US2490847A - Electrical delay device - Google Patents

Description

Deals; 1949 A. H. TAYLOR 2,490,847

ELECTRICAL DELAY DEVICE Filed Jan. 22, 1946 A.C.POWER SOURCE 'W I f "r l TQ PLATE TRANS. PRIMARY a n, J x To FILTRANS.

,jwuwvfoo ALBERT H. TAYLOR Patented Dec. 13, 1949 UNITED STATES PATENT OFFICE ELECTRICAL DELAY DEVICE Albert H. Taylor, Prince Georges County, Md. Application January 22, 1946, Serial No. 642,780

4 Claims.

This invention relates to electrical delay devices and has particular reference to electrical delay devices for the protection of electronic tubes by preventing the premature application of high potentials to the tube elements.

An object of the present invention is to provide a device capable of delaying the application of high voltage to electronic tube elements until the filaments of said tubes have warmed up properly.

Another object of the invention is to provide a means whereby the dela in closing two interrelated electrical circuits is' rendered independent of the time elapsed between repetitive cycles of the system.

Still another object of the present invention is to provide a device which can be used for producing a delay between twosequential electrical phenomena the duration of which is closely con trollable in time.

Still further objects of the invention reside in the details of construction wherein is provided, through this invention, a safety device for the introduction of an electrical delay which is unaffected, in respect to time duration produced, by external conditions such as temperature or pressure.

Other and further objects .and features of this invention will be apparent from the following specification and drawing, showing one exemplary embodiment oi the invention in which the drawing is a schematic diagram of the circuit.

In general it may be stated that the invention described herein has, as. aspecificillustrative use, the function of delaying the applicationof' high voltage to the plates of rectifier or transmitter tubes until the filaments of said tubes have warmed up. This delay, in the present invention, is independent-of thetime elapsed since the tube filaments were last turned on. This embodiment of the invention uses a synchronous motor which begins operation at the time the filaments are turned on. 'After'a timed'ependent upon the motor speed and switch contacts, which may be made controllable, a switch driven by the motor closes and permits power to be supplied to the high voltage transformer or to a utilizing agency, either directly orthrough a relay, simultaneously opening the power supply to the motor circuit and causing the motor driven switch to be stopped in such aposition that the high voltage power suppl circuit is closed until such time as either the high voltage switch itself is opened .or the :filamentpuwer switch is opened. When the filament supply is shut down motion of the shaft in March 3, 1883, as 370 0. G. 757) and then turned on again, or if temporary power failure occurs the plate voltage cannot be applied until the motor-driven switch has made another complete revolution.

In the circuit illustrated, alternating current is supplied from an external power source. Switch is a double polesingle throw switch which controls the power supplied to the filament transformer. the filament transformer primary circuit to indicate when power is supplied to this circuit. Connected to one side of the power supply is a synchronous motor 3 which is coupled with respect to its other input terminal both to contact 24 of a rotary switch and to contact [2 of relay 1. The rotatable element 4 of said switch is mechanically linked through shaft H with the synchronous motor 3. The contact element 5 of said rotary switch is caused to rotate by the such a manner that contacts 24, 25, and .26 are engaged successively. The width of rotor 5 is such that contact 25 is made before contact 24 is broken but contact 26 is further away from contact 25 in angular degrees than the width of rotor 5, so that contact 26' is not made until contact 25 is broken. Uponv further rotation, however, the electrical connection of contact 5 with contact 25 is dis:- enga-ged and contact with terminal 26 is made.

From said rotary switch, connections are made in the manner indicated below:

Rotation contact 5 is connected to one line of the power source and to the moving contact- IB of relay 1. Contact 24 is connected with the synchronous motor as described above. Contact 25 is connected with the moving contact 23 of relay'B. Contact. 26 is connected to the juncture between contact I9 of relay 8 and to one terminal of the energizing coil of relay 8.

- Two relays, 1 and 8, each having two armatures, arev utilized in this: circuit. In the deenergized position of. relay 1 movable contact t6 providesv electrical continuity with: contact [2' and movable contact I"! with contact M. In the energized position of said relay, contacts l3 and [5 are provided electrical continuity with movable'contacts l6 and H respectively.

.In a like manner, relay 8 is so constructed that in the de-energized position movable contact 22 provides electrical continuity with contact 18 and movable contact' 23 with contact 20. In the energized position of said relay, contacts l5 and it are provided electrical continuity with movable contacts 22 and. 23 respectively.

