transistor I ¹ ? a protective bz-i. Fuse diode? .3 connected in series n ^. In the event that the unswitching function of the power circuit is achieved or brought about by means of a thyristor, such a protective diode is no longer required. The closing of the switch disposes of the conduction state of the Trnnsiotors IH, and r '^^ open the switch of the Snerrstatus of the Trinsistorπ, if

2 "? The not'-jendine Fne ^ nio in the Snulo 1 *?

If several loads need to be supplied with different voltages, as is the case, for example, with a teleprinter, which reads a hotno and a Hruckkoof in individual microprocessors, sleeps. ^r inn nnvallnl to the secondary reviclilunri 5 of the Trensforriatnr3 3 the loads to be cornified according to ν in Io id "n ^v 5se '." Reise, the different suns ϋηΓττη, with their ^: ' eoelschleifen

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at. In fin. 2 there are two reading circles with each other
corresponding elements shown, the same ": Chen Bezunszeichen vjie in Fin have 1, wherein the loading; reference symbols of the second circle, respectively an index '.

stroke is assigned. These two circles are of- ' ! mutually independent, and stabilizing the off. { output voltage of one circuit has no influence on j

that of the other circle. I.

The performance of the cargo trip according to FIG. 1

or one of the circles according to Fig. 2 depends a lot on]

the Schaltver.lusten of the transistor 8 of the first;

Circle. j

Referring to FIGS. 3A and 33, as i

Function over time t, I of the i in the primary winding

4 the current flowing through the transformer 3, which is the sum '

of the seconds to be traced back to the primary winding .

contains dark tones, and V / the voltage at the terminals;,

Be connections or terminals of the transistor 3. The ^;

Switching losses in the Transintor 0 are shown in Fig. 3C!

illustrated by the signal P, namely as a multi- \

plication of the signals J and V. It is ·

not negligible impulse losses, which occur with each ) change of state at time t. (Conclude)
t. , -ι (open or Soerren) .... of the transistor 8

appear. '

If you look at the ratio between the number of 1 children

the primary winding ή and the number of turns of the Se- ^

3Π secondary winding 5 of the transformer 3 determined so that
the switches or transistors ID, 10 ', .... systematically interrupt or block before the transistor 8,
and that is exactly what the regulation aims at,
in view of the coupling between the winding

gene and corresponding to the curves according to FIG. 4A,

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48, 4C, the primary current I ¹ is almost at zero, the transistor ⁿ blocks and the voltage U ¹ starts to grow, due to the power loss P 'of the transistor Π, with the primary current I ¹ before the "Open deo transistor B sin first time when opening t" of one of the

both transistors IP, I ¹ V and a second time at the 7th

Open t '"" of the other of the two Trnnsisto-

ren 10, 10 * started to fall off.

If, in addition, by means of '-'erzöoerunoselements, as are customary in secondary circuits, the action of the flip-flop 19 never delaying the conduction or the conduction of the tronsistors 10, If! ¹ related to the transistor ⁿ > ntRinrt, '\ ^! obei according to the curves of FIGS. 5A, 5Π, 5C di ⁿ . Soannunn \ / '' almost is zero, iicnn the transistor B by letting "IIRD and Primärstron T ^'1 a remarkable !! considerably art achieved reduced ~> .nr \ losses when ^closing!' Jobei the Primärstron I ¹ 'after the transistor ° has slept, only snfännt to rise, namely a first nal leg closing t "^ one of the two transistors 1Π, ID ¹ and a second time when closing t _{f of} the other of the two transistors 10, 1Π'.

In the case of leading bz? I. Prevention of blocking and, in the case of '.'erzöoerunn, of the on-state of the transistors 10, l ⁿ '. In other words, based on the states of the transistor "-. 'The commutation losses are negligible. In this case, nan not the auxiliary networks f "; r the 'ioronutation bzvj. Hm circuit of the transistor Π provide, i-jenn the rectified voltage of the Metzes ? is increased.

The Reqelunn of Stronvarsnrnunn is how it is

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from the above, .very simple, and the appropriate The device can be integrated into a housing that does not take up more space than a linear control housing.

