US2214735A - Electrical compensator - Google Patents

Description

p 1940. L. BATCHELDER 4, 35

ELECTRICAL (-OMPENSATOR driginal Filed Jan. 6, 1933 2 Sheets-Sheet 1 INVENTOR. LA UIZENCE BATCHEL 052 WWW.

Sept. 17, 1940. BATCHELbER 2,214,735

[ELECTRICAL COMPENSATOR Original Filed Jan. SL193: 2 Sheets-Sheet 2 INVVEN TOR. LAURENCE 5A TCHELDEP Patented Sept. 17, 194

ELECTRICAL comnnsa'ron Laurence Batchelder, Cambridge, Mass, assign- -or to Submarine Signal Company, Boston, Mass,

a corporation of Maine Original application January 6, 1933, Serial No. 650,535. Divided and this application Novem- 4 her 21, 1936, Serial No. 112,058

4 Claims. (G14 17'Z386) This application is a. division of my copending application Serial No. 650,535, filed January 6, 1933, issued August 3, 1937, Patent No. 2,088,580, and relates to electric compensators.

the size that otherwise could be used. The sections could therefore be made twice the size necessary to produce the maximum change of retardation in the motion of the compensator switch allowable to preserve the continuity of the Electric compensators have been known for a impression to the observer. The result was that 5 considerable time and have been used among a compensator of fewer sections could be built other purposes for the directive reception of and that both the intermediary and final lines underwater noises and signals. Considerable .decould be made to have the same time lag. velopment along these lines was first made dur- In my Patent No. 2,088,580, referred to above, ing the World War when the use of the so-called I disclosed a further improvement in the com- 1 multispot compensation was first evolved. Elecpensator switch whereby the number of inductive tric compensators were used with. a group of section elements could be reduced by utilizing a receivers submerged in the water, either mounted pair of bridging coils which the compensator within the vessel or carried over the side, for switch connects in parallel with the normal coils m detecting the presence of other vessels such as of the retardation line. By this means it is posenemy submarines or warships. Compensators sible to obtain a mid-series termination of the used in this manner have also found application line as well as the usual mid-shunt termination along commercial lines and have been used sucwhen only a. single two-terminal inductance is cessfully in preventing collisions between vessels used in each section. This applied particularly m as well as determining the direction of some to the binaural lines and made it possible to 20 known source of sound. reduce the number of coils in these lines to half In a compensator of the present type which the number previously used. may be called a group compensator, the groups The present invention provides a further imare first individually compensated and then comprovement in the compensator switch and relates pensated as a whole between the two indicating particularly to the maximum lines. In this case 25 or telephone devices in the same general way as the number of coils and condensers is not in the prior art. In the compensators of the reduced, but a perfect termination of each secprior art having a so-called binaural line, that is tion as the length of the line is varied is made the line which compensates each group for a final possible whereby the accuracy of the compen- 80 balance, a switching arrangement is used which sator is increased. In the prior art the use of opens the line successively at difierent sections. a pair of bridging coils which can be connected The electrical contacts at the points where in parallel with one of the coils of the retardathese openings occur are often poor, because of tion line has already been suggested but such dust or small particles which come between the arrangementshave not been for the same pur- 85 contacting surfaces with the result that some pose as in the present invention, namely to pro- 85 resistance is set up in the circuit. This increases vide a proper termination of 'a portion of the the resistance on the coil side of the line'and line when its length is being varied. Accordingproduces a distortional efiect which reacts very to the present invention the bridging coils are unfavorably in creating false observations and given the same inductance values as those of 40 inaccurate balances when making a compensator the coils in the line proper. 4o

setting. Besides this, the added resistance in- This andother features of the present invencreases the attenuation of the line. tion will be evident from the following descrip- In my copending application Serial No. 600,191, tion taken in connection with the accompanying filed March 21, 1932 issued February 16, 1937, drawings in which Figure 1 shows a schematic as Patent No. 2,070,570, I showed how these difliwiring diagram of the compensator including the 45 culties could be overcome by employing a switch retardation lines both binaural and maximum arrangement in which the line is varied at the and the compensator switch; Figure 2 shows a common side and the line is therefore preserved development of a part of the switch controlling intact while the switch is being moved from secthe maximum line; and Figure 3 shows schetion to section. matically a modification of Figure l which never- 50 r This switching arrangement had the further theless retains the advantages of the present inedvantage that it was possible to increase or devention. I crease the length of the line a half section at In the present case the invention is illustrated a time so that the sections could be made twice as applied to a so-called six-spot system, but any number of spots may be used and, in fact, other 55 in a plane or in a three-dimensional space.

