Патент USA US2410809код для вставки
Nov. 12, ‘1946. _ s, ._ CORY ' 2,410,809 TELEGRAPH S'IGNAL DISTORTION MEASURING CIRCUIT Filed Dec. 27, 1943 '5 ' //0 M ‘1 go a “ F/G. / rm / 1 ‘5/107 ~I~ ' _STOP L 2/! 2/0 1 sunr/f‘ / I’ 2 I 3 I 4 5 I I STOP A RECTIFYING PEAK VOLTMETER mug/Ton S l CORY A Tram/EV Patented Nov. 12, 1946‘ UNITED STATES 2,410,809 TELEGRAPH SIGNAL DISTORTIGN MEASURING CIRCUIT Samuel 1. Cory, Towaco, N. 55., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application December 27, 1943, Serial No. 515,7 79 6 Claims. (Cl. 178-169) 1 This invention relates to telegraph signal dis tortion measuring circuits and more particular ly to an improved distortion measuring circuit of the high-resistance, distributor-segment type, such as is disclosed in application Serial No. 300,299, W. Y. Lang, ?led October 20, 1939, now Patent No. 2,340,224, granted Jan. 25, 1944. The invention herein represents an improvement over previously known distortion measuring cir cuits of the high-resistance segment type in that the high-resistance distributor segment is ar ' ranged in a potentiometer circuit instead of in a so that when there is no distortion present, that is, change in the duration of a signal element from standard, brush I04 will be equidistant from the ends of the high-resistance segment when a telegraph signal element is received by relay IOI. High-resistance segment I05 may be of any high-resistance material such as carbon or graphite. It may be metallic, including alloys, or non-metallic. It may be an element, chemical compound or mixture. series circuit as formerly and the voltage due to the charge accumulated on the condenser, which - is a measure of the distortion, is compared with a ?xed standard voltage in a manner to provide an accurate indication of the sign and magnitude '2 well understood in the telegraph art. The vdis tributor brush I04 and segment I05 are adjusted As an illustration of a suitable mixture, segments may be formed of a mixture of graphiteand liquid porcelain pressed into the desired form and hardened. 0r mix‘ tures of magnesium oxide or silicon dioxide with materials ‘of higher conductivity, such as carbon of the distortion. or the like, may be employed. The segments may An object of the invention is the improvement also comprise wire of high-resistance wound on a of distortion measuring circuits. 20 suitable core. A more particular object of the invention is Positive battery of a de?nite standard po the improvement of distortion measuring circuits featuring high-resistance distributor segments, tential, regulated within close limits, is connected to the right-hand end of high-resistance segment so as to obtain a more accurate quantitative in I05. The left-hand end of segment I05 is dication of the magnitude of the distortion in a 25 grounded. As thus arranged, segment I05 and its telegraph signal. . traversing contacting brush I04 form a potenti A feature of this invention is a high-resistance ometer. segment on a telegraph signal distributor con When the armature of relay IOI engages con nected in a manner so as to form with its tra versing contact a variable potentiometer. These and other features will become apparent from reference ‘to the following description when read with reference ‘to the associated drawing in which: ~Fig. -1 is a circuit schematic showing the inven tion in simpli?ed form; and ' tact I 02 a circuit extends from some point on the potentiometer, depending upon the position of brush I04 at the instant, through contact I02 to the right-hand terminal of condenser I06, the left-hand terminal of which is grounded. Con denser I 06 is of small capacity. When contact E02 is closed, condenser I00 is charged to a po tential dependent upon the position of brush I04 Fig. '2 is a circuit schematic showing ‘the in on segment I05. vention in more detail. When there is no distortion present, brush I04 Refer now to Fig. 1. will be equidistant the ends of segment I05 when Incoming telegraph signal impulses are re 40 the incoming signal-element is received and con ceived ‘through conductor I05 which is assumed tact 1-02 is opened. Under such'condit'ion the to be connected at the left to a telegraph circuit potential applied to condenser I06 will be one incoming from a distant ltelegrap'h station. In half that of battery I07. When contact I03 is response to vthe incoming signals, the armature of closed the right-hand terminal of condenser I06 is relay I 0| is actuated to engage either contact connected through the armature of relay I0 I, con I02 or contact I03 depending on the nature of tact I 03, voltmeter I08 and positive battery 109 to the signal. Traversing brush I00 and ‘high-re ground. The potential of battery I09 is equal ‘sistance segment I05 are parts of a rotary tele to one half the potential of battery I01. Under graph distributor. The rotary telegraph dis this condition there will be no de?ection of the tributor per .se is well known in the telegraph 50 meter needle from its center zero position. If, art. ‘The-segment I05 physically is a segment of however, the brush I04 is not equidistant the an annular ring. A‘brush arm carrying brush ends of segment I05 when the incoming