US1622505A - Automatic control for arc lamps - Google Patents

Description

March 29 1927. 1,622,505

C. M. FOX

AUTOMATIQCONTROL FOR ARC LAMPS Filed Aug. 6, 1925 anomm i atented Mar. 29, 1927.

UNITED STATESPATE'NT orrlcui CECIL M. FOX, 01? TOLEDO, OHIO.

AUTOMATIC CONTROL FOR ARC LAMPS.

Application filed August 6, 1925. Serial No. 48,575.

viding an electrically operated device for controlling the speed of the carbon in an arc lamp wherein the variation in potential across the arc is utilized for controlling the operation of the automatic feed device so that the carbons of the lamp are maintained at the proper distance apart for producing the most eficient are light.

Another object of the invention resides in providing an arc lampstructure with an automatic feed device wherein a reversible .motor is provided with independent fields for controlling the rotation of the armature adapted to be energized alternately for pro ducing a forward or reverse feed of the carbon to vary the gap automatically in accordance with the variance in potential acrosssaid gap, means being provided for manually controlling the operation of the device for adjusting the operation thereof in order that the proper gap may be maintained between the carbons for producing a most eiiicient are light.

The inyention comprehends other objects and improvements in the details of construction and arrangement of the parts which are more particularly pointed out in the following detailed description and in the claims, directed to apreferred form of the invention, it being understood however, that various changes inthe details of construction may be made for carrying out the principle of the invention without departing from the spirit or scope thereof as herein set forth.

Tn the drawing forming partof this application,

The view is a diagrammatic illustration of the carbon of an arc lamp and the mechanism forming the subject matter of the pres ent invention, shown inits operation relation therewith. I

1 indicates a bracket supporting the positive carbon 2 while the negative carbon 3. is

mounted in the bracket 4, both ofwhich brackets are slidably mounted in order to.

permit an axial movement of the carbon so that the gap may be adjusted in order to maintain the proper are for producing the most efiicient light. "A feed screw 5 pro-.

vidcd with reverse threads on the opposite end portion thereof threadedly engages the brackets 1 and 4 so that in the rotation of 9. The armature of the motor has the usual commutator 15 with which the brushes 16 and 17, engage in the usual manner.

The posltive and negative conductors from a suitable source of power are illustrated at 18 and 19 respectively, the conductor 18 being connected with the carbon supporting bracket 1 for interposing the positive carbon 2 in circuit with the source of energy, while the negative conductor from the source of power extends to the resistance 20 which is of a fixed and predetermined character from which the'wire 21 extends to the bracket 4 of the negative carbon. A wire connection 22 extends from the positive conductor 18 to one terminal of the field 12 while the opposite terminal of the field 12 is connected with the wire 23 to one terminal of the field 13. The top of the terminal or field 13 is connected by the wire 24 to the variable resistance 25 which has the opposite terminal thereof connected to the negative conductor 19. A wire connection 26 is connected to character, the potential varies across thecarbon in accordance with the length of the arc, advantage being taken of' this variation of potential across the carbon for the purpose of controlling the motor in order that the proper feed and arc may be maintained automatically. When the resistance across the positive and negative carbons 2 and 3 respectively is high due to a substantially large gap between the carbon, producing a'snbstantiall long are or no are at all, current will ow from the positive conductor l8 through the wire 22 to the field 12, then through the wire 23 to the wire '26 and through the brushes 17 the armature 11, and to the brush 16 trom which current flows to the negative side of the line through the wire 27 and 21 and through resistance 20. This flow of current will produce an operation of-the armature to rotate the shaft 14: and the worm 9 and thereby rotate the feed screw 5 in order to feed the carbons toward each other for the purpose of striking the are. As the carbons engage and strike the arc the resistance across the carbons will be substantially low as a result of which the current will flow from the positive side of the lamp through the carbons 2 and 3 and through the wire 27 to the brush 16'. From the brush 16 it will fiow through the' commutator 15 and armature 11 to the brush 17 and wire 23. The current will then flow into-the field 13 and through wire 2e and variable resistance 25 to the negative side of the line in view of the fact that the resistance through this circuit is less than the resistance through the wire'21 and resistance 20. This rotation of the armature from that caused by the field12 and the energization of the circuit above mentioned which will produce a movement of the carbons away from each other after the arc is struck in order to lengthen the same which will increase the brilliancy of the arc and the light produced thereby. This operation will take place un- '12at which time the same til the carbons are separated to increase the resistance across the are between the electrodes 2 and 3 to a point where the current which fiows through the field 12 will build up to rent flow in the field 13, which will efiect a balance in the circuit through the fields 12 and 13. as above mentioned and will hold the armature stationary.

After thearc is struck and the armature rotates in a reverse direction, it will gradually slow down as the potential increases across the arc until it is equalized in the arc circuit and the circuit through the field will be held stationary, and upon any variance in the potential due to the burning away of the carbon which will increase the are and increase the potential, the armature will be operated by the field 20 suificient-ly to move the carbonstogether in order to maintain a uniform arc; The distance at which this are is maintained is controlled by the position of the variable resistance 25 whichcontrols the balance in the circuit and thereby controls the position at which the mohas: been provided for will produce a reverse an extent to equalize the cur automatically striking the are between the carbons of an arc lamp and thereafter maintaining such a gap between the carbons as will produce the most efficient light generation. This automatic control is produced as above described in accordance with the variation of potential across the arc and through the two circuits, each including one of the independent fields of the motor which controls the operation of the reversible motor to produce in a most simple manner the proper automatic control of-vthe arc.