arrangements than those indicated in the drawings may be employed, as, for instance, a circular group or a group forming other configurations the embodiment herein described six hydrophones are installed on the starboard side of the vessel and six hydrophones on the port side. Selector switches are then provided so that the six starboard hydrophones may be employed to listen to sounds approaching from the starboard side of the vessel or the six port hydrophones may be employed to listen to sounds approaching from the port side of the vessel, or three of the starboard hydrophones and three of the port hydrophones may be employed as a cross base to listen to sounds coming from ahead.

In Fig. -1 the coils of the port receivers are represented by I'p, 2'10 6'p while the coils of the six starboard receivers are indicated as Is, 2's 6's. The hydrophones used in con-- nection with this compensator are matched directly with the lines on which the sound energy is impressed. The direct current flux excitation is supplied in series groups of three; the switches I3 and 9 applying the potential of thebattery I3 across the common I4 and each of the groups of windings I2. A selector switch I5 is provided which has three positions: a bow position as indicated in the position shown in Fig. l, a port position when rotated to the left and a starboard position when rotated to the right. For the bow position it will be noted that there is a choice of the use of the forward groups or the aft groups of three receivers. This choice may be effected by the jumper connectors I and 8 which connect the switch arms 9 and In to the connecting points F on the left or A on the right.

The jumpers I and 8 are preferably fixed when the installation is made for the best choice on the vessel and thereafter are not changed unless it is especially desired to do so. In the position of the jumpers indicated in Fig. 1, it will be noted that the forwardgroup F connecting with I'p, 2'1], 3'3) and I's, 2's and 3's is used. In the position of the jumpers on the right contact points A the receivers lp, 5'10 and 6'1) and 4's, 5's and 6's would be connected to the compensator. The switch 9 in its downward position is connected with the two switch points whose combination is designated 93. In this relation the jumpers 6 sloping to the left energize the coils in the receivers Ip, 2'1), 3'10 and Is, 2's and 3's. With the jumpers 8 in the other position the rear orthe end of the fixed or F-line while the receiver 3'12 is connected atthe right end of the .C-line. The energies from the receivers thus compensated in a fixed fashion are impressed by means of the connecting lead I6 to the common of onehalf of the B-line as indicated by the numeral I1 applied to the right half of the ring I8.

Similarly the starboard half group is connected to the left'connector I9 of the ring I8 by means of the connecting lead 2Il- In this case the starboard receiver Is connected through the 43 position of the switch l connects to the left end of the C-line while the receiver 3's connects through the switch point 63 to the right of the C-line, and the receiver 2's connects through the switch point 53 to the F-line. The energy from the three receivers is conducted over the line 22 to the B-line through the lead 2| and also to one terminal 23 of the binaural headphone 24. The other phone lead 25 connects to the opposite end of the B-line and similarly also one terminal of the phone 26 is connected to the other extreme end of the B-line.

The description above illustrates the switching arrangement for the so-called bow position.

In the port and starboard positions the switch arm I is moved to the left and right, respectively, that is to the left for the port position and to the right for the starboard position. In the port position the receivers Ip, 2'p and'3'p are connected to the left end of the C-line, the end of the F-line and the right end of the C-line,

contacts 62, and 63 and 64, 30 and 65, re-

spectively, unite the impulses passing through each F-line and its corresponding C-line at the correct points to produce the desired compensation to compensate for the difference in time of arrival of the wave energy at the receivers of each group.

As will be noted, the switch contacts 62, 20 and 63 and 64, 30 and 65 are adapted to move over the contact studs to 36, inclusive, and 31 to 42, inclusive, respectively; each stud connecting to a different point on the left and right C-lines, respectively. The contact switches 62, 20 and 63, and 64, 30, and 65 move simultaneously on the same mechanism as the ring I8 and the switch brushes 43, 51 and 44: the position of the contact switches 62, 20 and 63, and 64, 30 and I 65 adjusting the compensation of the C-lines and the position of the ring .I8 and the contact brushes 43, 51 and 44 adjusting the compensation of the B-line.