signal 'Ill'41is driven through a clutch by a motor. The is received, the potential applied to condenser I06 clutch is under control of the incoming signals. This apparatus is not shown as its/operation is will di?er ‘from the potential of battery I09. The '31 ill meter needle will be de?ected to one side or the 2,410,809 other, dependent upon whether the brush I04 is 4 plied through brush 2| I, ring 2!", conductor 220 and contact 2l8 to the right-hand terminal of condenser 22l. On the next transition of the armature of relay 2l5 to engage contact 2“), the right-hand terminal of condenser 22l will be the signal element is longer or shorter than a connected through contact 2l9, voltmeter 222, signal element of standard duration and the primary winding of transformer 223 of the recti magnitude of the de?ection will indicate the fying peak voltmeter 232, which is well known magnitude of the distortion. With a proper in the art, and through positive battery 224 to choice of apparatus elements an accurate indi ground. The potential of battery 224 is ?xed cation of the magnitude of the distortion can be at one half the potential of battery 208. When obtained. the transition between the start signal element The current-time graph H0 shows the pattern and the ?rst signal element occurs at precisely of portions of two consecutive signal elements the proper instant, brush 2l2 will be equidistant and the transition between them. The transi the ends of segment 202 and the potential ap 15 tion, if there is no distortion present, will occur plied to condenser 22!, which is of small capacity, when brush IE4 is equidistant the ends of seg will be the same as the potential of battery 2.241. ment I05. If distortion is present the transition, When contact 2 i9 is later closed there will be no indicated by the vertical line between the cur pulse through the primary of transformer 223. rent and no-current signal elements, will be dis 20 As the position of brush 212 varies from mid placed to the left or right. position on segment 202, a potential which will Refer now to Fig. 2. Fig. 2 is arranged to be greater or less than the potential of battery measure and indicate the sign and magnitude of 224 in corresponding amount will be applied to the distortion in start-stop Baudot code signals. the upper terminal of the primary of transformer In Fig. 2 the solid annular conducting ring 20! and the segmented annular ring comprising high 25 223 and a positive or negative pulse equal to the difference between the potentials applied to the resistance segments 202 to 201 are shown con top terminal of the primary 0f the transformer yentionally as developed. Positive battery 208 223 and the potential of battery 224 will result. is connected to the right-hand end of each of The pulses will be recti?ed in the recti?er circuit the segments and ground 209 is connected to the left-hand end of each of the segments. Rotat 30 comprising the oppositely poled recti?ers 225 and 23! connected to the secondary of trans able arm 2H1 sweeps over the face of the dis former 223 and applied between the grid of tube tributorfrom left to right. Secured to arm 2m 226 and ground and the left-hand terminal of are two interconnected brushes, 2H, which en condenser 22‘! and ground in parallel. Current gages ring 2M, and M2 which engages high 35 proportional to the voltage pulses will ?ow from resistance segments 202 to 201 in sequence. on one side or the other of its midposition on the segment. The direction of de?ection will indi cate the sign of the distortion, that is, whether Rotatable arm 2H] is arrested between each grounded positive battery 229 through ammeter 228 and tube 226 to ground. With miscellaneous telegraph signals from commercial circuits the transition points in the characters will be shifted of the ?rst pulse of a train known as the'start 40 from their normal positions by varying amounts. Under this condition meter 222 will indicate the pulse. The mechanism which performs this sign and magnitude of the average distortion function, as mentioned above, is not shown as it and meter 228 will indicate the magnitude of is well known in the art. High-resistance seg the peak or maximum distortion. After an ob ment 202 is secured in position such that it ex tends equidistant each side of the position on 45 servation, the charge on condenser 221 may be removed and meter 228 caused to indicate zero solid ring 20! which marks the transition between by operating “reset” key 230 momentarily. the start signal element and the ?rst character Attention is called to the fact that the upper forming signal element of each signal train when contact of relay 2l5 and the lower contact of the transition occurs at precisely the proper instant. Similarly, high-resistance segments 203 50 relay 2“! are connected in parallel to conductor 220. If it is assumed that the armatures of the to 201 straddle the transition points between the relays are actuated to engage their upper contacts succeeding signal elements I and 2, 2 and 3, 3 in response to a marking signal element and to and 4, 4 and 5, and 5 and stop. There is no engage their lower contacts for spacing, con high-resistance segment