US2302213A

US2302213A - Electric circuits for lamp regulation

Info

Publication number: US2302213A
Application number: US288781A
Authority: US
Inventors: Jr Willard C Hall
Original assignee: LLOYD O JAMES
Current assignee: LLOYD O JAMES
Priority date: 1939-08-07
Filing date: 1939-08-07
Publication date: 1942-11-17
Anticipated expiration: 1959-11-17

Description

Nov. 17, 1942. w. c. HALL, JR 2,302,213

' ELECTRIC CIRCUITS FOR LAMP REGULATION Filed Aug. 7, 1959 3 Sheets-Sheet l Inn/ENTER Z NILLHRD E-HHLL,tTR-

FTI E1: 3 1

WTTM

NOV. 17, 194-2. w c; HALL, JR 2,302,213

ELECTRIC CIRCUITS FOR LAMP REGULATION FiledAug. 7, 1959 sshe ets-sn ev'z WILLHRQ EHHLL JR.

FITTY.

Nov. 17, 1942.

w. c. HALL, JR 2,302,213

ELECTRIC CIRCUITS FOR LAMP REGULATION Filed Aug. '7, 1939 '3 Sheets-Sheet 3 INVENTUR WILLHRD E.HHLL,1IR-

W HTTY.

, shoclrs encountered in ordinary use.

atente 1?,

ELECTREG ill 3 s roa Willard 0. Hall, .ln, Los

1- --eles, Califl, assignor 2 Claims.

This invention relates to means and methods for regulating and controlling electrical devices and the power factor of the circuit connected thereto. Although the invention has many uses and adaptations when connected with diflerent kinds and types of electrical equipment such as motors, platirg baths, instruments, rectifiers, converters, etc., its principal demand and ad-. vantages is in the regulation and control of lighting devices, particularly for luminous electric discharge tubes which utilize various gases for conduction of electrical energy through the tubes.

Such tubes are commonly known as neon tubes even though the rare neon gas, which provides the familiar red light, is not present in the tube. Other gases such as argon, helium, carbon dioxide, sodium vapor, mercury vapor, etc. and mixtures thereof are also used to pro-= vide other light colors and various shades thereof. There are many kinds and types of low and high pressure vapor tubes which consist of various kinds of glass, colored and clear, to withstand the heat evolved and also mechanical Some of them are coated with a luminescent material to give the efiect desired. This invention, however, is not limited to any specific type of illuminating unit or units, but can be altered and arranged to be effective to improve the operation of any such unit or units whether connected in single units or banks of parallel or/ and series units.

The gas pressure in the tube is of importance since this determines the striking potential and operating voltages to be supplied thereto. The electrical characteristics of the electrodes also have some bearing in the matter, but since they can be accurately predetermined and perfectly designed for any particular lamp, they will not be further considered. The major features for consideration in heated cathode tubes are the gas pressure (or pressures where mixtures of gases ductive reactance at the time the tube is under the influence of the striking voltage, but when the tube is at normal operation, the voltage drops from its relatively high value with a proportionate drop across the condenser with the result that the current lags the voltage but not suriicient to lower the power factor to less than 90%. Such a circuit is iavored by the power supply companies over present vapor tube cir-- cuits. Heretofore, so far as known, no means have been provided to automatically improve the power factor of vapor tube circuits in asafe and simple manner. Such tubes normally operate at a 50%, or less, power factor.

The vapor tube circuit embraced by this invention uses no switching mechanism nor thermostatic devices to accomplish the desired power are employed) and the fact that when the starting voltage drops the current increases. In view of the fact that a relatively high striking voltage must be initially provided, automatic means must be provided to reduce the striking voltage to a minimum operating value in order to maintain the current in the circuit at a reasonable value.

This invention keeps the current constant, provides a leading current at the striking voltage and a power factor of 90% or better during the normal operation of the vapor tube. This is accomplished by connecting in the circuit a condenser having a reactance greater than the infactor results or the improved eficiency of vapor tube circuits. The life of the tubes, operated in accordance with this invention, are materially in= creased because the cathodes thereof are kept at a high emcient heat at all times; this avoids sputtering at the cathodes, and loss of eficiency because of distortion of the desirable sinusoidal voltage and current wave forms. Therefore, the

current in the tube is kept constant, the illumination always at its maximum, and hence its effectiveness 100% from an attractive aspect. In the cold electrode type of tube, conditions of operation, as regards voltage and current, are quite diderent. In this type of tube, current passes by virtue of ionisation by collision of the gas atoms and produces either a negative or positive glow depending upon the gas pressure and the disposition of the electrodes thereof.

