US3408554A

US3408554A - Combined magnetic regulator and transformer

Info

Publication number: US3408554A
Application number: US530309A
Authority: US
Inventors: Joseph A Fingerett
Original assignee: Deutsche ITT Industries GmbH
Current assignee: TDK Micronas GmbH; ITT Inc
Priority date: 1966-02-28
Filing date: 1966-02-28
Publication date: 1968-10-29
Anticipated expiration: 1985-10-29
Also published as: GB1178003A; NL6703128A; BE694734A; DE1638318A1

Description

0a. 29, 1968 J. A. FINGERETT 3, 8

COMBINED MAGNETIC REGULATOR AND TRANSFORMER 4 Sheets-Sheet 1 Filed Feb. 28, 1966 INVENTOR. 8:00 A. mvaenerr Pac Oct. 29, 1968 J. A. FINGERETT 3,408,554

COMBINED MAGNETIC REGULATOR Filed Feb. 28, 1966 A ac AND TRANSFORMER 4 Sheets-Sheet 2 INVENTOR, JOSEPH A .Fl/VGERET? ATTORNEY Oct. 29, 1968 3,408,554

COMBINED MAGNETIC REGULATOR AND TRANSFORMER J. A. FINGERETT 4 Sheets-Sheet 3 Filed Feb. 28, 1966 INVENTOR JOSEPH A F/IVGfRETT wz Ms b 6080 .SGQvSu wbkviwwbw wweio m ATTORNEY Oct. 29, 1968 J A, HNGERETT 3,408,554

COMBINED MAGNETIC REGULATOR AND TRANSFORMER Filed Feb. 28, 1966 4 Sheets-Sheet 4 OUTPUT INVENTOR. JOSEPH A. FINGERETT ATTORNEY 3,408,554 COMBINED MAGNETIC REGULATOR AND TRANSFORMER Joseph A. Fingerett, Van Nuys, Calif., assignor t International Telephone and Telegraph Corporation, Nutley,

.J., a corporation of Maryland Filed Feb. 28, 1966, Ser. No. 530,309 11 Claims. (Cl. 321---18) ABSTRACT OF THE DISCLOSURE A magnetic regulator compactly combined with a transformer by winding primary and secondary transformer and maintain the voltage across said load substantially constant regardless of variations in the AC. input voltage or load impedance.

This invention relates to magnetic regulators and more particularly to a combined magnetic regulator and transformer.

A feature of this invention is that by winding a common transformer and magnetic regulator.

The above-mentioned and other objects and features of this invention will become apparent by reference to the following description taken in conjunction with the acaccompanying drawings in which:

FIGURE 1 is a schematic illustration of a magnetic regulator and transformer according to this invention;

FIGURE 2 is a schematic illustration of the waveforms generated at various points in the circuit of FIGURE 1;

FIGURE 3 is a schematic illustration of a feedback-type regulated voltage supply according to this invention;

FIGURE 4 is a representation of the physical structure of the transformer and magnetic regulator according to this invention;

FIGURE 5 is a schematic diagram of a 3-phase circuit according to the principles of this invention, and

FIGURE 6 is an illustration of the Waveforms generated at various points in the circuit of FIGURE 5.

i United States Patent 0 is the same as the alternating current supply multipliet by either the step-up or step-down ratio between winding: Essentially, the coaction of windings W1 anc of winding W2 is coupled to the load R via diode CR2 and a full Wave rectifier comprising diodes CR3 and CR4. Connected between the full wave rectifier and the load is to the output signal produced across winding W2.

Windings W4A and W4B coupled with the Windings on the primary side of said transformers (windings W1, W3A and W3B) operate as a standard magnetic controller, the operation of which is widely known in the art and is described in numerous textbooks and articles (see for example, Magnetic-Amplifier Circuits by Geyger, second edition, pages 264-268). Therefore, a description thereof will not be undertaken here. FIGURES 2A through 2H illustrate the waveforms appearing at various points in the magnetic regulator section of the circuit of FIGURE 1 which comprises windings W1, W3A, W3B, W4A and W4B. The output of the alternating current e is shown in FIGURE 2A as a square wave in order to simplify an analysis of the circuit. It is apparent that many other alternating current signals may be utilized instead of a square W4B, respectively.

The output of winding W2 diodes CR3 and CR4 and is coupled to the load R via a diode CR2. The output voltage supplied to the load R when E =0 is merely a full wave rectified version of the alternating input signal. This output is illustrated in FIG- generate the signal shown in FIGURE 2K. When E is again zero, the output to load R is merely the full wave rectified alternating signal (see magnitude of DC. control signal E As shown in FIG- URE 2 when the control signal E is decreased (see signal 23, FIGURE 2B) pulses of shorter duration is full wave rectified by FIGURE 3 illustrates the basic circuit of FIGURE 1 ut further including means for developing an error voltge E proportional to the deviation of the output voltage rom a desired value. The error voltage E is obtained by means of the differential coupling of R1, R2, R3 and refernce diode CR7. The junction between resistor R3 and refrence diode CR7 is positive with respect to the junction )etween resistors R1 and R2. The D.C. voltage E obtained rom this differential connection is applied to windings WSA and W3B in the same manner as was the control signal E in FIGURE 1. The operation of this circuit is identical to the operation of the circuit of FIGURE 1. If the voltage across resistor R increases, the error voltage E will decrease, thereby causing the duration of the pulses added to the output of the full wave rectifier to decrease. This decreases the average voltage supplied to the load. Conversely, when the voltage across R decreases, E will increase, thereby increasing the duration of the pulses added to the output of said full wave rectifier. In this manner it is seen that the circuit of FIGURE 3 operates as a voltage regulated supply. The circuit of FIGURE 3 utilizes a bridge-type full wave rectifier comprising diodes CR3- CR6 instead of the two diode-type full wave rectifier shown in FIGURE 1. This substitution has no effect on the operation of the circuit and is merely shown by way of example.

