US1905332A

US1905332A - Capacity controlled relay

Info

Publication number: US1905332A
Application number: US305754A
Authority: US
Inventors: Constantin D Barbulesco
Original assignee: PAUL S EDWARDS
Current assignee: PAUL S EDWARDS
Priority date: 1928-09-13
Filing date: 1928-09-13
Publication date: 1933-04-25
Anticipated expiration: 1950-04-25

Description

Filed Sept. 15, 1928 2 Sheets-Sheet l C a fi/emsuzrsca April 25, 1933. c. o. BARBULESCO 1,905,332

CAPACITY CONTROLLED RELAY Filed Sept. 13, 1928 2 Sheets-Sheet 2 Patented Apr. 25, 1933 UNITED STATES OONSTANTIN D. BARBULESCO, OF

DAYTON, OHIO, ASSIGNOR TO PAUL S. EDWARDS, OF

DAYTON, OHIO CAPACITY CONTROLLED RELAY Application filed September.13, 1928. Serial No. 805,754.

(GRANTED UNDER THE ACT E5301! 3, 1883, AS'LMENDED APRIL 30, 1928; 370 0. G. 757) The invention described. herein, if patented, may be manufactured and used by or the tube.

i may be incident to m for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to reactance controlled relays and has reference more particularly to ultra sensitive relays operated by extremely small variations in the reactance of an insulated metallic body associated with electrical circuits having capacitance, inductance and reactance.

- The invention broadly comprehends a three electrode vacuum tube associated with a special electric circuit coupled to a syslem of metallic plates or wire. The ensemble is so adjusted that small variations in the reactance of the plates or wires, forming what is hereafter termed the external circuit produce great variations in the plate current of These variations can control in turn any mechanical device by sending'the plate current through an electro-magnet or other transmitting or indicating devices. The tube is associated with a constant frequency oscillating circuit such as disclosed in applicants copending application, Serial No. 305,7 53, filed September 13, 1928.

An object of this invention is to produce great variations in the plate current of a vacuumtube by very small changes in the capacitance, inductance or reactance of metallic bodies associated with the tube by magnetic, capacity or direct coupling.

Another object of this invention is to produce an ultra sensitive reactance'controlled relay which can be operated by extremely small variations in the reactance of insulated metallic bodies or in associated electrical circuits having capacitance, inductance and reactance.

Still another object of this invention is to produce a remote control device for the operation of mechanical or electrical sequences that is responsive to small variations in the reactance of an associated system of metallic plates or wires.

With these and other'objects in view which improvements, the invention consists in t e parts and combina-- tions to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising my invention may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful application to the particular constructions, which, for the purpose of explanation, have been made the subject of illustration.

In the drawings, in which the same reference numerals designate similar elements throughout:

Figure 1 is a diagram of one practical arrangement of my improved circuit.

Figure 2 is a diagram of a modified form of my improved circuit.

Figure 3 is another modified form of my improved circuit.

Figure 4 is yet another modified form of my improved circuit, and

Figure 5 is a diagram of the resonance curve.

Referring particularly to Figure 1, the numerals 1, 2 and 3 indicate respectively, the plate, grid and filament of an ordinary three electrode vacuum tube. The numeral 4 indicates a low loss coil formed by a few turns of heavy copper wire, while 5 is a variable air condenser of large value. The coil and condenser form an oscillating circuit of very short period of oscillation, and as shown, are connected directly between the plate 1 and the grid 2 of the tube. This oscillating circuit is con led to another oscillating circuit which is o the open type and includes a coupling coil 6 and two metallic plates 7 having great surface. These plates, if desired, can be re laced by a system of wires. It is also possi le to ground one plate.