corresponding to the transition between the stop and start signal ele 55 denser 22I will be connected to the distributor on marking signal elements and condenser 230 on ment as the stop signal element terminates when spacing signal elements. Further, each of these arm 210 is arrested in the stop position and the two condensers will be connected to the rectify start signal element controls the release of arm ing peak voltmeter when the other is connected 2W. 2 The transition between the stop and start sig 60 to the distributor. The operation of the circuit per Fig. 2 on nal elements represents the start of each train transitions between the other signal elements of signals and serves therefore as a ?xed refer corresponds to that described for the transition ence point. between the start signal element and signal ele , Brush 2 I0 is not shown in its stop position but is approximately at the transition point between 65 ment I. ‘What is claimed is: the start signal element and the ?rst signal 1. In a telegraph system, a telegraph signal dis element. tortion measuring circuit comprising a variable Signals incoming over conductor 2I3 control potentiometer including a high resistance ele the armature of relays 2l4 and 215, moving them upward to engage their respective contacts 70 ment, a displaceable contact engaging said ele ment, means for displacing said contact along 2H; and 2H! and downward to engage their said element from a ?xed reference in proportion respective contacts 2 I‘! and .2l9 in unison. to variations in the durations of telegraph signal With the circuit in the condition shown a impulses, means for charging a condenser through positive potential of a magnitude depending upon the position of brush M2 on segment 202. is ap 75 said potentiometer and said contact'continuously successive train of start-stop Baudot code signals in a particular position known as the stop posi tion. It is released in response to the reception 5 2,410,809 6 during an interval while said contact is being dis comprising a segment of high resistance and a ro placeduniformly along said element and means tatable contact engaging said segment, a con for controlling the initiation and termination of denser charging circuit including said potenti said charging in response to received telegraph ometer extending through a contact on a tele signal elements. 5 graph receiving relay, means responsive to the 2. In a telegraph system, a telegraph signal dis reception of a telegraph signal by said relay for tortion measuring circuit comprising a high re controlling the charging of said condenser, and sistance variable potentiometer, a contact engag ing a high resistance segment on said poten means for determining distortion in a received telegraph signal dependent on the magnitude of tiometer, means for displacing said contact, from 10 the charge on said condenser. a reference position, uniformly along said segment 5. In a telegraph signal distortion measuring continuously during an interval corresponding to circuit, a variable potentiometerhaving a displace the variation in duration of a received signal ele able contact, means for positioning said contact ment from a signal element of standard duration, in a ?rst position at the instant a transition in a and means for comparing the output potential of 15 distortionless signal element occurs so that the said potentiometer with a ?xed potential in re~ potential impressed through said contact on a sponse to a, received telegraph signal to indicate connected circuit equals a standard potential, and the sign and magnitude of distortion of said sig means for comparing variations from said stand nal. ard potential due to the uniform displacement of 3. In a telegraph system, an automatically var 20 said contact from said ?rst position continuously iable potentiometer connected through a contact during the interval While a distorted signal is be on a telegraph signal receiving relay to a con ing received to measure the distortion in said sig denser, said potentiometer comprising a high re nal. sistance segment and a displaceable contact ar 6. In a telegraph signal distortion measuring ranged to continuously traverse a portion of said circuit, means for varying a potential impressed segment uniformly while a telegraph signal ele on a circuit in proportion to changes in duration ment is being received, means dependent on the of a signal element from signals of standard du termination of said signal element by said relay ration, said means comprising a rotary distributor for determining the magnitude of the potential having a potentiometer thereon, said potentiom impressed through said potentiometer on said 30 eter including a rotatable contact engaging a high condenser and means for comparing the poten resistance segment and means for comparing said tial impressed on said condenser with a ?xed varying potential with a standard potential to in standard potential to indicate the magnitude and dicate the sign and magnitude of the changes in sign of distortion in said signal element. the duration of said signal. 4. In a telegraph system, a rotary distributor, 35 a high resistance variable potentiometer thereon SAMUEL I. CORY.