As indicated in Fig. 1 the energy from the left F- and C-lines is fed into the B-line by the two conductors comprising the lead I6 together with a portion H of the ring I8 and the brushes 44 and 51 while the energy from the right F- and C-lines is-fed into the B-line by means 'of the conductors 22 and 2| together with the portion I9 of the ring I8 and the brushes .43 and 51. The ring I8 and the brushes 43, 51 and 44 move simultaneously breaking the B-line each half section in its motion. This is accomplished as follows: 1

The B-line is composed of series inductances I 46, 46, etc., which with the condensers 50, 50, etc., form the sections of the line. The condensers 50 are connected between the series inductances and the common. The line sections may be considered as either T sections or 1r sections, and are, in fact, first one and then the other, depending upon the switch positions. It should be noted, however, that whether the sections are considered to be 1r or T sections, there is required only one twoterminal inductance coil-per section. The condensers 50,v 50, etc., are connected by means of the brushes 5i, 5I, etc., to the ring I8, while the inductances 46, 46, etc., are connected together in series and are also connected -at their junctions to the studs 52, 52, etc.

Between the halves l1 and I9 of the ring I8 there is an insulating element 53 which carries two conducting. segments 54, 55 spaced somewhat to position a but less than the width of the brushes 5| from the segments i9 and I1, respectively, of the ring l8. These segments 54 and 55 are connected to the segments I9 and il through condensers 56 and 56 of the same capacity as the condensers 50.

Between the brushes 43 and 51 there is connected an inductance ll of the same value as the effective series inductance per section of line. Likewise between the brushes 51 and 44 there is connected an inductance 12 of the same value as the inductance II. By making the values of the inductances H and 12 of the same value as the efiective series inductance of the line, in this case substantially that of coils 46, the effective terminating inductance for each half of the line will be equal to half of the inductance of coil 46 since both H and 12 are connected in parallel with one of the coils 46.

In the C-lines the inductances are all connected in series and each of their connecting points are also connected to a contact stud. The condensers making up the C-lines are shunted between the connecting points of the inductances and a common. The adjustment of the C-lines is not made by opening the common as in the case of the B-line, but by connecting to the junction points of the series inductances. Y

The brushes 62, 20, 63, and 64, 30, divide each of the two C-lines into two parts, respective- .ly; Inductances 58, 59, 60 and BI are connected between the several brushes, as shown, in order that the parts of the C-lines may be given proper terminations. The operation of the C-line ad justment is indicated in Fig. 2 by the development of the switch controlling the left C-line.

, In the position a the brushes 52, 63 are making connection with the contact studs 35 and 35, respectively. The inductances 58 and 59 each have an inductance of a value one-half that of the eifective series inductance per section of line. The energy is taken oif the line through the brush 29 which in position a connects to the line only through the inductances 58 and 59. If we suppose the energies entering at each end of the line arrive in phase at coil 13, then coil i3 will be at a current node. Therefore, the coil 13 has no efiect at all and one half of the line is terminated in the inductance 58 while the other half of the line is terminated in the inductance 59. Thus, since each coil 58 and 59 has an inductance of a value one half that of the coil 73,

each half of the line will be terminated perfectly in a mid-series manner by the coils 58 and 59.

In the prior art when a single brush was used, it was ordinarily made of sufiicient width to connect at times simultaneously to two adjacent studs. When the direction of sound was such as to produce a current node in one coil, the proper setting of the switch would shortcircuit this coil and the line would not be properly terminated.

It will be apparent, however, that with the arrangement of the present invention, the C-line may be given perfect mid-series terminations.

Position b shows a transient position of the switch in which the line terminations are being changed from those in position a to those in position 0. In position 0 the brush 25 contacts with the stud 34 while the brushes 62 and 83 are not connected to the line. The inductances 58 and 59 are therefore inoperative when the switch is in this position and both theleft and the right parts of the line'have amid-shunt termination. The position d again shows a transient position of the brushes while position e is similar one section advanced to the right.

