US2297668A

US2297668A - Electric compensator

Info

Publication number: US2297668A
Application number: US368655A
Authority: US
Inventors: Batchelder Laurence
Original assignee: Submarine Signal Co
Current assignee: Submarine Signal Co
Priority date: 1940-12-05
Filing date: 1940-12-05
Publication date: 1942-09-29
Anticipated expiration: 1959-09-29

Description

p 9, 1942. L. BATCHELDER 2,297,668

ELECTRIC COMPENSATOR Original Filed 001;. 12, 1939 RETAFDA'HON LINES "T T- INV ENT OR.

ATTORNEY Patented Sept. 29, 1942 2,297,668 ELECTRIC COMPENSATOR Laurence Batchelder, Cambridge, Mass., assignor to Submarine Signal Company, Boston, Mass., a corporation of Maine Refiled for abandoned application Serial No. .7

299,180, October 12, 1939. This application December 5, 1940, Serial No. 368,655

2 Claims.

The present application is a division of my copending application Serial No. 299,180, filed October 12, 1939, now abandoned.

The present invention relates to electric compensators particularly to such as are used for the determination of the direction of submarine sound sources. For this purpose a plurality of electroacoustic transducers for producing eleclrical response upon excitation by compressional waves are mounted at spaced position in a predetermined configuration. A wave impulse arriving from a distant source will, therefore, strike the several transducers or receivers at different instants of time whereby the electrical currents or voltages produced by the said devices will var in time phase depending upon the angle which the direction of the sound source makes with the surface upon which the receivers are mounted. By progressively varying the phases of the several electric impulses so produced in such o. manner as to bring them all into phase, the direction of the sound source can be determined by noting the amount of phase variation required. For this purpose adjustableelectrical retardation lines are commonly employed. The output energy of the retardation lines may be connected to an indicating device such as a pair of telephone receivers so that either a binaural or a maximum efiect is obtained when the compensator is adjusted to bring all the received impulses into the same phase.

It is usually desirable to be able to use a compensator with either the maximum or the binaural method at will. Moreover, when using the maximum method, it is often desirable to insert a high-pass filter in the circuit since a sharper bearing can frequently be obtained by listening to high frequencies only. In order to provide a simple arrangement for switching the compensator from maximum to binaural, with or without the filter and to equalize the energy in the telephones in the three cases, I provide a method selector switch and accompanying circuits as shown schematically in the accompanying drawing.

'The switch itself may be a five-pole, threeposition unit whose control bar is indicated at I. The five poles or movable contacts of the switch are numbered 2 to 6. Each of these makes contact with a set of there stationary studs, A to C for the three switch positions. In position A the telephones are connected to the retardation lines for the maximum method with a filter inserted between the telephones and the retardation lines. In position B the connections are for the maximum method without the filter but with an attenuator in the circuit. Position C is for the binaural method with an attenuator. The filter is schematically indicated at l and left and rightattenuators at 8 and 9 respectively. The retardation lines are indicated at Ill, only the three output terminals being shown. It will be understood that compensation is effected in groups, the energy from the left group of sound receivers appearing between the terminals [3 and I5 and that from the right group of sound receivers appearing between the terminals l4 and IS The telephone receivers are shown at H and I2.

With the switch' in position A as shown, the telephones are connected for operation by the maximum method. The outputs of both ends of the retardation lines are therefore connected together and through the filter to the parallel connected telephone receivers. To this end the loft output terminal l3 of the retardation lines is connected through the brush 4 and its contact A by the lead IE to the input terminal ll of the filter l. The right output terminal ll of the retardation lines likewise, through contact 2 and its stud A. is connected to the input lead I l of the filter. The common terminal l5 of the retardation lines is connected by the lead l8 to the common side of the filter input and to the junction 19 of the two telephones II and I2. The output lead 20 from the filter'is connected to the studs A of the two movable contacts 5 and 6 which are connected respectively to the remaining terminals of the telephones l2 and II.

In position B of the switch in which the movable contacts 2 and 6 are connected to the center studs numbered B, the filter is eliminated from the circuit. If this were done directly, there would be a great increase in the energy actuating the telephone receivers since the filter eliminates considerable amount. In order t- 'reduce the energy in such a manner that the volume of the output ofthe telephones will be the same whether the filter is in or out of the 7 circuit, the attenuators 8 and 9 are provided.

The attenuators 8 and 9 are chosen of such value that they will produce substantially the same volume reduction as that produced by the filter I. For the binaural method one of these is connected in each of the telephone circuits while for the maximum method without filter, they are used in parallel.

Thus, in position B the left terminal l3 of the retardation lines will be connected, through the switch numbered 4 and its contact stud B,

- lead I! and the contact 4 to connect the outputs oi the two parts of the retardation lines in parallel so that maximum rather than binaural response is obtained in the telephones.

For the blnaural method the switches move to position 0, in which case no filter is used, but the output-oi each side oi the retardation lines is separately connected to one of the telephones through one of the attenuators. The circuit is as follows: The left terminal I! through the movable contact 4 and its third position stud is connected by the lead 2| to the input of the attenuator 9 and by the output lead 22 and switch member 8 to the left telephone II. The right terminal 14 of the retardation lines is, on the other hand, connected through contact 2 and its-third position stud to the input lead 23 of attenuator 8 and by the lead 24 to the contact 5 and thence to the right telephone II.

By means of this arrangement the operator canreadily switch from binaural method to maximum method and for the latter cut the filter in 1. In a system for determining the direction 0! a source of compressional waves with the aid of a plurality of spaced receivers and an electric compensator having retardation lines, the combination therewith of a filter, attenuation means, a pair of telephones and switching means for selectively connecting said telephones to said compensator through said attenuation means for binaural listening and for successively switching said telephones for listening by the maximum method with attenuation means without a filter and with a filter without attenuation means.

2. In a system for determining the direction of a source of compressional waves with the aid of a plurality of spaced receivers and an electric compensator having retardation lines, the combination therewith of a pair of telephones, a filter, attenuation means and switching means including means for switching said system from a maximum method with a filter successively to the maximum method with attenuation and the binaural method with attenuation.

LAURENCE BATCHELDER.