Numerals

8, 9 and 10 indicate ordinary radio frequency choke coils introduced in the grid, plate and filament. circuits respectively. They maintain the grid and filament at a high frequency potential above the point 0 which can be grounded. The numerals 11 and 12 indicate by-pass condensers having large value, ranging above one-tenth of a microfarad in this combination. The numeral 13 indicates a low tension battery and 14 is a potentiometric arrangement across this battery which neutralizes the plate current in a sensitive meter 15. The numeral 16 indicates the winding of an electro-magnet. 17 is a grid condenser and 18 a grid resistance or grid leak; these two elements being so adjusted that the high frequency oscillations in the low resistance circuit, 4 and 5, are nearly annihilated and the plate current maintained at a very low value. This is due to periodic charges of the condenser 17 and discharges through the resistance, 18.

If the circuit associated with the sensitive plates 7-7 is brought near resonance to the oscillating circuit, 45, the frequency of the low frequency discharges increases and is always followed by an increase in the plate current. It the coupling of these two circuits is too strong the low frequency oscillation stops as soon as the open circuit is brought in resonance; in the same time the plate current jumps to a high value and all the sensitivity is lost.

The optimum coupling of the open and closed circuits can be determined by proper adjustment of the variable condenserfi to a point where the low frequency oscillation is not stopped.

If the coupling is decreased to an optimum value and the capacity 5 varied a resonance curve as shown in Fig. 5 is obtained. The plate current starts from a very low value on account of the biasing efiect of the grid leak, and increases very rapidly when the resonance is approached. When using an ordinary tube, the plate current may be varied from one milliampere to ten milliamperes or more. If we select as an operating point, A1 or A2, which are points of inflection on the resonance curve, it is readily understood that extremely small variations of C will produce great variations in the plate current.

The external circuit, 677, can also be designed in a great multitude of vcombinations in order to adapt it to practical requirements. It can be tuned to a frequency multiple to the natural frequency of the low loss oscillating circuit, 5. The external circuit can also be composed of multiple arrangements coupled to multiple arrangements of the circuit, 4-5.

It is also possible to obtain the same results as are obtained with the circuit shown in Figure 1 by a rearrangement as shown in Figure 2, in which the sensitive system, 6-7, is modifiedto a closed circuit and the system of plates or wires are attached directly to the plate and denser 5.

Either of the circuits indicated above can 'a time interval and grid of the tube replacing the conbe so adjusted that a variation of the order of a micro-microfarad or less in the capacity of the associated system of plates or wires produces a great variation in the plate current of the tube, and so far as I am aware, there is no other existing device having the extreme sensitivity to reactance change which the described circuits possess. It is possible to adapt a device of such senitivity to many practical uses, such as alarm systems, registering and measuring devices, and remote control apparatus for the operation of mechanical and electrical sequences.

The relay 16, as shown, may be connected to the high tension or plate battery. lVith the relay may be associated a signal circuit shown conventionally in Fig. 1 as comprising a signalling device 20 and a pilot lamp 21 electrically coupled to the system.

The sensitivity of the described arrangement will be appreciated when it is considered that the presence of a man approaching the system of wires (or plates) 7 comprising the external part of the circuit, can be detected at a distance of ten feet or more. This indication, as has been explained, is secured by the change in capacity introduced into the system by the approach of an extraneous body. This change in capacity causes sufficient change in the plate current to actuate an indicating instrument as by ringing a hell or operating other equivalent alarm devices.

The exam le given of the indication of the approach 0 a person is merely one of the great numberof practical uses to which the device may be put. With a device of such sensitivity it makes it possible to utilize it for the following pur oses: alarm systems such as burglar, bank, actory and premise protection systems; counting out production items such as registering passage of bodies through an'electrostatic field; warning devices for airplanes to indicate or register their proximity to earth or other obstacles; registering device for indicating the level of liquid or other fluid or movable bodies; detection of impurities or defects in insulating materials; measuring device for gauging the thickness of materials of construction; detecting de-v vice for indicating the presence of foreign metallic substances; a traffic signal for indicating the passage of vehicles at specific points on highways; recording device for counting of people entering theaters, street cars an so' forth; remote control devices for the operation of mechanical or electrical sequences; specific inductive capacity meters;

capacity meters capable of measuring extremely small capaclties; counting'device or meter device for gas or electrical meters; electrical timing of races or other events wherein capacity change occur; railroad signaling; time interval enunciating or recordin systems. In other words, as will be appreciated, the device has an extremely wide range of applicability and may be utilized effectively, as stated, wherever a change in reactance is introduced into the external system.

