US1185711A - Receiver for wireless telegraphy and telephony. - Google Patents

Description

G. W. PICKARD.

RECEIVER FOR WIRELESS TELEGRAPHY AND TELEPHONY.

APPLICATION FILED MAR.9.1910.

Paen'odune 6, 1916 Mara? (gru i vu EENLEF VHITTXEB PIQKRD, OF AMESBURY, MASSACHUSETTS, ASSG' a- EFE@ WRELESS SPECILTY PIPABATUS COMPANY, 0F NEW YORK, N. Y.. CQ-,

TIQN QF NEW YORK To all 'ze/5,0m t may concern.'

it lreoivn' that I, GRuENLri/ir TW. Piou- Aiui, a citizen'of the United States of einer ica, and a resident of Amesbury, Massachusette, have invented certain iieiY and useful liiiproveuients in Receivers for llfireless Te# f legraphy and Telephony, the principles of ivliicl. are set forth in the following speci iication and accompanying drawings, which disclose the form of the inventionwhicli now consider to be the best of the various forms in .which the principles of the invention may be embodied. Y

This inventioii relates to ineens, for re" tric Waves.

"lie object oi the invention is to provide commercially useful means for translating i the energy of minute high frecuency oscillations or alternating electric currents'iiito a forni capable of efficiently actuating an indieating mechanism.

lliave previously shown (l`he measuremerit o'received energy et'ryireless stations, Elecri'cal Review, December ith, i906; Solid rectiiiers, Electric@ Ire/view, Februery 20th, 1999) that the minuteoscilletcry currents in the receiving circuits of a wire-- less telegraph or telephone station are' of sufiicient energy to directly actuate a sensitive y indicating mechanism, such as a telephone receiver, if only this energy be converted into a "form (i. e., direct current) suitable for operating-the indicating mechanism. The

truth of tnis statement has been amply demonstrated bythe successful commercial use.

ci several forms of my detector, the solid rectifier detector, in which, by means of rectication,tlie received oscillations are con verted into a direct current form capable oi y operating the indicating mechanism. i y

in my improved forni of receiving circuit, rectification is no longer used as a means of transformation, the received oscillations lieiug converted into direct curi-ent by means ci an abrupt change in the character or con stents of the receiving circuit during the receipt of oscillations.

- 0f the accompanying drawiiigs,'i4`igiire l; 'is a diagrammatic illustration of a Wireless telegraphy or telephony receiviiigl station in which the invention is embodied. 2 "is a modied form of the investiert Secicatien of Letters Patent.

ceiviiig iritelligeucev communicated by elec-v Ainductan'ce L, this st ln Fig. l the aerial conductor, or antenna, A, is connected to earth, Gr, through an inductaiice L, which should'be 'variable to permit of tuningn In shunt around this inductaxiceL is connected the indicating mechanism or signabproducing device such. as a inductaiice li arid telephone R are sliuuted intermittently and abruptly by the vibrator. 'in operation, Fig. 1, the passing trains of electric Waves set up electric current oscillations iii the tuned circuit A, L, G. This circuit, containing' both inductance and capacity, is a resonant circuit, 'and the energy therein .alternates i'roiri the static to the kinetic form, being' alternately inthe shape of an electrostatic field around the antenna A, and oil a magnetic field iii and around the inductaiice L.. At definite intervalathere 'ore,"the received energy is stored in the magnetic eld or' the inductance L. lf at such time the telephone receiver R is abruptly connected, cy the operation of T, around the Jd energy is prevented from swinging bach of the circuit, (such as the capacity of the wire oil antenna A), but. instead, as the magnetic ifield collapses, is ydischarggjed through the telephone receiver, bausing the .produc tion ci' a cliclr or sound.l The rate at which a given discharge taires place is, of course, entirely governed by the resistance and iiiductance of the telephone receiver R, and the inductance L, and not et all by the 'requericy of the oscillations iu the resonant circuit which produce the lield about L. rllie discharge is therefore such as to effectively operate the telephone receiver R. The acn `tion of 'T is in :eect to 'cut out. the induc- .teiice L from 'tlie'resoiiant-eircuit in lwhich the oscillatious Were-produced, and preferably at e time rilieii lilies the maximum" Patented Furie d, luid. l Application cd .'xzarci 9, 1910. Serial No. 548,130.

