Emergency light control and battery charging system
First Claim
1. A system adapted for connection to a source of conventional electrical AC power, a battery, and a light, said system being arranged to keep said battery charged from said AC power source and in the event of a disruption in said AC power source to energize said light from said battery, said system comprising:
- power supply means for converting said conventional electrical AC power to DC power between a supply line and a reference line;
charging means including switched voltage regulating means coupled between said power supply means and said battery for selectively charging said battery to maintain the battery voltage within a predetermined range;
latch means coupled to said power supply means for providing a latch signal upon the initial connection of said system to said AC power source; and
enable means coupled to said power supply means and to receive said latch signal for energizing said light from said battery when said latch signal is present and said DC power is absent, said enable means including a field effect transistor in series with said light and voltage doubling means connected to the gate of said field effect transistor.
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Accused Products
Abstract
An emergency light control and battery charging system utilizes a temperature compensated switched voltage regulator for charging the battery. Energization of the emergency light is effected through a field effect transistor which is turned on through a voltage doubler circuit enabled when there is a failure in the power supply. The system is arranged with a latch that insures that the light is not turned on when the battery is connected until after line power is initially applied. A low battery voltage detector insures that the battery is protected from a deep cycle discharge if line voltage is not restored.
23 Citations
12 Claims
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1. A system adapted for connection to a source of conventional electrical AC power, a battery, and a light, said system being arranged to keep said battery charged from said AC power source and in the event of a disruption in said AC power source to energize said light from said battery, said system comprising:
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power supply means for converting said conventional electrical AC power to DC power between a supply line and a reference line; charging means including switched voltage regulating means coupled between said power supply means and said battery for selectively charging said battery to maintain the battery voltage within a predetermined range; latch means coupled to said power supply means for providing a latch signal upon the initial connection of said system to said AC power source; and enable means coupled to said power supply means and to receive said latch signal for energizing said light from said battery when said latch signal is present and said DC power is absent, said enable means including a field effect transistor in series with said light and voltage doubling means connected to the gate of said field effect transistor. - View Dependent Claims (2, 3, 4, 5)
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6. A system adapted for connection to a source of conventional electrical AC power, a battery, and a light, said system being arranged to keep said battery charged from said AC power source and in the event of a disruption in said AC power source to energize said light from said battery, said system comprising:
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power supply means for converting said conventional electrical AC power to DC power between a supply line and a reference line; charging means including switched voltage regulating means coupled between said power supply means and said battery for selectively charging said battery to maintain the battery voltage within a predetermined range; latch means coupled to said power supply means for providing a latch signal upon the initial connection of said system to said AC power source; and enable means coupled to said power supply means and to receive said latch signal for energizing said light from said battery when said latch signal is present and said DC power is absent; said charging means comprising a silicon controlled rectifier with its anode-to-cathode path in series between said power supply means and said battery, and means for controlling the conduction of said silicon controlled rectifier in a switched manner including; a series string of a resistor, a diode, and a Zener diode connected between said supply line and said reference line; a potentiometer connected across said diode; and means for connecting the gate of said silicon controlled rectifier to the tap of said potentiometer. - View Dependent Claims (7)
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8. A system adapted for connection to a source of conventional electrical AC power, a battery, and a light, said system being arranged to keep said battery charged from said AC power source and in the event of a disruption in said AC power source to energize said light from said battery, said system comprising:
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power supply means for converting said conventional electrical AC power to DC power between a supply line and a reference line including; a transformer having a primary winding and a center tapped secondary winding; means for connecting said primary winding to said AC power source; and diode bridge means connected across said secondary winding to provide said DC power between said reference line and said supply line;
charging means coupled between said power supply means and said battery for selectively charging said battery to maintain the battery voltage within a predetermined range, including;a silicon controlled rectifier having its cathode connected to the center tap of said secondary winding and its anode connected to the positive terminal of said battery; means for connecting the negative terminal of said battery to said reference line; a resistor having a first end connected to said supply line; a potentiometer having a first end connected to the second end of said resistor and its variable tap connected to the gate of said silicon controlled rectifier; a Zener diode having its anode connected to the second end of said potentiometer and its cathode connected to said reference line; and a diode having its cathode connected to the first end of said potentiometer and its anode connected to the second end of said potentiometer, said diode having a negative temperature characteristic so that as the ambient temperature decreases the voltage drop across said diode increases; latch means coupled to said power supply means for providing a latch signal upon the initial connection of said system to said AC power source; and enable means coupled to said power supply means and to receive said latch signal for energizing said light from said battery when said latch signal is present and said DC power is absent. - View Dependent Claims (9, 10, 11, 12)
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Specification