The operation of the device will be appreciated from the foregoing description. When the device is in operation the grid blocking condenser 17 charges and discharges intermittently at a low frequency. The

coils

8, 9 and 10 are so designed that they produce across the tank circuit, composed of the large capacity 5 and small inductance 4, a driving electromotive force of very high frequency. The condensers 11 and 12, being bypass condensers of large value, will not oppose the free passa e of the high frequency oscillation. The p ate element of the tube therefore is maintained, together with the batteries 13 and 19, at ground potential, as shown in the drawings. he potentiometric device 14 bucks the plate current flowing from the negative side of the low potential or filament battery 13 toward the negative side of the high tension or plate battery 19. This then permits the adjustment of the position of the needle of the galvanometer to any desired position of the scale so that the variations in plate current may be read rather than its absolute value.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

I claim:

. 1. In combination, a self-modulated high frequency oscillator of the electron. tube type comprising a vacuum tube having a filament,

grid and plate, a tank circuit comprising a low inductance, large capacitance and ow losses connected across the grid and date, a coil between the filament and the gri and a second coil between the filament and plate of the tube.

2. An electrical indicating system comprising an electronic tube oscillator producing high frequency oscillations modulated at radio frequency, a tank circuit com )rising a low loss coil and condenser connected between the plate and grid of the tube, and an open oscillating circuit inductivity coupled to the tank circuit.

3. A high frequenc electronic tube oscillator of the constant requency type, including a grid circuit comprising a condenser and resistance discharging at audible frequency, a tank circuit connected between the grid and the plate, and having small inductance, large capacitance and low losses, and a plate circuit in which the mean value of the plate current is a' function of the reactance of the said tank circuit.

4. A high frequency electronic tube oscillator in which the high frequency oscillations are modulated at audible frequency, a tank circuit of low losses connected between the grid and the plate of the tube, and a plate circuit in which the mean value of the current is dependent upon the values of the modulating frequency and an external oscillating circuit coupled to said tank circuit, and having a natural frequency close to the frequency of high frequency oscillations.

5. A high frequency electronic tube oscillator, in which the high frequency oscillations are modulated at audible frequency, a tank circuit of low losses connected between the grid and the plate, and a plate circuit in which the mean value-of the current is a function of the changes in the reactance of an external oscillating circuit coupled to the tank circuit and tuned to a frequency slightly different from the high frequency of the 0scillator.

6. A high frequency electronic tube oscillator adapted to produce high frequency oscillations modulated at audible frequency, a tank circuit of low losses connected between the grid and the plate of the tube, an external oscillating circuit coupled to the tank circuit and a plate circuit in which the mean plate current under oes large variations when the reactance of't e external circuit is slightly changed.

7 A high frequency electronic tube oscillator adapted to produce high frequency oscillations modulated at audible frequency a tank circuit of low losses connected between the grid and the plate of the tube, an external oscillating circuit coupled to the tank circuit, a plate circuit in which the mean value of the current is a function of the natural frequency of the external circuit whentuned close to resonance to said tank circuit.

8. A high frequency electronic tube oscillator producing high frequency oscillations modulated at audible frequency, a tankcircuit of low losses connected between the grid and the plate of the tube, an external oscillating circuit coupled to the tank circuit, a plate circuit including an indicating device showing the variations in the mean value of the plate current as a function of the variations of reactance of the external circuit.

9. A high frequency oscillator of the electronic tube type producing hi h frequency oscillations modulated ataudible frequency, a tank circuit of low losses connected between the rid and the plate of the tube, an external osci lating circuit coupled to the tank circuit, a plate circuit includin a signal device to indicate the presence 0 a foreign body approaching the external circuit.

