Three-lamp lead lag rapid start ballast apparatus

Claim 2

Apparatus for igniting and operating three gaseous discharge devices of the rapid start type comprising: A. a transformer having a ferromagnetic core comprising a first part and a second part and means providing for substantial flux leakage between the parts, B. a primary winding and first, second and third secondary windings mounted on said core, the primary winding and first secondary winding being mounted in close coupled relation on the first part and the second and third secondary windings being mounted in close coupled relation on the second part, C. means comprising terminal leads for connecting the primary winding across an a.c. line of voltage insufficient to ignite any one of said devices, D. means for forming with two devices a lead side of said apparatus and for forming with one device a lag side of said apparatus and comprising i. for said lead side a first condenser, a second condenser and conductors for connecting two devices, said first condenser, the third secondary and the primary winding in series with the windings in additive autotransformer relation and said second condenser shunting one device, and ii. for said lag side, a choke and conductors for connecting the third device, said choke, the first and second secondary and the primary windings in series with the windings in additive autotransformer relation, E. The turns ratios and phase relations being such that on open circuit the lead side devices will have a voltage applied thereto sufficient to ignite said devices in sequence and will tend to ignite first and said lag side device will have a certain voltage applied thereto, after ignition of said lead side devices said certain voltage will be increased to assist in igniting said lag side device if it has not already been ignited, and the devices thereafter remaining ignited at substantially normal operating conditions.

Claim 3

The apparatus as claimed in claim 1 in which the voltage applied to said lead side devices on open circuit will be the minimum practical starting voltage for two devices while the said certain voltage applied to said lag side device on open circuit is less than the minimum practical starting voltage for a single device but after ignition of the said lead side devices the voltage applied to said lag side device will be increased to at least minimum practical starting voltage.

Claim 4

The apparatus as claimed in claim 1 in which the voltages applied to said devices on open circuit are the minimum required starting voltages.

Claim 5

The apparatus as claimed in claim 1 in which the primary winding, third secondary winding and one of said first and second secondary windings have a terminal end in common connected to one of said terminal leads.

Claim 6

The apparatus as claimed in claim 1 in which one of said first and second secondary windings and said primary winding have a first terminal end in common and in which said third secondary winding and primary winding have a second terminal end in common, the first and second terminal ends being opposite terminals of said primary winding and connected respectively to said terminal leads.

Claim 7

The apparatus as claimed in claim 5 in which said second terminal is adapted to be grounded and said means for forming the lag side include connections to a disconnect socket for said lag side device.

Claim 8

Apparatus for igniting and operating three gaseous discharge devices of the rapid start type comprising: A. a transformer having a ferromagnetic core comprising a first part and a second part and means providing for substantial flux leakage between the parts, B. a primary winding and two secondary windings mounted on said core, one secondary winding being a lead secondary winding and the other being a lag secondary winding, the primary winding being mounted on the first part of the core, the lead secondary winding being mounted on the second part of said core, and the lag secondary winding having one portion thereof closely coupled to the lead secondary winding, C. means comprising terminal leads for connecting the primary winding across an a.c. line of voltage insufficient to ignite any one of the devices, D. means including electrical leads and two condensers for forming with two devices and said transformer a lead loop, with the devices, one condenser, the primary winding and the lead secondary winding all connected in series, the second condenser shunting one device and the primary and secondary windings being additive, in said lead loop, E. means including electrical leads and a choke for forming with a third device and said transformer a lag loop, with the third device, the choke, the primary winding and the lag secondary winding all connected in series, the primary and secondary windings being additive in said lag loop, F. the primary winding being common to both loops and cooperating with said lead secondary winding to evolve a voltage on open circuit in the lead loop sufficient to ignite the unshunted device following which the shunted device will ignite and thereafter operating lead current will flow in series through said lead loop, the primary winding also cooperating with the lag secondary winding to evolve a voltage in the lag secondary winding on open circuit which is raised when said lead current flows in said lead secondary such that the combined primary and lag secondary voltages in said lag loop will be sufficient to ignite said third device, and G. the choke serving to provide inductive reactance in said lag loop for providing lagging operating current therein.