to the capacity element amount of energy about it in the forxnof its magnetic iield; and the claims hereof are intended to include just this action, to the end' oit discharging the energy through R. The eect of connecting R in shunt to L is to cause the energy of the field to produce a pulse of cent which passes through B. This is a direct current pulse and therefore highly eiicient in operatingthe telephone receiver. The compulsion of the current through the telephone circuit permanently removes this energy from the resonant circuit, but the inductance L is connected in 'the l resonant circuit ready to be again charged by the csciilations of energy therein newly received from additional ether Waves. in brief, starting with an inductance coil in a suitable or known oscillation circuit, the invention includes such combination therewith of an interrupter (i. e., intermittentlyactiug device) and a direct-current signal-producing instrument such as a telephone and of low resistance, as will cause the operation of the signal-producerby the pulse of current caused by the collapse of the magnetic tioid about the inductance. This i. a coniplished by the action of the interrupter in connecting together the inductance andA signal-producer at a time when the energy yet exists in kinetic form in the iield the inductance, and before` such enn has reverted to the static form iu the capacity element of the oscillation cil-cuit so that the current pulse produced by the re* suitiug ccilapse ot' the field conveys the energy which was stored in the field over to the low resistance and therefore eliicient signal-producer instead of permitting' such energy to revert to the vstatic form in the capacity element of the oscillation circuit.

'1W hile the invention is operative with spark sending, it is not so well adapted for that as for undainped wave sending, on ac count of the di'liculty in shunting L by at iicient strength of field about L to the eiieient amount ci' ennipir-.g oscillations Wave iovvever, undarnped Waves are ig, all that is necessary is that operated during the receipt of a 'wav as `in Wireless telegraphy, or a continuous train of varying Waves as i' t.. eiess telephony, Witiout especial nce to the rate of T relative to the x p. `ivave-train or trains. Jalso the energy .field ot L is eliciently tapped into at co'nparativeiy lov! rates of vibra 'i n "it", because action not only occursivhen El actualy makes contact, but continues through the minute spark across the o 'i when they are separated-by a c distance oL a fraction of a micron. The operation of T for telegraphic use at a rate oniy a ien' times greater than the operation possesses the great advanta of the sending key produces very good ren Lieavir sults in telephone Qd, and even i of the invention, Withoutany vibrator at ali,

butsiniply by the manual operation of a key in the place of T. 0f course, the use of the invention does not cause the diversion of all the energy of the field ot lli to R, be cause a large amount of it is shut oil frei-u R when the contacts of if are wide apart; but the action is very edi/cient as compared with the best detectors, and the invention ge over use under s.,

.,rwhen of detectors in that.I and interference.. i vibratory maireu operated in any ay ing niake-and-breair devices.

Vhen it is not desired or is inconvenient to employ the auxiliary energy, required to operate T when it consists oit a vibrating n1ake-and-break device, T consists of a device having no parts required to be moved, such as a finely-adjustable minute sparkgap, or a microphonic contact. Any such f device may be used in the circuit of either Fig. l or Fig. 2, being operated by the rise of potential across its terminals to cause the effective shunting of R around L. li? a inicrophonic conta-ct be used, instead ofi the sparlrgap, then a preferable form is. one of the various welldrnown selt-restoririgj deW vices, so that the telephone it is automatically cle-shunted from inductance L, the device then being, like the vibrator or minute spark-gap, an' intermittently-acting device.