10. A device comprising a high frequency oscillator of the electronic tube type adapted to produce high frequency oscillations modulated at audible frequency, a tank circiut of low losses connected thereto, an externalcircuit coupled to the tank circuit, and a plate circuit including signal devices to detect a variation in the position of mass with respect to the device.

11. A device comprising a high frequency oscillator of the electronic tube type producing high frequency oscillations modulating the lower frequency, a tank circuit of low losses connected thereto, an external oscillating circuit coupled to the tank circuit, a plate circuit and measuring devices in the plate cir cuit to indicate the position of mass relative to the device.

12. A device comprising a high frequency oscillator of the electronic tube type, adapted to produce high frequency oscillations modulated at a lower frequency, a tank circuit of low losses connected thereto, an external oscillating circuit coupled to the tank circuit, a plate circuit and measuring devices in the plate circuit adapted to show the effect of the intensity of the stationary electromagnetic field, produced by the reflection of the high frequency wave radiated by the external circuit from a conductive mass.

13. A device comprising a high frequency electronic tube oscillator in which the high frequency is modulated at audible frequency, a tank circuit of low losses connected thereto, a plate circuit, means in the plate circuit adapted to show the variation of the intensity of the stationary electromagnetic field established by a radiating circuit coupled to the tank circuit.

14. An electric device comprising a high frequency oscillator of the electronic tube type. means to modulate the high frequency oscillations at audio frequencies, an open oscillating circuit coupled to said oscillator and tuned to frequency close to the high frequency of the oscillator, and adapted upon variations in its reactance to vary the mean value of the plate current of said oscillator. and an electrically operated signal coupled to the plate circuit.

15. An electric device comprising a high frequency oscillator of the electronic tube type, means to modulate the high frequency oscillations at audio frequencies, an open oscillating circuit coupled to said oscillator and tuned to frequency close to the high frequency of the oscillator, and adapted upon variations in its reactance to vary the mean value of the plate current of said oscillator, and an electric relay conductively coupled to the plate circuit.

16. An electric device comprising a high frequency oscillator of the electronic tube constant frequency type, a high frequency oscillating circuit connected thereto, means associated directly with the tube to modulate the high frequency oscillations at audio frequencies including a blocking condenser and a leak resistance in the grid circuit, means for controlling the mean value of the plate current of said oscillator including an open oscillating circuit tuned to a frequency close to the high frequency of the oscillator coupled to the said high frequency oscillating circuit. and means to indicate the variations in said plate current.

17. An electric device comprising a bi h frequency. oscillator of the electronic tu e constant frequency type, a tank circuit of low losses connected between the grid and the plate of the tube, said circuit including a large capacity and a small inductance, means to modulate the high frequencies at audio frequencies including a blocking con denser and a leak resistance placed in the grid circuit, means for controlling the mean value of the plate current of said tube including an external oscillating circuit coupled to the tank circuit and having a frequency close to the high frequency of the oscillator and means including an indicator in the plate circuit to indicate the value of the plate current.

18. A high frequency electronic tube oscillator in which the high frequency oscillations are modulated at audible frequency, a tank circuit of low loss connected between the grid and the plate of the tube and a plate circuit in which the mean value of the current is dependent upon the values of the modulating frequency.

19. In an electrical circuit, a self-modulated high frequency oscillator of the electronic tube type comprising a filament grid and plate, a tank circuit including a low inductance, large capacitance and low losses connected across the grid and plate, a coil between the filament. and grid, a second coil between the filament and plate, an external circuit comprising capacity, inductance and resistance coupled to the tank circuit, whereby electro-static changes occurring in the coupled circuit produce reactance changes in the tank circuit. and produce a plate current change in the plate circuit of the oscillator.

In testimony whereof I afiix my signature.

CONSTANTIN D. BARBULESCO.

III