In practice it is often convenient to use brushes and contact studs which have a considerable width; If this is the case it is necessary to have a certain relationship between the width and the spacing of the brushes with respect to the width and spacing of the contact studs. The proper width and spacing of the brushes with respect to the width and spacing of the contact studs will be apparent from a consideration of Fig. 2. Each of the three brushes 62,10 and 63 has the same width b while the distance between them isthe same as the width S of each of the studs 3| to 36'. Then if we let P be the distance be-. tween centers of adjacent studs and B be the total distance spanned by the three brushes, the following relations will hold:

b=0.5 P-S and 3:15 P-S It will be noted that the dimensions of the development of the switch as shown in Fig. 2 agree with the above formulas. The specific example shown, however, is a particularly convenient one inasmuch as the width of the brushes b is made equal to the width S of the studs. It will be observed, however, that-any desired choice can be made of either b or S and that such choice will determine the value of the other dimensions.

Fig. 3 shows schematically an alternative manner of connecting. the hydrophones and telephones to the retardation'lines from that shown in Fig. 1. In theembodiment described in Fig. 1 the C-lines are shown as feeding to the center of the B-line through the brushes 53, 51' and 46 while the telephones are connected to the ends of the Bline. It will be obvious, however, that the opposite system may be employed if desired. This is shown in Fig. 3. In this figure the C-lines feed to the ends of the B-line and the telephones are connected to the center of the B-line through the brushes 43, 57 and M.- An important difference between the two is that with the latter arrangement the two C-lines must have'separate com-- On the other hand, if separate commons binaural method or by the minimum perceptible difference in the maximum method of observation, and the spacing of the hydrophones. Usually the size of a section is approximately 1.8 waterinches. In the present case I may use a section having about 3 water inches retardation and may also use the same size section for the C-line. In the present invention the 13-, C- and F-lines have the same cutofi frequency and have their. impedances rather well matched and absolutely matched under the same conditions of termination of the B- and C -lines.

When the compensator is used for the maxi-- mum method the switch I0 must be closed. This switch connects the secondaries of the transformer 68 and 69 in parallel for the maximum method. The primaries of the transformers 68 and 68 are matched to the line. The transformers maybe omitted if it is desired only to use the binaural method or if, as above described, the C-lines have separate commons.

While the invention has been described above as applied to a' compensator for use in systems for finding the direction of a source .of sound waves, it will be apparent that it has other applications. Furthermore, it is useful not only in connection with retardation lines having series inductances and shunt capacitances, but also with other types of artificial lines or series -of electrical structures. It should be noted that the line may be composed of impedances in any form including,

mutual inductance if desired and that the bridging elements may be impedances of any suitable form. The bridging elements and a switch of any of the types described may, for example, be used with a lattice line or with a line having series capacitances and shunt inductances.

Accordingly, it will be appreciated that the present invention can be embodied in other forms and therefore I do not desire to limit myself to the embodiment herein described, but I claim:

1. An electric compensator including an artificial line comprising inductive series elements each having an inductance of L and capacitive shunt elements forming sections of the line, switching means for adjusting the length of the line and adapted to place two series connected inductance elements each having an inductance of taining a series impedance element having only two terminals with means for efiectively connecting to the electrical center .of one of said impedance elements including a pair of series connected impedances each having one half the impedance of said series impedance elements and being adapted together to be connected inparallel with one of said series impedance elements and means for transferring electric energy to the common terminal of said series connected lmpedances.

' 3. In an electric compensator including series and shunt impedance elements forming s ti of an artificial line, switching means for varying studs, the widths and spacing of the brushes being so adjusted with respect to the width of the studs that the width of each brush is 0.5 P--S and the total span of the three brushes is 1.5 P-S where P is the distance between centers of adjacent studs and S is the width of each stud.

4. The combination of an electric retardation line having a series of recurrent sections each containing a series inductive impedance element, means for feeding electrical energy to the line between an interior section and each end of the line, said section being in such a position that there is a current node in its series impedance element, said means including a switching device having a center tapped impedance element adapted to be connected in parallel with one of said line impedance elements and said center tapped impedance element having an inductance equal to the inductance of said line impedance element.

LAURENCE BATCHELDER.

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