The device T may be used with any form of antenna, including my magnetic loop an tenna of Letters Patent No. 876,996. ln that specific case the inductance of the ioop itself acts as the inductance L hereof. 'in factin any case the inductance need not be in the fornil of a Winding, although that form will generally be preferred. v

The ordinary present-day telephone receiver is believed to be at the present time the best device for use at R. But it should be of low resistance, and the one E have successfully in the invention had a resi tance of only one ohm.

As above suggested, this invention possesses the great advantage that the device T,

The modified circuit shown in Fig. 2 opv crates in almost exactly the manner s that of Fig'. l. Here, however, the receiver B; is normally a part et the sci tion circuit fa, L, R, Gr, out ciosure ci? T throws the inductance L, the telephone r eceiver R, and T in series, justas with the circuit shown in Fig. l, and the discharge of the inductance takes place in the. same inanner, and WithA the same resultfif'. e.,'a click or sound from the telephone receiver. Thus "llo far in my use of the invention, this modifilcation of Fig. 2 produces better results than that of Fig. 1.

I claim:

l. The method of receiving intelligence by electric waves, which consists in storing the energy of the Ware-generated oscillations around an inductance in the form of a magnetic field. and then discharging said stored energy in the form of a pulse of current, through a signal-producing device, by abruptly closing a circuit including said device and inductance.

2. The. method of receiving intelligence transmitted by electric waves, which consists in intermittently causing. first, the establishment ot' a magnetic field about an ingluctancc by the passage ot' oscillating currents generated by said waves, and second, the passage through a direct current signal producing instrument, ot' a pulse of direct current generated vby the collapse of said magnetic field.

3. Means for receiving intelligence communicated hy electric waves, which consists of an inductance; a direct current signal producing instrument; and means for intermittently causing, first, the establishment of a magnetic field about the inductance by the passage of oscillating currents generated by said waves, and second, the passage through said signal-producing instrument, of a pulse of direct current generated by the collapse of the magnetic field about said inductance. l'

Je. Means for receiving intelligence communicated by electric waves, which consists of an inductance; a direct current signal producing instrument, included in an oscillating current circuit in series with said inductance; and means for intermittently causing, first, the establishment of a magnetic field about the inductance by the passage of oscillating currents generated by Said waves, and second, the passage through said Vsignal-preducing instrument, of a pulse of direct current generatedby the collapse of the magnetic field about said inductance.

5. Electric wave receiving apparatus which comprises an inductance, a telephone receirer, and an interrupter, connected in series with each other, the interrupter being arranged to intermittently connect the telephone receiver in circuit with the inductance and thereby operate the telephone receiver by the pulse of current from the collapse of the field about the inductance.

1'. Elect-ric wave receiving apparatus which comprises an inductance and a telephone receirer connected in `series with each other in an oscillating circuit, and an interrupter connected around them both and arranged to eii'ectively connect the telephone receiver in shunt to the inductance and thereby operate the telephone receiver bythe pulse of the current from the `collapse of the field about the inductance.v

7; Electric wave receiving apparatus, which comprises an inductance, a low resistance direet-current signal-producing instrument, and an interrupter acting to shunt through the signal-producing instrument the pulse of current produced by the collapse'of the magnetic field about the inductance.

8. Electric wave receiving apparatus, which comprises an inductance device in a circuit including capacity, a signal-producing device, and means for intermittently disconnecting the signal-producing device Jfrom the inductance and connecting it therewith when energy exists in a magnetic field about the inductance.

9. Means for receiving intelligence comvmunicated by electric waves, which consists of an inductance coil and a signal-producing instrument both permanently connected together in a circuit in which oscillations are setup by the signaling waves; and means for intermittently closing a circuit other than said ose-llatinvl circuit but which also contains said coil and instrument.

GREENLEAF WHITTIER PICKARD.

Witnesses:

EDWARD H. RowELL, MYRA S. ROWELL.

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