Back to results
US 4,410,930 AGranted
Photo voltaic lighting for outdoor telephone booth
AssigneeGladwin Corporation
InventorJerry Yachabach
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeGladwin Corporation
InventorJerry Yachabach
Estimating the term…
A free standing outdoor telephone booth is provided with a photo voltaic (PV) array, one or more rechargeable storage batteries and electrical control circuit which includes a temperature compensated control for limiting the supply of electrical energy from the PV array to the rechargeable battery to avoid over charging the battery, an ambient light (solar insolation) sensing circuit for controlling the electrical lamp load, to turn the lamp ON during dark ambient and OFF during light ambient conditions. In addition, the total discharge limit of the storage battery is controlled to a safe operating limit and a means is disclosed to power a fluorescent lamp at energy conserving intensities with energy derived from the rechargeable storage battery. The lamp control circuitry is preferably constituted by a high frequency power inverter with regulated output power to energize a low wattage fluorescent lamp and to dim the fluorescent lamp when the telephone is not in use. The PV array may be mounted in the roof of the booth, or may be mounted remotely or on adjacent structure on poles disguised as phone signs. Multiple commercially available PV arrays and storage batteries may be connected electrically in parallel to provide higher reliability and/or greater electrical energy capacity.
A illumination system comprising in combination, a fluorescent lamp illumination means, a photo voltaic direct current voltage generator generating means, an direct current storage battery means, means for controllably connecting said photo voltaic direct current voltage generator to said storage battery means, means for detecting ambient light conditions and control circuit means, including means for converting the DC voltage of said storage battery to AC voltage for operating said fluorescent lamp connected to said means for detecting ambient light for causing said illumination means to be energized from said electrical energy storage means when the ambient light falls below a predetermined level, the improvement wherein said means for detecting ambient light intensity includes means for sensing the voltage levels generated by the photo voltaic energy generating means.
In a lighting system for public telephone facility having at least one electrical illumination means, a source of electrical energy for exciting said illumination means from said source of electrical energy, a control circuit including dark-on means for sensing ambient light level and energizing said illumination means when ambient light falls below a predetermined level, the improvement comprising,
In a lighting system a for public telephone facility having at least one fluorescent lamp illumination means, a photo voltaic means for generating electrical energy, storage battery means coupled to said PV means, a control circuit including dark-on means for sensing ambient light level and inverter means for energizing said fluorescent lamp illumination means from said storage battery means only when ambient light falls below a predetermined level, the improvement comprising,
In a system for supplying a fluorescent lamp with AC from a DC battery in which an inverter, including pulse width controlled modulator driving a pair of transistors coupled to the primary windings of an output transformer, provides discharge pulses of AC energy at a high frequency to said lamp, the improvement comprising means for sensing current to said lamp and varying the pulse width of said discharge pulses to maintain the light intensity of said lamp constant when the DC battery voltage varies.
An illumination system comprising in combination, a fluorescent lamp illumination means, a photo voltaic direct current electrical energy generating means, a direct current storage battery for storing electrical energy generated by said photo voltaic generating means, means for connecting said photo voltaic electrical generating means to said direct current storage battery means, means for detecting ambient light conditions and control circuit means connected to said means for detecting ambient light for causing the fluorescent lamp illumination means to be energized from said direct current storage battery means when the ambient light falls below a predetermined level, the improvement comprising means for converting the direct current voltage of said direct current storage battery of alternating current voltage, including a pulse width modulator for generating a controlled pulse width waveform for controlling the lamp intensity and maintaining the lamp intensity constant as said storage battery discharges and its output voltage drops.
A fluorescent illumination system comprising a photo voltaic direct current voltage generating system, a direct current storage battery, means for connecting said photo voltaic direct current voltage generating means to said fluorescent lamp including a first inverter means including an oscillator connected to said storage battery for producing a low voltage heating current for electrodes of said fluorescent lamp at a first high frequency and a pulse width controlled modulator for producing a discharge pulse current at a second high frequency for causing light producing discharges in said fluorescent lamp.
Dependencies are inferred from the claim text.