Opposite terminals of the windings of relay 1 A pilot light 2 is shunted across and 8 are connected to one side of the power source through a safety door or interlock switch 6.

In addition to the connections enumerated above, a pilot lamp 9 is connected in series with contact l3 and one lead of the output to the plate transformer primary or to any load device. A double pole-single throw switch, I0, is provided in the plate transformer lead as shown in the figure.

Assuming the device to be so constructed, its operation will be as follows:

Upon connection of the invention with power supplies as indicated and with power-consuming means as exemplified by the primary of a filament transformer and the primary of a plate transformer, no power will be supplied to the circuit elements involved until switch I is closed.

This immediately energizes the primary of the filament transformer and turns on pilot light 2. Power is connected to the motor 3 through contacts l2 and [6 of relay 1. Both relays I and 8 are unenergized. It is assumed throughout the following discussion that interlock switch 6 is in the closed position. Through the rotation of contact 5 of rotary switch 4 over contacts 24 and 25, no effect occurs to either relay I or 8. When said moving contact reaches contact 25, however, current flows through the coil of relay 8, and such energizing effect connects contacts 22 and 23 of said relay to contacts 19 and 2|, respectively. As a result, thereof, relay 8 is rendered self-locking and thus remains energized directly on the power source through switch 1 independently of the rotary switch, while rotary switch 4 continues to rotate over such an elapsed time as is deemed necessary, depending upon contact spacing and motor speed. Upon further rotation contact 5 reaches contacts 25 and 25 thereby energizing relay 1 through contacts 23 and 2| of relay 8. Upon the energizing of relay 1 electrical connection is made between contacts I! and I5 of said relay, supplying power through switch which, when closed, furnishes a path for the supply of energy to the primary of the plate transformer. Simultaneously with the closing of the aforementioned relay 1, :power is supplied through contacts l6 and I3 to pilot light 9, indicating that the plate transformer primary circuit has been energized.

If, subsequent to this time, power should be withdrawn from the filament transformer both relays I and 8 would be immediately deenergized. When, subsequently, power was supplied the motor would again require a revolution throughout the remainder of its cycle to such a position that segment must again be in contact consecutively with terminals 26, 24 and 25 as described I heretofore.

It will be apparent to one skilled in the art that my invention is by no means limited to the particular organization shown and described, but that many modifications may be made without departing from the scope of my invention as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. An electrical delay device comprising a source of electrical power, a plurality of output circuits, first switching means operable to connect said source to one of said circuits, and second switching means operable to connect said source to another of said circuits after operation of said first switching means, said second switching means including a pair of relays, a rotating multicontact switch means for energizing said relays in predetermined time sequence and means operating said rotating multicontact switch means in response to operation of said first switching means.

2. An electrical delay switching means com- :prising a source of electrical power, a plurality of output circuits, first switching means operable to connect said source to one of said circuits, and second switching means operable to connect said source to another of said circuits, said second switching means including a switching relay, a conditioning relay for said switching relay, a rotary switching device for energizing said relays in predetermined time sequence, means initiating operation of said rotary switching device in accordance with operation of said first switching means, and means-terminating operation of said rotary switching device in response to energization of said switching relay.

3. In combination, a source of power, a :plurality of output circuits, switch means operable to form a connection between said source and one of said output circuits, relay operated switch means operable upon energization to form a connection between said source and another of said circuits, relay means for conditioning said relay operated switch means to be energized, a motor driven switching device operable upon operation of said switch means for effecting energization of said relay means and for energizing said relay operated switch means a predetermined interval of time following energization of said relay means, and means terminating operation of said motor driven switching device in accordance with energization of said relay operated switch means.

4. An electrical delay device for selectively connecting a source of energy to a plurality of output circuits comprising first switch means operable to connect said source tov one of said circuits, second switch means for establishing a connection between said source and another of said circuits, conditioning means for rendering said second switch means in an operable condition, a timing device for operating said conditioning means and said second switch means in predetermined time sequence, means initiating operation of said timing device in accordance with operation of said first switch means, and means terminating operation of said timing device in accordance with operation of said second switch means.

ALBERT I-I. TAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,731,917 Anderson Oct. 15, 1929 1,893,223 Burkle Jan. 10, 1933 1,997,011 ODonovan Apr. 9, 1935 2,120,787 Lowkrantz June 14, 1938 2,267,606 Goldstine Dec. 23, 1941 FOREIGN PATENTS Number Country Date 423,139 Great Britain Jan. 25, 1935

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