Thyristor operated photosensitive control for lamp bank display

Claim 2

In an apparatus for controlling the illumination of a plurality of independent lamp units arranged geometrically in a lamp bank and supplied with primary lamp power from a source of electrical energy wherein the electrical current cyclically reaches zero: individual lamp power thyristor means each having a pulse receiving connection and anode-cathode terminals, the anodecathode terminals being respectively connected in a series circuit with the individual lamp units to selectively complete a power circuit therethrough from said source of electrical energy across the respective individual lamp units following reception of a firing pulse at the pulse receiving connection of the lamp power thyristor connected thereto and to continue to conduct current across the anode-cathode terminals during reception of holding current thereby; a firing current source; first control thyristor means; variable conductive means in a series circuit with the pulse receiving connection of each of said lamp power thyristor means and the anode-cathode terminals of said first control thyristor means across the firing current source, said variable conductive means being selectively conditioned to block the reception of firing current at the individual pulse receiving connections or to permit application of firing current at said pulse receiving connections; a holding current source producing a constant current output; and second thyristor means operatively connected in series with the anode-cathode terminals of said lamp power thyristor means across said holding current source.

Claim 4

An apparatus as defined in claim 1 wherein said variable conductive means comprises: individual photocells each having a variable resistance element in series with the pulse receiving connection of the lamp power thyristor means controlled thereby; and controllable light means directed to said photocells to vary the electrical resistance of preselected resistance elements thereof.

Claim 5

An apparatus as defined in claim 3 further comprising: sequentially operable control means connected to said control light means and to said first and second control thyristor means to: a. control the application of light from said controllable light means to the photocells; and b. actuate said first and second control thyristor means by application of a firing pulse to the pulse receiving connections thereof.

Claim 6

An apparatus as defined in claim 3 further comprising: sequentially operable control means connected to said control light means and to said first and second control thyristor means to: a. control the application of light from said controllable light means to the photocells; b. actuate said first and second control thyristor means by application of a firing pulse to the pulse receiving connections thereof; and c. and to maintain the actuation of said second control thyristor means following deactivation of said controllable light source and said first control thyristor means.

Claim 7

In an apparatus for controlling the illumination of a plurality of independent lamp units arranged geometrically in a lamp bank: light responsive conduction means, including a plurality of light receptive members each corresponding to one of the lamp units and arranged in a pattern geometrically corresponding to the arrangement of the respective lamp units in the lamp bank; read lamp means directed toward the light receptive members of said light responsive conduCtion means; read lamp power supply means; read lamp control means interposed in series with said read lamp means in a circuit across said read lamp power supply means to selectively complete a power circuit to said read lamp means; light controlling means physically interposed between said light responsive conduction means and said read lamp means to selectively pass a light pattern therethrough into preselected light receptive members in a pattern geometrically corresponding to the desired lighting pattern of the lamp units in the lamp bank; lamp unit power supply means to provide a pulsating lighting current for said lamp units; gate controlled rectifier means having independent cathode-anode circuits interposed in series with each lamp unit across said lamp unit power supply means; gate power supply means producing an intermittent gate signal having a peak voltage and current adequate to fire said gate controlled rectifier means; each light receptive element being interposed in a series circuit between the gate power supply means and each gate connection of said gate controlled rectifier means connected with the lamp unit corresponding thereto; a memory circuit power supply operable, when activated, to produce a filtered holding current at the output thereof; and memory circuit control means to selectively actuate said memory circuit power supply, the output of said memory circuit power supply being applied to a cathode-anode connection common to said gate controlled rectifier means.

Claim 8

In an apparatus for controlling the illumination of a plurality of independent lamp units arranged geometrically in a lamp bank: light responsive conduction means, including a plurality of light receptive members each corresponding to one of the lamp units and arranged in a pattern geometrically corresponding to the arrangement of the respective lamp units in the lamp bank; read lamp means directed toward the light receptive members of said light responsive conduCtion means; read lamp power supply means; read lamp control means interposed in series with said read lamp means in a circuit across said read lamp power supply means to selectively complete a power circuit to said read lamp means; light controlling means physically interposed between said light responsive conduction means and said read lamp means to selectively pass a light pattern therethrough into preselected light receptive members in a pattern geometrically corresponding to the desired lighting pattern of the lamp units in the lamp bank; lamp unit power supply means to provide a pulsating lighting current for said lamp units; gate controlled rectifier means having independent cathode-anode circuits interposed in series with each lamp unit across said lamp unit power supply means; gate power supply means producing an intermittent gate signal having a peak voltage and current adequate to fire said gate controlled rectifier means; each light receptive element being interposed in a series circuit between the gate power supply means and each gate connection of said gate controlled rectifier means connected with the lamp unit corresponding thereto; a memory circuit power supply operable, when activated, to produce a filtered holding current at the output thereof; and memory circuit control means to selectively actuate said memory circuit power supply, the output of said memory circuit power supply being applied to a cathode-anode connection common to said gate controlled rectifier means.

Claim 9

An apparatus as defined in claim 6 wherein said light controlling means comprises: an axial drum having longitudinal message cards mounted thereon; each of said message cards being provided with preselected apertures to pass light to selected light receptive members of said light responsive conduction means; and said light receptive members being longitudinally aligned adjacent to said drum in a position facing one of said message cards.

Claim 10

An apparatus as defined in claim 7 wherein said read lamp means is mounted in a stationary position inside said drum and light therefrom is directed toward the light receptive members through one of said cards.

Claim 11

An apparatus as defined in claim 7 further comprising: an intermittently operable motor mechanically connected to said drum to selectively shift said drum to bring a preselected card mounted thereon into a position interposed between said read lamp means and said light receptive members.

Claim 12

An apparatus as defined in claim 6 wherein said light controlling means comprises: a plurality of cards each being apertured to provide a preselected light pattern therethrough from said read lamp means to said light receptive members; and indexing means operatively connected to said light controlling means to position a selected one of said cards between said read lamp means and said light receptive members.