This invention, however, is equally applicable to the so-called cold electrode lamps as set forth, merely as an example, in one specific form of applying the invention. Since there are a great variety of illuminating lamps, no attempt is made to apply the invention to every kind of lamp or. other electrical device.

An object of the invention is to provide means and methods for starting and continuously operating electrical devices at a high power factor, and a dependably constant current. Another object is to present an electrical circuit without mechanical moving parts capable of starting and continuously operating luminous vapor tubes at a power factor of or better.

Still another object is to provide means for operating one or more units of high or low pres invention will appear from the accompanying drawings, the subjoined detailed description, the preamble of these specifications and the appended claims.

Applicant is about to illustrate and describe various forms of his invention in order to teach one how to make, use and vend the same, but

it is to be understood that the drawings and description thereof are not to limit the invention in any sense whatsoever, except as limited by the appended claims.

In the drawings:

Fig. 1 shows one form of the invention in plan view.

Fig. 2 shows the same inventive form diagrammatically.

Fig. 3 shows a detailed portion of an electric discharge tube.

Fig. 4 shows a slightly modified form of the invention diagrammatically.

Fig. 5 illustrates diagrammatically another form of the invention.

Fig. 6 is a plan view illustrating the manner in which the coils shown in Fig. 5 are preferably mounted upon the same magnetic core.

Figs. 7 and 8 are another form of the invention shown in plan view and diagrammatically respectively.

In "the preferred form of the invention, as shown in Figs. 1, 2 and 3, the numeral represents an elongated vapor tube having the heated electrodes 2 and 3 at the ends thereof. This tube may be of glass containing a mixture of argon gas and mercury vapor at a relatively low vapor pressure. Since the construction and operation of these tubes are well known, no special details thereof will be given.

The numeral 4 represents a laminated core in the form of a rectangle having a closed metallic pathfor the flux thereof. The core has a laminated midway bridge 5 which has its ends slightly spaced from the core by fiber spacers 6 and 1 which are wedged between the ends of the bridge and the inner sides of the .core as shown.

Mounted upon the core to one side of the bridge is the single coil 8 and a transformer coil 3, the primary being indicated by the reference character l0, and the secondary by the reference character Mounted upon the core on the opposite side of the bridge 5 is a single coil l2, and the auto-transformer coil [3.

From the auto-transformer coil l3, at the proper voltage tap, lead the wires M and I5 which are connected to the opposite ends of the heating element 3 of the tube. ondary coil ll, lead the wires I6 and II, the wire l6 connecting with one side of the heating element 2 and the wire I! connecting with the other side of said heating element, the wire I? also acting as one of the supply mains and is extended by the wire l8 for connection with the city mains of 120 volt, 60 cycle alternating current. Another supply main l9 leads to the primary winding I0, best shown in Fig. 2, from the opposite end of which leads a wire connecting with one end of the coil 8. From the opposite end of the winding of coil 8 leads a wire 2| making connection with one end of the coil I2, the other end of this coil winding is connected to a wire 22 which makes connection with one end of the auto-transformer coil I3. A wire 23, connected to the wire 2|, leads to a set of plates in the condenser 24. From the opposite set of the condenser plates leads a wire 25 which makes connection with the wire l6 as shown.

From the sec- The coil sets on either side of the bridge 5 of the core have equal inductances and are wound giving 120 volts at 60 cycles, the coils upon the iron core 4 are-preferably arranged as shown in Fig. 1. The coil sets on either side of the bridge 5 is wound with #25 B. & S. gauge copper wire, the combined number of turns for each set being about 1980. Since the cathodes 2 and 3 are designed to operate at a potential of 6.2 volts, a-tap at about 80 turns is made on the auto-transformer |3 for heating the element 3 and a secondary winding of 80 turns is utilized in the coil II for th heating of the element 2. At these values, the condenser 24 should have a capacity of about 3 microfarads. Under these conditions, the tube will have a starting voltage of about 220 and an operating voltage of 65. At starting, the drop across the condenser should be- 230 volts and under normal operation of the tube about 90 volts. This drop across the condenser shifts the power factor from a leading value to about 90% or better at a. lagging position. The current remains constant at 0.3 ampere under starting and operating conditions. reading at operating potential is close to 92% where as the starting potential definitely gives a leading power factor reading.

