Apparatus for providing uninterrupted power to a load

Claim 2

Apparatus for providing standby power comprising, a battery, a load, a source of rectified and filtered AC connected to said load, switching means interposed between said battery and said load, sensing means connected to said battery and said source of rectified and filtered AC for detecting a variation in the voltage of the latter from a given level, means responsive to said sensing means connected to said switching means and said battery for connecting said battery to said load when the voltage from said source of rectified and filtered AC falls below said given level, and means including at least a portion of said switching means and a current limiting resistor serially disposed between said battery and said source of rectified and filtered AC for charging said battery while said load is connected to said source of rectified and filtered AC.

Claim 3

Apparatus for providing standby power comprising, a two-terminal load, a rectified AC source connected to said load, a battery equal in voltage to said given voltage one side of which is directly connected to one terminal of said two-terminal load, means including a saturable element normally nonconducting when said given voltage is supplied from said rectified AC source and conductive when said given voltage falls below said given value connected to the other side of said battery and to the other terminal of said two terminal load for isolating said source when said load is supplied from said rectified AC source, sensing means connected to said battery, said rectified AC source and said isolating means for detecting a variation in said rectified AC source, and means responsive to said sensing means connected to said isolating means to electrically connect said battery across said two terminal load when said given voltage falls below said given value.

Claim 4

Apparatus for providing standby power comprising, a two-terminal load, a rectified AC source connected to said load, a battery equal in voltage to said given voltage one side of which is directly connected to one terminal of said two-terminal load, means including a saturable element normally nonconducting when said given voltage is supplied from said rectified AC source and conductive when said given voltage falls below said given value connected to the other side of said battery and to the other terminal of said two terminal load for isolating said source when said load is supplied from said rectified AC source, sensing means connected to said battery, said rectified AC source and said isolating means for detecting a variation in said rectified AC source, and means responsive to said sensing means connected to said isolating means to electrically connect said battery across said two terminal load when said given voltage falls below said given value.

Claim 5

Apparatus according to claim 1 wherein said switching means is a bipolar transistor.

Claim 6

Apparatus according to claim 1 wherein said sensing means is a bipolar transistor normally nonconductive when the base and emitter thereof are at substantially the same potential from said source of rectified and filtered AC and said battery and conductive when the emitter potential is different from the base potential.

Claim 7

Apparatus according to claim 1 wherein said means responsive to said switching means includes a controlled rectifier element which is normally nonconducting and rendered conductive by the flow of current through said sensing means.

Claim 8

Apparatus according to claim 1 wherein said at least a portion of said switching means is a forward biased PN-junction.

Claim 9

Apparatus according to claim 2 wherein said sensing means is a bipolar transistor normally nonconductive when said rectified AC source and said battery are at the same potential and conductive when said rectified AC source and said battery are at different potentials.

Claim 10

Apparatus according to claim 2 wherein said means responsive to said sensing means is a controlled rectifier element normally nonconducting when said sensing means is nonconducting and conductive when said sensing means is conductive.

Claim 11

Apparatus according to claim 2 further including means connected between said source of rectified AC and said battery to provide a trickle charge thereto when the potential of said source of rectified AC is greater than the potential of said battery.

Claim 12

Apparatus according to claim 2 further including means connected to said battery and to said sensing means for removing said bAttery from said load when said rectified AC source is reapplied to said load at said given voltage.

Claim 13

Apparatus according to claim 2 wherein said saturable element is a bipolar transistor.

Claim 14

Apparatus according to claim 7 wherein said rectified AC source and said battery at different potentials includes said rectified AC source being at a lower potential than said battery.

Claim 15

Apparatus according to claim 9 wherein said means for providing a trickle charge includes at least a portion of said isolating means in series with a current limiting resistor.

Claim 16

Apparatus according to claim 13 wherein said at least a portion of said isolating means is a forward biased PN-junction.

Claim 17

Apparatus according to claim 10 wherein said means for removing said battery from said load includes a normally closed switch serially connected with said battery and said means responsive to said sensing means and another normally closed switch in series with said sensing means both of which are ganged to operate simultaneously.

Claim 18

Apparatus for providing standby power comprising, a two-terminal load, a source of rectified and filtered AC connected to said load, a battery, the negative terminal of which is connected to one terminal of said two-terminal load, a saturable PNP-switching transistor, the collector of which is connected to the other of the terminals of said two-terminal load and the emitter of which is connected to the positive side of said battery, a PNP-sensing transistor, the base of which is connected to the collector of said switching transistor, the emitter of which is connected to the emitter of said switching transistor, a silicon controlled rectifier, one terminal of which is connected to the base of said switching transistor, a second terminal of which is connected via a current-limiting resistor to the negative side of said battery, the control electrode of said controlled rectifier being connected via a current-limiting resistor to the collector of said sensing transistor, said sensing transistor being operative when said rectified AC source falls below the voltage of said battery to turn on said silicon controlled rectifier and provide a current path via said switching transistor to connect said battery to said load.

Claim 19

Apparatus for providing standby power comprising, a two-terminal load, a source of rectified and filtered AC connected to said load, a battery, the negative terminal of which is connected to one terminal of said two-terminal load, a saturable PNP-switching transistor, the collector of which is connected to the other of the terminals of said two-terminal load and the emitter of which is connected to the positive side of said battery, a PNP-sensing transistor, the base of which is connected to the collector of said switching transistor, the emitter of which is connected to the emitter of said switching transistor, a silicon controlled rectifier, one terminal of which is connected to the base of said switching transistor, a second terminal of which is connected via a current-limiting resistor to the negative side of said battery, the control electrode of said controlled rectifier being connected via a current-limiting resistor to the collector of said sensing transistor, said sensing transistor being operative when said rectified AC source falls below the voltage of said battery to turn on said silicon controlled rectifier and provide a current path via said switching transistor to connect said battery to said load.