US2141286A - Coupling-on or bridging implement - Google Patents

Description

Dec. 27, 1938 R. BARANowsew ZQMLZS@ ,COULING-ON OR BRIDGING IMPLEMENT Filed m. 1, 193e Patented Dec. 27, 1938 UNITED STATES PATENT 'OFFICE Raoul Baranowsky, Berlin-Treptow, Germany,

assignor to General Electric Company, a corporation of New York Application February 1, 1936, Serial No.' 62,003 In Germany February 2, 1935 7 Claims.

In high-frequency telephony across power lines it is frequently necessary to bridge disconnecting places present in said lines, for instance oilor disconnecting switches, in a manner corresponding to the high frequency. For this purpose a coupling condenser is arranged in series with each end of the line, and there is connected to said condenser a coil for compensating the high-frequency reactance of the said con-denser, the two coils serving simultaneously for coupling the two resonant circuits thus established.

That arrangement and combination of the parts stated suffers from the drawback that a change of the wave necessitates a change in the inductance of the coils, and as, as a rule, stationary coils are used for the purpose in view, it is necessary to change the position of the coils in order to change the tuning. Another drawback of said arrangement is that the coupling factor of such inductively coupled circuits is comparatively slight. Besides, every wave length requires a preceding computation of the coil inductance.

This invention presents a coupling or bridging implement which is free from the above-mentioned drawbacks, the gist of the same residing therein that for the highest frequency to be transmitted two resonant circuits coupled and connected in parallel by a capacity are provided, said lcircuits being tuned to said frequency and coupled with one another in such a manner that the coupling means transmits a band of frequencies extending from the above-mentioned highest frequency to the lowest frequency occurring in the respective case. The arrangement according to the invention has thus the character of a multipart filter.

The invention is illustrated diagrammatically and by way of example on the accompanying drawing which shows a bridging arrangement for a high-frequency communication transmitting apparatus across a power-line that can be disconnected by an oil-switch.

In this example L denotes the power-line, O an oil-switch, S1 a high-frequence stopper arranged before said switch, S2 a stopper arranged behind the said switch, R1 denotes the high frequency resistance of the line L on the portion up to the oil-switch, said resistance being assumed to be concentrated, and R2 denotes the resistance behind the said switch. S denotes the high-frequency generator, and E is the high-frequency receiver, both (S and E) being adapted either for sound-transmission or for current-mark transmission or for both. C1 is the coupling-condenser, on which the high-frequency energy is drawn from the line L before the stopper S1. C2 is the coupling condenser, on which the high-frequency energy is re-conducted to the line L behind the stopper S2. Li is a coil for the compensation of the capacitive reactance ofthe coupling-condenser C1. L2 is just such a coil for the coupling-condenser C2, and K denotes an adjustable condenser.

The high-frequency produced by the generator Srpasses across the coupling condenser C1, the coils L1 and Lzcr the tunable condenser K respectively, and the coupling condenser C2 to the receiver E.

It appears from the drawing that the entire arrangement and combination of the parts, across which the high-frequency passes, can be comprehended as a system of two oscillatory circuits connected up in parallel and coupled with one another across the condenser K, the capacity of which can be adjusted. The one of said circuits comprises the generator S, the resistance R1, the coupling condenser C1 and the inductance L1 in combination with the wire connecting said members with one another, and the earth forming the return path. The other oscillatory circuit comprises the high-frequency receiver E, the wave resistance R2, the coupling condenser C2 and the inductanc L2 in combination with the wire connecting these members with one another, and the earth constituting the return path.

Supposing that the two oscillatory circuits are tuned to the highest frequency tobe transmitted, then by appropriate adjustment of the tunable condenser K the coupling means in accordance with the present invention transmits the band of frequencies extending from the aforementioned highest frequency to the lowest frequency to be transmitted. 'Ihat adjustment can obviously be carried out in the simplest way and presents the advantage that it can be effected at any time and especially also at an open line without an eX- change of any parts and without any change of the coil adjustment. Therefore the entire highfrequency system receives by thev coupling as described a band-characteristic, the breadth of which can be varied in a simple manner.

I claim:

1. The combination, in a system for coupling two power lines together for carrier currents having frequencies spaced apart by a desired range of frequencies, of a pair of oscillatory circuits tuned to one of said frequencies, one of said oscillatory circuits comprising the impedance of one of said power lines and the other oscillatory circuit comprising the impedance of the other of said power lines, and a reactance element to couple said oscillatory circuits and to resonate with the reactance of said oscillatory circuits at a frequency spaced from said one frequency by said desired range.

2. The combination, in a system for coupling two power lines together for carrier currents having frequencies spaced apart by a desired range of frequencies, of a pair of oscillatory circuits tuned to one of said frequencies, one of said oscillatory circuits comprising the impedance of one of said power lines and a branch across said line and the other of said oscillatory circuits comprising the impedance of the other of said lines and a branch across said other line, and a reactance element connected between said branches to couple said oscillatory circuits and to resonate with the reactance of said oscillatory circuits at a frequency spaced from said one frequency by said desired range.

3. The combination, in a system for coupling two power lines together for carrier currents having frequencies spaced apart by a desired range, of a band-pass network comprising two oscillatory circuits tuned to the same frequency, each of said oscillatory circuits including a respective one of said power lines, and a reactance element to couple said oscillatory circuits, and to resonate with said oscillatory circuits at a different frequency, said frequencies being spaced apart by said range.

4. In a system for coupling two power lines together for carrier currents having frequencies spaced apart by a desired range, a band-pass network having low attenuation for all currents in said range comprising a series connection across each line, each series connection comprising inductance and a condenser, and a reactance connected between said series connections.

5. In a system for coupling two power lines together for carrier currents having frequencies spacedapart by a desired range, a band-pass network for said carrier currents comprising three condensers connected in series between said power lines, and a pair of inductances, each inductance being connected between ground and a respective point on opposite sides of the intermediate of said condensers.

6. The combination, in a network for transmission of a band of frequencies from a current source to a load, of a pair of oscillatory circuits, one of said circuits comprising an inductance and a condenser connected in series across said source and proportioned to resonate with the impedance of said source at a frequency at one extremity of the frequency range to be transmitted, the other of said circuits comprising an inductance and a condenser connected in series across Said load and `proportioned to resonate with the impedance of said load at said frequency, and a reactance to connect together said oscillatory circuits and to resonate with the reactance of said circuits at a frequency at the opposite extremity of said range whereby said network offers low impedance to currents supplied to said one of said oscillatory circuits having any frequency within said' range.

7. In a system for coupling a source of currents having frequencies extending over a wide range to a load, the combination of a pair of irnpedances, one of said impedances comprising an inductance and acondenser connected in series across said source and proportioned to resonate

Images