Having thus described my invention, what I claim as new is I 1. In an arc lamp, electrodes, a motor to cause adjustment of said electrodes, said motor comprising independent field windin'gs and an armature, and meansto supply current to said motor when the electrodes need adjustment including means to cause current to pass through the armature in one irection and to energize afield winding to have a dominating effect thereon when the are resistance is too high and to cause current to pass through the armature in the other direction and to energize another thereon when the arc-resistance is too low.

2. In an arc lamp, electrodes, a motor to i cause adjustment of said electrodes, said motor comprising windings and an armature, and means to supply current to said motor when the electrodes need adjustment including means to cause current to pass through the armature in one direction and to energize a field winding to have a dominating ctlect thereon when the arc resistance is too high andto cause current to pass through the armature in the other direction and to energize the other field winding to have a dominating eti'ect thereon when the arc resistance is too low.

3. In an arc lamp, electrodes, a motor to cause adjustment of said electrodes, said motor comprising independent field windings and an armature, and means to supply current to said motor when the electrodes need adjustment including means to cause current the armature 1n one dito pass through rection and to energize a field winding to have a dommating effect thereon when the two independent field,

are resistance is too high and to cause cnrrent to pass through the armature in the other direction and to energize another. field winding to'have a dominating eil'ect thereon when the are resistance is too low, the cur-- rent passing through the one field winding passing therethrough in the same direction whether the arc resistance be high or low, and the current passing through the other field winding passing therethrough in the same direction whether the arc resistance be high or low. I

4. In an arc lamp, electrodes, a motor to cause adjustment of said electrodes, said windings being stone bridge,'a source motor comprising two independent fieldwindings and an armature, and means to supply current to said motor when the electrodes need adjustment including means tocause current to pass through the armature in one direction and to energize a field winding to have a dominating efi'ect thereon when the arc resistance is too high and to cause current to pass through the armature in the other direction and to energize the other field winding to have a dominating effect thereon when the arc resistance is too low, the current passing through the one field winding passing therethrough in the same direction whether the arc resistance be high or low, and the current other field winding the same direction be high or low.

5. In an arc lamp, a \Vheatstone bridge, electrodes adapted to form an arc in one leg of said bridge, a motor con'iprising an armature and two field windings, one of said field windings being in another leg of said \Vheatstone bridge,

passing through the passing therethrough in whether the arc resistance stone bridge, the armature being connected across the meeting point of two legs of said WVheatstone bridge and the meeting point of the other two legs of said \Vheatstone bridge, and a source of power connected across the other two meeting points of said bridge legs, wherebythe arc will be maintained at a constant value. a

6. In an arc lamp, a lVheatstone bridge, electrodes adapted to form an arc in one leg of said bridge, a motor comprising an-armature and two field windings, one of said field windings being in another leg I of said \Vheatstone bridge, the other of said field in another leg of said lVheatstone bridge, the armature being connected across the meeting point of two legs of said \Vheatstone bridge and the meeting point of the other two legs of said Vheatof power connected across i he other two meeting points of said bridge legs, whereby the arc will be maintained at a constant value. and an adjustable resistance in a leg with a field winding whereby the constant value of the arc may be predetermined and varied.

7.'In an arc lamp, a VVheatstone bridge, electrodes adapted to form an arc in one leg of said bridge, a motor comprising an armatureand two field windings, one of said field windings being in a leg of said VVheatstone' bridge adjacent to said first mentioned leg.

a connection for one side of a source of power at the meeting point of said legs, the

' connection for one side of a source the other of said field windings being in another leg of said Wheatother field winding being in a leg of said Wheatstone bridge adjacent to said second mentioned leg, a resistance in the fourth leg of said \Vhcatstone bridge, said fourth leg being adjacent said first mentioned and third mentioned legs, a connection at the meeting point of said third and fourth mentioned legs for the other side of the source of power, said armature being connected between the meeting point of said first and fourth mentioned legs and the meeting point of said second and third mentioned legs.

8. In an arc lamp, a Wheatstone bridge, electrodes adapted to form of said bridge, a motor comprising an armature and two field windings, one of said field windings being in a leg of said lVheatstone brioge adjacent to said first mentioned leg, at of power at the meeting point of said legs, the other field winding being in a leg of said \Vhcatstone bridge adjacent to said second mentioned leg, a resistance in the fourth leg of said lVheatstone bridge, said fourth leg being adjacent said first mentioned and third mentioned legs, a connection at the meeting point of said third and fourth mentioned legs for the other side of the source of power, said armature being connected between the meeting point of said first and fourth mentioned legs and the meeting point of said second and third mentioned legs, and an adjustable resistance in a leg with one of said field windings.

9. In an arc lamp, a \Vheatstone bridge, electrodes adapted to form an arc in one leg of said bridge, a motor comprising an armature and two field windings, one of said field windings being in a leg of said Wheatstone bridge adjacent to said first mentioned leg, :1 connection for one side of a source of power at the meeting point of said legs, the other field winding being in a leg of said Wheatstone bridge adjacent to said second mentioned leg, :1 of said lVheatstone bridge, said fourth leg being adjacent said first mentioned and third mentioned legs, a connection at the meeting point of said third and fourth mentioned legs for the other side of the'source of power, said armature being connected between the meeting point of said first and fourth mentioned legs and the meeting point of said second and third mentioned legs, and an adjustable resistance in the third mentioned leg including said second mentioned field winding.

In testimony whereof I afiix my signature.

CECIL M. FOX.

an arc in one leg resistance in the fourth leg

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