The control circuit described above can also Protective circuits or - Trips can be assigned, for example a current limiting circuit, an overvoltage protection circuit, a temperature fuse π u si ·]. .

Whether a power supply with positive voltages is described morden, the invention can also be used in connection with the power supply of loads negative DC voltages can be used. For this purpose, it is sufficient, for example, to connect the connections or terminals the protection or backup diodes 23, 23 ', as well as those the "free wheeling" diodes 14, 14 'and the smoothing conicers 13, 13 'to swap and chopper transistors of type non to be provided.

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Claims (1)

P a t e η t a η s η r ü c h e 1. Power supply unit with chopper, containing a rectifier (6) for rectifying the voltage of a network (2) and an isolating high-frequency transformer (3) with primary and secondary windings (h, 5) of the same polarity, of which the primary winding (4) is connected the rectifier (■ ") and the secondary winding (5) are connected to at least one load (1), whereby in the primary transformer (3) Spannunqszerhackernlieder (7, 0) and in dom secondary circuit of the transformer (3) a voltage chopper (ID), a smoothing circuit (11) for smoothing the chopped up voltage of the secondary circle and limbs for regulating the direct voltage at the connections f £ the load (1), which are able to destroy the ^ Chopped and smoothed voltage of the secondary circuit of the transformer lit a'3r the DC voltage to compare and reciein, "with the chopping elements (7, S) have a fixed conduction ratio and the Spannunnszerhackernlied (1 ^r >) and the regulating elements (22) designed in this way are that the chopping members (22) control the chopping member (10), characterized in that the ^ sgelungsglierier contain a toggle circuit (19) which is suitable to control the chopping member (10) in such a way that it is at the rising front - or front sides of the voltage pulses of the secondary winding (5) pass through, while the chopper element blocks or blocks at the times at which the output voltage at the connections of the load overturns the DC voltage. 2. Metzgsrät with chopper according to claim 1, characterized in that ^r 'the'Or'nr-ltnisz'iisc-τοη the Hindunnsnnzahl dor Pr! - "!" Micki tinn (■ · '! ■) and dnr Windurms- BATH ORIGINAL number of secondary windings ('}) dRB transformer (3) set int such that the times of blocking hzn. ^r ! lnck.ierens the Zsrnackerqliedes (1Π) in the S e! <and S r k r ο i π are systematically in front of ri e τι je η i π e η of the chopper elements (7, 3) of the primary circle. 3. I.'etzgerät η it chopper according to claim 1 or ?., Characterized in that dnO members are provided to delay the action of the! 'Inoschaltung (S') which controls the passage throughput res chopper member (1Π). H. Meat chopper according to one of Claims 1 to 3, characterized in that the flip-switch (19) is connected with a gauze reset input (IR) to the output of a comparator (17) which is connected to its Inputs the load voltage and the comparison voltage. 5. Power supply unit with chopper according to one of claims 1 to 4, characterized in that the chopper members the primary circuit is a fixed frequency oscillator (7), which controls a Rlied (0) that is completely or does not let through in series with the primary winding (4) of the transformer. 6. Butcher -iit chopper according to one of three claims 1 to 5, characterized in that the chopper member of the secondary circuit has a member (1Π), rjelches is completely or not at all permeable. 7. Power supply unit tit chopper nncn claim 6, characterized characterized that this song is a thyristor. 0. power supply unit ^r nit Chopper according to claim 6, characterized in that this member is a DAT transistor, BATH ORIGINAL which lies with a protection or safety diode in ^r '.oihe. 9. Power supply unit with chopper according to one of claims 1 to B, characterized in that several Lpstkreise, each of which Zerhackerπlieder (10, 3.0 ¹ ) for the secondary soannunn, ni ^ ttuntiscjliedsr (11, II ¹ ) and Regelqlieder (?.?. , 2 ¹ ^. ') Auf'joist, oara.13.e3. to the Sekunrinr'-iickiunn (5) the Trans fornators (j?) are anreschlnsson. BATH ORIGINAL