US1461790A - Maximum-voltage indicator - Google Patents

Description

M. SULTZER MAXIMUM VOLTAGE INDICATOR Filed May 31, 1919 July 17, 1923. 1,461,790

ATTORNEY Patenteduiy iv, was.

MORTON SULTZER, OF BROOKLYN, NEW YORK, ASSIGNOR TO AMERICAN: TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

MAXIMUM-VOLTAGE INDICATOR.

Application filed. May 31, 1919. Serial No. 301,002.

Toallwhomz'tmayconcern: 1

Be it known that I, MORTON SULTZER, residin at Brooklyn, in the county of Kings and tate of New York, have invented cera tain Improvements in Maximum-Voltage Indicators, of which the following is a specification.

This invention relates to a device'for indicating the presencebf currents in an electrical circuit, and particularly for recording the magnitudes of the voltages producing such currents, when these currents and voltages are of too short duration to be recorded by any of the ordinary types of recording meters.

According. to the well known principles of electric induction, when two electrical circuits are located in close proximity to each other, a change or variation in the amount of current flowing in one of said circuits is apt to produce an electromotive force in the other circuit. Such induced voltages are apt to cause serious disturbances in the apparatus associated with such a circuit. A speci'fic instance illustrating the above would be in the case of a telephone circuit strung along the line of an electrified railroad with ground .return and exposed to the power circuits of such a system. Sudden increases of current in the power circuit due to short circuits or other trouble would induce a voltage between the telephone conductors and ground which might be sufiiciently high to break down protective devices, thus in certain circumstances producing currents in the telephone wires sufficiently high to permanently magnetize iron cores, or cause fires, or seriously disturb or .disarrange other delicate apparatus with which the 40 telephone line was equipped, or cause physical injury to telephone users. Accordingly in order to prevent disturbance and destruction of apparatus associated with acircuit, it is desirable in advance to have information as to the maximum voltages apt to be induced on a circuitso inductively exposed to other electrical circuits. Furthermore,

as the most destructive and injurious of such voltages are of uncertain occurrence, it 60 is not desirable to associate with such a circuit atype of voltage measuring device requiring'constant supervision, while the ordinary types of recording meters. cannot be used because they fail to respond to impulses of duration as short as the duration of these most destructive voltages.

It is a general feature of this invention to provide a device for indicating and recording the voltages induced on an electrical circuit, such a device being capable of being permanently associated with such a circuit and requiring no supervision other than occasional inspection. Other and further fea tures of the invention will be clear from the following description of the operation of the invention. I

The invention consists essentially of a plurality of individual units connected in parallel between the electrical circuit and ground, or, in general, between the two sides of the electrical circuit each unit being adjusted to operate on a difierent and definite voltage, the diiference in operating voltages being obtained by series resistances of different values associated with each unit. The fundamental partsof each unit are relays whichoperate on short current impulses, such as currents induced on the electrical circuit. Associated with each unit and operating whenever the relays of that unit respond are visual and audible signaling means. Accordingly the number of units will operate wheneverra surge of induced current is transmitted over the electrical circuit will serve as a means for measuring the voltage of such a current. I v

The invention may be more clearly understood from the accdmpanying drawing, in which is illustrated a circuit diagram embodying a preferred form of the arrangements of the invention. The line L may represent one side of an electrical circuit exposed inductively to other electrical circuits, and on which it is desired to measure the maximumvoltages induced thereon. For convenience the other side of this circuit may be shown as the ground. A plurality of individual units are shown connected in parallel between the line L and ground by the conductors 1, 2 and 3. While only a specific number of individual units have been illustrated, it is understood that as many units as desired may be similarly associated with the line L. Included in the conductors 1, 2 and 3 are the resistance elements R R R,, which are of different value, as, for purposes of illustration, R might have a resistance of 5000 ohms, R, a

resistance of 10,000 ohms, R, a resistance of lays 5 and6 of each unit, are provided associated with the batteries 12 and 13. It is pointed out that the current in the locking winding of one of the relays of the unit will produce a magneto-motive force in the same direction as that produced by a given current in the operating winding of that relay, while the current in the locking Winding of the other relay will produce a'niagneto motive force in the opposite direction to that due to the current in the operating winding-of that relay. This is so that no matter what may be the direction of the operating current through the operating windings of the relays, the magneto-motive force due to the current through one of the locking windings will always be in the same direction as the magneto-motive force due to the operating current, and hence one of the relays will always become locked up. Vere it not for this feature the direction of the current through the relay wndings, if alternating, might be opposite to that of the direct current transmitted through the locking windings, with the result that opposing fluxes would be setup in the relay cores which would serve to prevent the energizat on and locking up of. said relays. Associated with each of the locking circuits of the units is a condenser such as the con-' denser 21',='for the purpose of completing the locking-up in case the current in the operatmg winding should fall to avalue below that required for operation before the current in the locking winding has reached a value sutficient to lock th relay. At each of the units, and operating when one of the relays of a unit responds, is a signal lamp such as the lamps 9, 10 and 11. The operation of any of the relays of the units will furthermore operate the pilot relay 30 and the buzzer apparatus 31, which provide an audible s1gnal indicating the operation of the apparatus.

