US1593837A - Radio signaling system - Google Patents

Description

July 27 1926.

. G. A. MATHIEU RADIO sicmmne sysmu FiledvMarch 10, 1922 Qwuenboz L PEL G.A.MATH\EU @331 Qbfozmeng Patented July 27, 1926.

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GASTON ADELIN MATHIEU, OF LONDON, ENGLAND, ASSIG-NOR T0 RADIO CORPORA- TION OF AMERICA, A CORPORATION OF DELAWARE.

RADIO SIGNALING SYSTEM.

Application filed March 1-0, 1922, Serial No. 542,536, and in Great Britain March 12, 1921.

According to this invention an oscillatory circuit is coupled either to an oscillatory circuit connected to the grid of the valve or to the anode filament circuit of the valve, the arrai'igement being such that the valve is normally on the point of oscillating but is unable to do so owing to the withdrawal of energy by the first named oscillatory circuit. 0n the occurrence, however, of the small alternating currents to be detected, say, on the arrival of wireless signals, the valve enabled to generate oscillations, but as soon as these. currents cease the valve ceases to oscillate. The currents in the anode circuit of the valve are caused to affect the grid of a rectifying valve which has in its anode circuit a resistance the two ends of which are connected to the grids of two other valves whose filaments are connected to the middle point of this resistance while their anode circuits include the winding of a relay. Gr the currents in the anode circuit of the first valve may be caused to affect one grid of a second valve having two grids and the windings of the relay are then connected one in the anode circuit of this valve and the other in the other grid filament circuit thereof.

The invention is illustrated by the accompanying drawing in which,

1 shows one arrangement conforming to the invention, and,

Fig. 52, shows a modification thereof.

in Fig. 1 A is the circuit in which flow the small currents to be detected. B is an oscillatory circuit coupled thereto and to an os'icillatory circuit C connected to the grid and filament of valve V the anode circuit of which is coupled back to the circuit C so that the valve can generate oscillations. lly adjusting a potentiometer l connected across a biasing battery the suitable point on the characteristic of the valve may be found. For efficient working it is essential that the value of the back coupling should be. just sufficient to start and maintain oscillations in the circuit C. Owing, however, to the withdrawal of energy by the circuit B the valve is normally unable to oscillate. /Vhen, however, energy is supplied to the circuit B from the circuit A on the occurrence of currents in the latter then the valve can oscillate. As soon as the currents in A cease the valve will cease oscillating.

The currents the angel? llcuit of the valve V are led to a rectifying valve V so that a pulsating current flows in the anode circuit of this valve. The alternating component of this current finds an easy passage through a condenser 0 while the direct component causes a difference of potential between the ends of a resistance 1 The ends of this resistance are connected to the grids of two valves V V the filaments of which are connected to the middle of the resistance while in the anode circuits of these two valves are the windings D, D of a relay. The difference of potential at the ends of the resistance ll. causes both a positive increase of the grid potential of V and a negative increase of the grid potential of the valve V This results in an increase in the anode current of V which acts as the marking current, and in a decrease in the anode current of V which acts as the spacing current.

A condenser 0 may be connected across the relay in order to reduce the effects of atmospherics.

If it is desired to have only a marking current in the relay, the valve V and the upper half of the resistance B may be omitted. This arrangement is particularly suit able for dealing with waves of a length below 2000 metres. For very short waves, say, those of a length below 300 metres, the coupling between the anode and grid circuits of the valve V may be capacitative instead of inductive.

Fig. 2 shows an'arrangement in which the circuit B is coupled not to the circuits A and C which are directly coupled but to the anode circuit of the valve V and is connected to the filament and one grid G of a valve V which has two grids, the other grid G being connected. to the winding D of the relay while the winding D is connected to the anode of the valve V. As before, on the occurrence of currents in circuit A pulsating currents will flow in the circuits of the anode and of the grid G of V. The direct component of the current in the anode circuit therefore increases and acts as the marking current while the direct component of the current absorbed by the grid G diminishes and acts as the spacing current. The maximum strength of this spacing eurrent may be controlled by means of a battery E. Condensers c 0 in parallel with the windings of the relay allow the alternating components. of the urrents to p nd.

also serve for the passage of currents due to atmospherics.

Having described my invention, What I claim is:

1. In a relay arrangement, the combination of a source of small alternating currents to be detected, a three electrode valve capable of oscillating when said currents are supplied thereto, and an oscillatory circuit arranged to Withdraw from the valve so much energy that the valve is normally an able to oscillate and a rectifying valve coupled to the output or the first valve and having a resistance in its output circuit and a relay connected across two points or the resistance.

2. In a relay arrangement, the combinaticn of a source of small alternating currents to be detected, a three electrode valve capable of oscillating when said currents are supplied thereto, and an oscillatory circuit arranged to Withdraw from the valve so much energy that the valve is normally unable to oscillate, a rectifying valve coupled to the output of the first valve and having a resistance shunted by a capacity in its output circuit and a relay connected across two points of the resistance.

3. In a relay arrangement, the combination of a source of small alternating currents to be detected, a three electrode valve capable of oscillating when said currents are supplied thereto, and an oscillatory circuit arranged to ithdraw from the valve so much energy that the valve is normally unable to oscillate, a rectifying valve coupled to the output of the lirst valve and having a resistance in its output circuit and a pair of relays each connected to a mid point of the resistance and having the other connections at opposite sides of the mid point.

t. In a signaling system a circuit for the reception of small alternating currents, a three electrode tube capable of starting and maintaining self sustained oscillations and means independent of said first named cir- 'cuit for Withdrawing from said tube suliicient energy to prevent it from generating oscillations in the absence of signaling currents in said first named circuit, said means comprising an oscillatory circuit.

In a signaling system a circuit for the reception oi small alternating currents, a three electrode tube having an input circuit coupled 'to said first name-d circuit and an output circuit rege'neratively coupled to said input circuit said regenerative coupling being adjusted to a value to start and main tain self sustained oscillations in said tube and means independent of said first named circuit for 'i'vi'thdrawing suflicient energy from said tube 'to prevent it from oscillating in the absence of signals in said first named circuit said means comprising an oscillatory circuit coupled to one of said tube circuits.

6. in a signaling system a circuit for the reception of small alternating currents, a three electrode tube having input and output circuits regeneratively coupled, the re generative coupling being adjusted to a value to start and maintain self-sustained oscillations in said tube and an oscillatory circuit inductively coupled to said first named circuit and to said input circuit for absorbing suflicient energy from said tube to prevent it from oscillating in the absence of signals in said first named circuit.

GASTON ADELIN MATHIEU.

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