In the form of the invention shown in Fig. 4, the vapor tube is indicated by the numeral 26 which has the usual heated electrodes at its ends; from one of which leads the

wires

21, 28 and from the

other wires

29 and 30. The induction coil pairs are indicated by 3| and 32, one end of the coil 32 acting as an auto-transformer to feed one of the electrodes as indicated by the connection of

wires

29 and 30, and the other induction 'coil 3| has its end connected to the supply main 33. One end of the coil 3| is shown as having a secondary winding 34 which supplies current by the way of Wires 2'! and 28 to the other electrode of the tube.

The supply main 35 is connected to the electrode feeder wire 28 as shown. As explained in the preferred form of the invention, the induction coils 3| and 32 are wound oppositely upon the core to cause opposing flux at the ends of the bridge so that it functions as a regulator. In the jointure of the coils 3| and 32 leads a wire 36 which connects to one end of a choke coil 31. From the other end of the choke coil leads a wire 38 connecting with the condenser 39, the other side of the condenser having a wire 30 connecting with the electrode feeder wire 21.

The only change in this circuit over the one shown in Fig. 2 is the addition of the choke coil 31 in the condenser line and also the condenser 39' across the main feeders. This coil functions to avoid serious kickback voltages from the condenser and hence possible resulting fluctuations in the illumination of the tube.

The circuit including the condenser 39, choke coil 31 and inductance coil 3| is designed for a resonance balance during the normal operation of the tube 26 while its voltage is at a minimum,

The power factor the power factor at 90% and the frequency 60 cycles.

In the form of the invention shown in Figs. and 6, two vapor tubes are operated by a common circuit arrangement. The electric discharge tubes are indicated by th'. numerals M and 42. The induction coil bank of this form of the invention consists of a plurality of

coils

43 and 44 which are wound in opposite directions causing opposing flux in the laminated iron core 45; similar coils 46 and M are mounted on another leg of the core. A magnetic bridge 48 provides the shunt to avoid fiux flow interference as set forth in the foregoing forms of the invention.

The end coils 63 and 41 have secondary windings 49 and 50 for feeding the electrodes 5! and 52 respectively at the ends of tube 42 as shown. The primaries of

coils

43 and 41 are tapped at 53 and 54 to provide auto-transformers for feeding the

electrodes

55 and 56 respectively of the tube 4|. Although the auto-transformer taps are shown as embracing the same number of turns as the secondaries, this need'not necessarily be the case since the electrodes of tube 4! may require a higher voltage than tube 42 because of their lengths or their difierence in design. The wires connecting the coils with their respective electrodes are shown as the primes and double primes of their respective electrodes. v Wire connectors are shown between the various coils, the center connector 51 being joined to the supply main 58 of an alternating current source; the frequency and voltage of which will depend upon the available supply, but since a 60 cycle 120 volt supply is common in this country, such a source is preferred. The other main 59 leads \ia wires 69 and 6| to the middle tap of the secondary coils 49 and 50 respectively and to a side'of the condenser 62 by a wire 63. The other side of the condenser is joined to a wire 64 which makes connection at the point 65 with theconnector between the

coils

46 and 41.

This form of the invention like the other forms shown in Figs. 1 to 4, has all the same advantages and operating characteristics.

The form of the invention shownin Figs. 7

and 8, appertain to the so-called cold electrode.

type of electrical discharge tube which starts operation by virtue of atomic bombardment to effect ionisation of the gas. The resulting glow may be due to either a positive or negative column depending upon the arrangement of the electrodes and the pressure of the confined gas or gases.

In the drawings, the reference character 65 indicates one of the so-called-cold electrode tubes; it being understood, however, that a plurality of such tubes may be connected in series, parallel or series-parallel arrangement, and the invention would be just as effective in giving the desired results.

At one end of the tube 65, is an electrode 66 and at the other end, electrode 61. These electrodes are in the form of a coiled wire, the ends of which have leads which terminate into a single exterior wire; one such wire is indicated by 68 for the electrode 66 and another wire 69 for the electrode 61. Wire 69 is a main as well as the wire ll leading to the coil and they are connected to a source of current of suitable voltage and frequency.