Claim 9

Apparatus for igniting and operating three gaseous discharge devices of the rapid start type comprising: A. a transformer having a ferromagnetic core comprising a first part and a second part and means providing for substantial flux leakage between the parts, B. a primary winding and two secondary windings mounted on said core, one secondary winding being a lead secondary winding and the other being a lag secondary winding, the primary winding being mounted on the first part of the core, the lead secondary winding being mounted on the second part of said core, and the lag secondary winding having one portion thereof closely coupled to the lead secondary winding, C. means comprising terminal leads for connecting the primary winding across an a.c. line of voltage insufficient to ignite any one of the devices, D. means including electrical leads and two condensers for forming with two devices and said transformer a lead loop, with the devices, one condenser, the primary winding and the lead secondary winding all connected in series, the second condenser shunting one device and the primary and secondary windings being additive, in said lead loop, E. means including electrical leads and a choke for forming with a third device and said transformer a lag loop, with the third device, the choke, the primary winding and the lag secondary winding all connected in series, the primary and secondary windings being additive in said lag loop, F. the primary winding being common to both loops and cooperating with said lead secondary winding to evolve a voltage on open circuit in the lead loop sufficient to ignite the unshunted device following which the shunted device will ignite and thereafter operating lead current will flow in series through said lead loop, the primary winding also cooperating with the lag secondary winding to evolve a voltage in the lag secondary winding on open circuit which is raised when said lead current flows in said lead secondary such that the combined primary and lag secondary voltages in said lag loop will be sufficient to ignite said third device, and G. the choke serving to provide inductive reactance in said lag loop for providing lagging operating current therein.

Claim 10

The apparatus as claimed in claim 7 in which the open circuit voltage available across both devices of said lead loop is the minimum practical voltage for igniting two devices in series, and the open circuit voltage available across the third device of the lag loop is less than the minimum practical voltage for igniting a single device but is raised to minimum practical starting voltage after both devices of the lead loop are operating.

Claim 11

The apparatus as claimed in claim 7 in which the voltages applied to said devices on open circuit are the minimum practical starting voltages such that although the devices of the lead loop tend to ignite first, the third device will have sufficient open circuit voltage to ignite independently but will ignite more readily should the lead devices ignite first.

Claim 12

The apparatus as claimed in claim 7 in which the open circuit voltages available to all of said devices comprises the minimum required voltages for ignition.

Claim 13

A gaseous discharge device system comprising: A. a high leakage reactance transformer having two ferromagnetic parts separated by shunting means, a primary winding and a step-up lead secondary winding mounted on the respective parts loosely coupled relative to one another, a step-up lag secondary winding having two portions each mounted on the respective parts in loose coupled relation to one another but in close coupled relation to the respective primary and lead secondary windings, B. a pair of series connected gaseous discharge devices of the rapid start type and a condenser shunting one device, C. a second condenser, D. a third gaseous discharge device of the rapid start type, E. a choke, F. means for connecting the primary winding to a source of a.c. power the voltage of which is insufficient to ignite any device, G. a lead loop formed by the series connected devices, the second condenser, the lead secondary winding and the primary winding, with the windings connected additive in said lead loop, H. a lag loop formed by the third device, the choke, the lag secondary winding and the primary winding, with the windings connected additive in the said lag loop, I. the turns relationships and phase relationships being such that upon ignition of the deviceS, a leading current will flow in the lead loop and a lagging current will flow in the lag loop.

Claim 14

A gaseous discharge device system comprising: A. a high leakage reactance transformer having two ferromagnetic parts separated by shunting means, a primary winding and a step-up lead secondary winding mounted on the respective parts loosely coupled relative to one another, a step-up lag secondary winding having two portions each mounted on the respective parts in loose coupled relation to one another but in close coupled relation to the respective primary and lead secondary windings, B. a pair of series connected gaseous discharge devices of the rapid start type and a condenser shunting one device, C. a second condenser, D. a third gaseous discharge device of the rapid start type, E. a choke, F. means for connecting the primary winding to a source of a.c. power the voltage of which is insufficient to ignite any device, G. a lead loop formed by the series connected devices, the second condenser, the lead secondary winding and the primary winding, with the windings connected additive in said lead loop, H. a lag loop formed by the third device, the choke, the lag secondary winding and the primary winding, with the windings connected additive in the said lag loop, I. the turns relationships and phase relationships being such that upon ignition of the deviceS, a leading current will flow in the lead loop and a lagging current will flow in the lag loop.

Claim 15

The apparatus as claimed in claim 11 in which the pair of devices of the lead loop will on open circuit have a voltage applied thereto which is sufficient to ignite the devices in sequence and said pair of devices will tend to ignite before the third device, the lag secondary winding and primary winding upon open circuit applying a voltage across said third device which is raised after ignition of said pair of devices to assist in ignition thereof, if it hasn''t already ignited.

Claim 16

The apparatus as claimed in claim 11 in which the secondary and primary windings have a terminal in common.

Claim 17

The apparatus as claimed in claim 11 in which the lag secondary winding has a terminal common to one terminal of the primary winding and the lead secondary winding has a terminal common with the second terminal of the primary winding.

Claim 18

The apparatus as claimed in claim 14 in which said means for connecting said primary winding to a source include an electrical lead connected to said second terminal, the third device has a disconnect socket including spaced contacts in said electrical lead bridged only when said device is in said socket but otherwise open to deenergize said primary winding.

Claim 19

The apparatus as claimed in claim 15 in which said electrical lead is grounded.

Claim 20

The apparatus as claimed in claim 11 in which said devices have filaments in the ends thereof and said transformer includes a plurality of filament windings closely coupled with said primary winding and connected to energize said filaments.