The invention may be more fully understood from the following description of its operation:

If a difference in potential due to inductionfrom a neighbormg power circuit exists between the line L and ground current will flow over the followingpath: from the line L, throughresistance R through one of the wmdmgs of relay 5 and through one of the windings of relay 6, to the conductor 4, to

nitude notwithstanding the resistance R the relays 5 and 6 will be operated. Upon the operation of relay 5 the following locking circuit will be closed about the relays 5 and 6 from ground and positive battery 12, conductor 14, upper armature and contact of relay 5, conductors 15 and 16, lower winding of relay 5, conductor 17, lower winding of relay 6, conductor 18, resistance 19, conductor 20, winding of relay 30, to negative battery 13, and ground. As has been for- -merly pointed out, due to the difference in direction of the two locking windings, the closing of this circuit will lock up either the relay 5 or the relay 6; depending upon filament of signal lamp 9, conductor 26,

armature and lower contact of relay 6, con ductor 20, winding of relay 30, to negative battery 13, and ground. If the relay 5 has been locked up in place ofthe relay 6, this last mentioned circuit would have been completed" from the filament of signal lamp 9, over conductor 23, lower armature and contact of relay- 5, over conductor 25 to the conductor 20. The closing of this circuit will operate the signal lamp 9 which will indicate the operation of the unit associated therewith, thereby indicating that the current induced on the line L was of suflicient magnitude to operate this unit. At the same time, the closing of either of the two last I If the voltage induced on the line L was i of sufficient magnitude to overcome a resistance greater than R such, for example, as the resistance R,, the second unit would be operated as well as the first unit. This would be indicated by the operation of the signal lamp 10 associated therewith. If the voltage of the induced current were of still greater magnitude, such that it would overcome not only the resistance R, and the re- I sistance R but also theresistance R the third unit would be operated also. This would be indicated by the operation of signal lamp 11 associated therewith. As the operation of each of the units is substantiallythe same as that already described for the first unit, no further discussion thereof will be given. Accordingly, irom experivaried forms; without departin spirit of theinvention as define J11 the ap mental data a relationship may "be established between the number and resistance of the units operatedand the induced voltage needed .to operate such units, which relations ship. will serve as a means for. measuring such volt'age. It is pointed outthat as many IlllltSfiS' desired may be associated with the appara- 'tus, and that the deviceyis not limited to nerely the three units specificall lllustrated.

, Furthermore, the devlce is not imited use with telephone circuits alone, but is sultable for use with many typesof electrical circuits,

and=while the arrangements-have been herein specifically illustrated in aeform deemed desirable it is understood that they are capable of embodiment in many and widely from the pended claims. 7

, What is claimed is:

j i 1. A voltage indicating device for a transmission line includin a pluralityof resistance elements of di erent valuesconn'ected to said line, individual units connected with' each of said resistance elements, each of said units including two relay means each having an actuating winding responsive to currents transmitted over the line and a locking winding, said locking windings being so related to 'said actuating windings that the to said line, individual units connected with, each of said resistance elements, each of former windings will notmagnetically op-- pose the latter windings of both relays at the same time, and signaling means controlled by either of said relays.-

, 2. A voltage indicating device for a transunission line including a plurality of resistance elements of difierentvalues connected said units including two relay means each having an actuating winding-responsive to currents transmitted over the'line and a locking winding, the locking winding for one ofsaid relays-being so related to its actuating winding to lock up said relay when the current from said line is transmitted through said relays in one direction, the locking winding for the other of said relays being related to its actuating winding to lock up said relay when the currrent from said line is transmitted through said relays in the other direction, and a signaling means operated'loy either of said relays.

3. A voltage indicating device for a transmission linejncluding a plurality of resist ance elements of different values connected to said line, individual units connected with each of said resistance elements, each ofsaid units including two relay means each having an actuating winding responsive to currents transmitted over the line and a locking winding, said locking windings being So related to said actuating windings that the vidual relay units connected in parallel between said line and the ground, each of said units being responsive to potentials of different magnitudes between the line and the ground, signalingn eans individual to and controlled by each unit, and-signaling means common to all ofsaid units and controlled by either one of said units.

5. A voltage indicating device for a' transmission line including a plurality of individual relay units, means for connecting said relay units in parallel with the transmission line, each of said connecting means including a resistance element of different value whereby each of said relay units will be responsive to potentials of different magniq tudes impressed 'on said line, and signaling means common to all of said units and controlledby either one of said units.

' In testimony whereof, I have signed my name to this specification this 28th day of May, 1919.

MoR'roN SULTZER.

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