The coil 10' and its component coil 10" comprise a coil 10 having its windings arranged to cause flux to flow in the core 12 in the direction One end of the winding of coil 13' is connected to wire 68 and the other end to coil 13". Coils 10' and 10 are connected in'series also. The

other ends of the coils 10" and'13" are connected by a wire I5 from which leads a 'wire I6 to one side of the condenser 11. A choke coil 18 is inserted between the other side of the condenser and the main 69. A condenserj'lS is provided across the mains.

In the circuit just described, the tube may contain sodium and mercury vapors at a pressure of between 8 and 15 mm. of mercury. The voltage across the mains should be 230 and the frequency 60 cycles. This type of high pressure tube would require a starting line voltage of 230 at 1.8 amps, and an operating line voltage of 230 at 3 amps. to maintain the lamp at maximum illumination of about 440 watts input. The lamp running voltage itself while cold is 65 which rises almost to line voltage when at full illumination. The power factor rises as the tube voltage increases because the drop across the condenser also rises to cause a beneficial increase in capacitive reactance.

During the starting period of the tube, the circuit comprising the coils 10', 10" and I8, and

the condenser TI, is near resonance while the this increases the impedance of the regulator input power is near power factor. As the temperature of the tube rises, there is a greater voltage drop across it and also across the element l0, l0", l1 and '18, thus increasing the inphase flux in coils l0 and 10" with respect to coils l3 and 13" on the same magnetic core;

coils. At start, the tube has an input of 200 watts which rises to 440 watts at full illumination.

Such tubes in the ordinary circuits take 20 minutes to come to full illumination from a cold start whereas with this invention applied, the same tube requires only 15 minutes. Should a break in the current supply occur, the tube with the ordinary circuit would require 10 minutes to re-ignite and a few minutes more to come back to full illumination whereas when this invention circuit is employed, the tube ignites immediately and regains full illumination shortly thereafter. The reason for this advantage in applicants circuit appears to be that the condenser and inductance coils immediately increase the voltage across the tube to substantially twice that of the line voltage. The circuit is kept near resonance at all times, hence a high power factor is maintained.

At start, on a constant potential line voltage of 220 A. C., a similar lighting tube to the one just explained would draw 0.9 of an ampere or 185 watts at a volt-ampere reading of 198, thus working at a power factor of 93%. A Five minutes later, the watt meter would read 240- and the volt-amperes 242 giving a power factor of 95%. Ten minutes later the reading would be 265 watts and 275 va. or 96% P. F.;' fifteen minutes later 300 w. and 304 va. or 98% P. F.; twenty minutes shown by the arrows. Another composite coil 13 later 320 w. and 330 va. or 97% P. F. In twentyfive minutes, the tube would be at full luminosity and the line reading 400 w. and 418 va., and have a P. F. of 95%. These figures are given from an actual test and show that applicant has prerality of lighting devices at a high power factor;-

a magnetic core having long legs joined together by short legs at the ends thereof, a magnetic bridge of large cross section wedged between the long legs at the longitudinal centers thereof, a plurality of induction coils arranged in series and fixed to the core on the long legs, said coils being positioned on both sides of the bridge and ar-- ranged to cause the fiux generated in the coils of each leg to flow in opposition and then pass across the bridge in a common direction, a supply of electrical current for energizing said coils and devices, a condenser connected between one lead of the electrical supply and a point between the coils on one leg of the core.

2. An electrical system for starting and main taining gaseous electric discharge lamps at a high power factor including a magnetic core having two coil legs joined at their ends by means to form an iron circuit, a pair of spaced apart coils wound in opposite directions on each coil leg, a. magnetic bridge across the spaces between said coils, said coils having a series connection and a wire terminal at each end of the series and also at the mid-point of the series, an electric discharge lamp having a terminal at each end, one terminal of the lamp having connection with one end of the series of coils and the other end terminal of the lamp having connection with wire means leading to a source of electrical power, the other end terminal of the coils having connection with said power source, and a choke coil and condenser connected in series and having one end thereof connected to said wire means and the other end thereof connected to the mid-point of the coils.

WILLARD C. HALL, JR.