FIGURE 4 illustrates a physical embodiment of the transformer and regulator according to this invention. It is seen that windings W1 and W2 are wound in common on

cores

2 and 3 to provide the aforementioned advantages. As was previously mentioned, the novel part of this invention lies in the addition of winding W2 to the previously known magnetic regulators and in the manner of placing windings W1 and W2 in common onto two transformer cores. In this manner the amount of iron core required for a given power output is substantially reduced over the prior art circuits which utilize separate regulators and transformers.

In FIGURE there is shown a schematic diagram of a 3-phase circuit according to this invention. Applied to the primary windings P through P is a 3-phase alternating current source. Also wound on the cores are primary control windings C through C to which is applied control voltage E The secondary windings S through S are coupled to load R via diodes D through D Secondary windings S through S are also coupled to load R via diodes D5 through D such that the output from windings 8 -8 and from S S are additive at load R10. Note that the windings having the same subscripts are wound on the same cores. This circuit operates essentially in the same manner as three single phase structures (as shown in FIGURE 1 for example) coupled together and operating into a common load. In FIGURE 5 secondary windings S '-S supply a signal proportional to the alternating input signal to the load-Therefore, the output to the common load R comprises the voltage pulses developed by the regulator portion of the circuit (windings 8 -8 superimposed on the full wave rectified version of the input signal which is supplied by windings S -S Looking at one phase of the circuit of FIGURE 5, it is seen that windings P and P S and S S and S and C and C are analogous to the windings W1, W4A and W4B, W2 and W3A and W3B, respectively, as shown in the circuit of FIGURE 1. Note that in the discussion of the 3-phase system below the alternating current source is a three phase sinusoidal waveform as shown in FIG- URE 6A instead of the square wave input shown in FIG- URE 2A. It is apparent that any three phase alternating current input signal may be used and that the sinusoidal waveform is shown merely by way of example. A brief description of the circuit shown in FIGURE 5 taken in conjunction with the waveforms shown in FIGURE 6 appears below.

For the purposes of the following discussion it is assumed that windings S -S are not connected in the cirthe fact that P and P 4 cuit and the only output signal to the load R is supplied by windings S -S via diodes Dl-D4. The relationships:

(1) E -4.44 fN I (II19.X)

and:

(7) E =KN in) (P dt Pe 6(t) (P will yield a Et=0 1 since EAB+EBC+ECA:0

This merely states that the sum of the fluxes must be zero. This is evident since Note that Equations 14, 15, and 16 are imposed by are in series across E etc. During the portion of each cycle that both core segments are unsaturated, a second condition can be imposed (see FIGURE 5).

The time that Equation 17 is effective is from the zero crossing of the appropriate phase of the supply voltage, until saturation of one flux path of the pair. During this time, the control windings present a relatively high input impedance, and the current flow is related to the differential impedance of two unsaturated cores operating at different voltage levels.

In FIGURE 6, the three phase alternating current supply potential is shown, with typical waveforms for E and E E and E E and E will be pairwise identical, except for the relative phase displacement of the corresponding primary sources. The output resulting from the system is shown, for saturation of the first core in each pair at It is possible to provide for saturation at any phase angle between 90 and the corresponding output level going from maximum to minimum. The minimum output obtainable from this circuit is zero.

FIGURE 5 will now be discussed assuming that secondary windings S '-S are connected in the circuit as shown. These secondaries are series connected as are the primaries, so that a conventional three phase rectified output is obtained therefrom b means of diodes DS-D10. Since windings S and S are coupled together in the same relationship as are windings P and P the voltage across this series pair is related to the primary voltage through the turns ratio used. The differential voltage will not appear across the series pair.

The output obtained from windings 8 -3 (see FIG- URES 5 and 6) is superimposed onto the output obtained from the full wave rectified output of windings Sf-S This represents the three phase equivalent of the single phase circuit previously described with reference to FIG- URES l and 3.

It should be noted that the output ripple frequency from the three phase controller is at six times the supply frequency, even though only three rectifiers are used. As

was previously seen, in the single phase unit the ripple frequency was twice the supply frequency.

It is pointed out that a sensing circuit coupled from the load R to control voltage E may be added to this circuit in the same manner as in lated 3-phase voltage supply. It is not shown in the drawings in conjunction with the 3-phase circuit for the sake of clarity.

