US 2043023 A
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Description (OCR text may contain errors)
u 1936- w. F. WESTENDORP 2,043,023
cmcun-s ANDEAPPARATUS FOR OPERATING ELECTRIC DISCHARGE LAMPS Filed Feb. 23, 1955 Fig; 1
High Pressur- Mercury ya arLnm lnventorz Willem F. Westenolor His ttorneg.
Patented June 2, 1936 UNITED STATES PATENT OFFICE CIRCUITS AND APPARATUS FOR OPERAT- ING ELECTRIC DISCHARGE LAMIPS Willem F. Westcndorp, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York My invention relates to electric-discharge lamps, and more particularly to a circuit and I apparatus for operating them.
One object of my invention is toprovide an improved circuit and apparatus for regulating the voltage and current in a series operated discharge lamp throughout the starting and operating period.
Another object of my invention is to provide means for converting into light the available energy not used by the discharge lamp during its operating period.
For a better understanding of my invention, together with other and further objectsthereof, 1 reference is had to the following description,
taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.
In the accompanying drawing, Fig. 1 is a sche- 20 matic diagram illustrating my invention, and
Figs. 2 and 3 are modifications thereof.
Referring to Fig. 1 in detail, a transformer Ill.
8 The electric-discharge lamp I4 is of the type In this type of lamp a metal vapor, such as mercury, for example, is used, which during operation of the lamp rises to a pressure substantially equal to atmospheric pressure, and the lamp is, therefore, usually referred to as high pressure mercury vapor lamp. Among the characteristics of this type of lamp are a. high current and comparatively low voltage at starting approximately 5 45 amperes at 20 volts, a high voltage and low current during operation, approximately 2.9 amperes at 155 volts. During cold weather it is necessary to heat the lamp to 0 C. or above before it will take even a starting current. Since it is desira- 50 ble to operate these lamps on standard series street lighting circuits in which a constant current is maintained, special apparatus must be provided to control the voltage and to make use of the energy which is available for each lamp. 55 Referring to Fig.- 1 again, it will be apparent described in United States Patent 1,948,261, assigned to the assignee of the present invention.
that incandescent lamp l5 being connected in multiple with the lamp l4 will be energized at the instant that the current flows in circuit l2. As
stated above, the current flowing through' the di'schargelamp Id at the beginning of the operation is comparatively high (5 amps.) so that a comparatively low voltage (20 v.) is obtained due to the reactance of the transformer. The incandescent lamp l5 takes a negligible amount of current at this voltage. During warm weather a discharge lamp will start very quickly and the operating current will immediately diminish thereby raising the voltage across the two lamps. When normal operating voltage (in the present instance 155 v.) is reached the incandescent lamp carries its full load current and the discharge lamp acts as a voltage regulator. The transformer i0 is designed to furnish the necessary current at the normal operating voltage for both lamps. In cold weather, however, the discharge lamp M will allow no current to pass so that the voltage across the two lamps will rise and'energize coil l6 which, as stated above, is in multiple with the two mentioned lamps. This coil is arranged to move its armature when a predetermined voltage is reached; in the present instance at approximately 200 volts. Its contacts are thereby closed and the circuit to the third lamp is established. This circuit may be traced from winding I3, through conductor 2|, lamp 20, conductor 22, contacts I 8 and I9, contact bar I! and through conductor 23 to the winding l3. As long as the discharge lamp l4 does not allow current to pass, the coil l6 will maintain the circuit to lamp 20 closed. The two lamps l5 and 20 will, therefore, convert the-available energy into light and can be mounted close enough to the discharge lamp to raise the temperature thereof by radiation. When the temperature of this lamp is raised, the discharge willstart and the voltage across this lamp will fall to a low value, e. g. 20 volts, thereby reducing the current in coil l6 which drops the contact bar I! and disconnects the incandescent lamp 20. As this discharge lamp I 4 then reaches normal operating conditionsthe voltage again rises and the incandescent lamp l5, which remains in the circuit, again reaches full brilliance and the dis- V discharge lamp I4 is connected across a secondary winding 30 having a low voltage tap 3| across which the incandescent lamps l5 and 20 are connected. The relay coil 26 in this figure operates two contact bars 32 and 33. When the lamp I5 is energized, the coil 26 is also energized and establishes a circuit to lamp M by means of its contact bar '32 and to coil l6 by means of its contact bar 33.
The circuit to the incandescent filament lamp l5 may be traced from winding 30 to conductor 34, relay coil 26, lamp l5, conductor 2| to tap 3| on the winding 30. The circuit to the discharge lamp ll may be traced from the winding 30 through the conductor 35, the lamp II, the conductor 38, the relay contacts 31 and 38, the bar 32, the conductor 34, to the opposite terminal of the winding 30. By this means each lamp l5 and I4 may be operated at its most eificient voltage and the actual division of power between the" lamps remains the same as in the previous circuits as illustrated in Figs. 1 and 2.
What I claim as new and desire to secure by Letters Patent of the United States, is:
1. In combination, a transformer having a substantially constant current primary circuit, an electric discharge lamp having a variable energy demand during starting and operating periods and an incandescent filament lamp, said lamps being connected to said transformer in multiple whereby the substantially constant cur-=' rent available from said transformer is proportioned between said lamps. Y
2. In combination, a transformer having a substantially constant current primary circuit, an electric discharge lamp having a high current starting characteristic and a low current operating characteristic and an incandescent filament lamp, said lamps being connected to said transformer in multiple whereby the available power is proportioned between said lamps during the starting and operationg periods of said discharge lamp.
3. In a lighting unit, the combination of a transformer having a substantially constant current in its primary winding, an incandescent filament lamp and an electric discharge lamp connected in multiple across the secondary of said transformer, a second incandescent filament lamp and means for automatically connecting said incandescent lamp in multiple when said discharge lamp fails to start.
4. In combination, a transformer having a sub stantially constant current primary circuit, a secondary winding, an electric discharge lamp, an intermediate voltage tap on said secondary winding, an incandescent filament lamp connected thereto, and means responsive to current flowing through said incandescent lamp for connecting said discharge lamp across said secondary winding. V
5. In combination, a transformer having a substantially constant current primary circuit, a secondary winding, an electric discharge lamp, an intermediate voltage tap on said secondary winding having an incandescent lamp connected thereto, means responsive to current flowing in said incandescent lamp for connecting said discharge lamp across said secondary winding, and means responsive to an increase in voltage above the operating voltage of said discharge lamp 35 for connecting a second incandescent filament lamp in multiple with said first incandescent filament lamp.
WIILEM F. WESTENDORP.