While I have described above the principles of my invention in connection with specific apparatus, it is to be invention, as setforth in the accompanying claims.

I claim:

1. A combined magnetic regulator and transformer comprising:

a first transformer core having first and second primary windings and first and second secondary windings;

core having third and fourth primary windings and third and fourth secondary windings;

said first and third primary windings being coupled in series aiding, said first and third secondary windings being coupled in series aiding, said second and fourth primary windings being coupled in series opposing, and said second and fourth secondary windings being coupled in series opposing;

means for applying an alternating current (source) to said first and third primary windings;

output means coupled to said first and third secondary windings;

means for applying a control signal to said second and fourth primary windings; and

means coupling said second and fourth secondary windings to said output means to maintain an output voltage proportional to said alternating current and said control signal.

2. A combined magnetic regulator and transformer according to claim 1 wherein said means for applying a control signal comprises:

means coupled to said output means for developing an error voltage proportional to the deviation of the output signal across said output means from a desired value; and

means coupling said error voltage to said second and fourth primary windings to maintain said output signal substantially constant.

3. The device of claim 2 wherein said means for developing an error voltage comprises a differential voltage detector coupled across said output means.

4. The device of claim 3 wherein said differential detector comprises:

first and second resistors coupled in series and across said output means;

a third resistor;

a voltage reference diode;

means coupling said third resistor and said reference diode in reference diode.

5. A combined magnetic regulator and transformer comprising:

a first transformer core having first primary windings and first secondary windings thereon;

a second transformer core having second primary windings and second secondary windings thereon;

third primary and third secondary windings wound in common on both of said cores;

means for applying an alternating current signal to said third primary windings;

output means coupled to said third secondary windings;

means for applying a control signal to said first and second primary windings; and

means coupling said first and second secondary wind ings to said output means to maintain an output volt age proportional to said alternating current signa and said control signal.

6. A combined magnetic regulator and transformer comprising:

a first transformer core having first and second primary windings and first and second secondary windings thereon;

a second transformer core having third and fourth pri mary windings and third and fourth secondary windings thereon;

means for applying an alternating current signal to said first and third primary windings;

a full wave rectifier coupled to said first and third secondary windings;

a first diode coupled to the output of said full wave rectifier;

a low pass filter coupled to said diode;

an output utilization means;

means coupling said second and fourth secondary windings to said low pass filter to maintain an output voltage proportional to said alternating current signal and said control signal.

7. The device of claim 6 wherein said means coupling said second and fourth secondary windings to said low pass 8. A combined 3-phase magnetic reguilator and transformer comprising:

a second transformer core having third and fourth primary windings and third and fourth secondary windings;

means for applying one phase of a 3-phase alternating current signal to said first and third primary windings;

a third transformer core having fifth and sixth primary windings and fifth and sixth secondary windings;

a fourth transformer core having seventh and eighth primary windings and seventh and eighth secondary windings;

means for applying a second phase of a 3-phase alternating current signal to said fifth and seventh primary windings;

a fifth transformer core windings and ninth primary windings and eleventh and twelfth secondary windings;

means for applying the third phase of a 3-phase alternating current signal to said ninth and eleventh primary windings;

means for applying a control signal to said second, fourth, sixth, eighth, tenth and twelfth primary windings; and

9. The device of claim 8 wherein said first and third in series aiding, said fifth are coupled in series aiding, said ninth and eleventh primary windings are coupled in series aiding, said second and fourth primary windings are coupled in series opposing, said sixth and eighth primary windings are coupled in series opposing, said tenth and twelfth primary windings are coupled in series opposing, said first and third secondary windings are coupled in series aiding, said fifth and seventh secondary vindings are coupled in series aiding, said ninth and :leventh secondary windings are coupled in series aiding, ;aid second and fourth secondary windings are coupled in series opposing, said sixth and eighth secondary windings are coupled in series opposing and said tenth and twelfth secondary windings are coupled in series opposing.

10. The device of claim 9 wherein said first, third, fifth, seventh, ninth, and eleventh primary windings are coupled in a 3-phase delta configuration, said second, fourth, sixth, eighth, tenth, and twelfth primary windings are coupled in series and to a DC. control signal, said first, third, fifth, seventh, ninth and eleventh secondary windings are coupled together in a 3-phase Y configuration and said second, fourth, sixth, eighth, tenth and twelfth secondary windings are coupled together in a 3-phase Y configuration.

11. The device of claim 10 further comprising a plurality of diodes,

each endpoint of the legs of said Y configurations and each neutral point of said Y configurations being coupled to said output means rality of diodes.

via oneof said plu- 5 References Cited UNITED STATES PATENTS 1,997,657 4/1935 Schmutz 321-24 XR 2,777,073 1/1957 Fingerett et a1. 323-56 XR 2,777,986 1/1957 Bennett 323-56 10 2,885,627 5/1959 Holt 323-56 3,112,440 11/1963 Moyer 323-56 3,315,151 4/1967 Wentworth 323-56 5 LEE T. HIX, Primary Examiner.

W. M. SHOOP, JR., Assistant Examiner.