Ac power changeover

Claim 2

An electrical power changeover system comprising, in combination, a first supply of electrical current, a second supply of electrical current constituting an operator controlled engine driven generator, an electrical load, first switch means normally electrically connecting said load to said first supply and operable to connect said load to said second supply and disconnect said load from said first supply, second switch means in series with said first switch means between said first switch means and said second supply selectively controlling energization of said first switch means from said second supply, first switch control means controlling said first switch means in dependence upon the output of said second supply, second switch control means controlling said second switch means in accord with operation of said second supply, and means controlling at least one of said switch control means wherein said switch means operate at different times such that said load is not energized from said second supply until the load is disconnected from said first supply and said second supply attains predetermined voltage characteristics, and said load being disconnected from said second supply during de-energizing of said second supply prior to being connected to said first supply by a time interval sufficient to prevent arcing at said first switch means.

Claim 3

An electrical power changeover system comprising, in combination, a first supply of electrical current, a second supply of electrical current constituting an operator controlled engine driven generator, an electrical load, a first switch selectively electrically connecting said load to said first and second supplies and normally connecting said load to said first supply, a second normally open switch electrically interposed between said second supply and said first switch in series with said first switch, first control means operating said first switch upon energization of said second supply to permit connection of said load to said second supply, and second control means closing said second switch after a predetermined time interval after energization of said second supply to connect said load to said second supply and opening upon de-energization of said second supply and prior to operation of said first switch to connect said load to said first supply.

Claim 4

An electrical power changeover system comprising, in combination, a first supply of electrical current, a second supply of electrical current constituting an operator controlled engine driven generator, an electrical load, a first switch selectively electrically connecting said load to said first and second supplies and normally connecting said load to said first supply, a second normally open switch electrically interposed between said second supply and said first switch in series with said first switch, first control means operating said first switch upon energization of said second supply to permit connection of said load to said second supply, and second control means closing said second switch after a predetermined time interval after energization of said second supply to connect said load to said second supply and opening upon de-energization of said second supply and prior to operation of said first switch to connect said load to said first supply.

Claim 5

An eleCtrical power changeover system as in claim 2 wherein said second control means includes time delay means delaying operation of said second switch a predetermined time interval after energization of said engine driven generator.

Claim 6

An electrical power changeover system as in claim 2 wherein said second control means includes an electromagnetic relay and a resistance in series with said relay causing de-energizing of said relay and opening of said second switch at a higher voltage output of said second supply than the voltage required to operate said first control means to open said first switch.

Claim 7

An electrical power changeover circuit comprising, in combination, a first supply of electrical current having an active conductor and a ground conductor, a second supply of electrical current having an active conductor and a ground conductor comprising an operator controlled motor driven generator, a load having active and ground conductors, first relay switch means controlled by said second supply for selectively connecting said load active and ground conductors to said active and ground conductors, respectively, of said first and second supplies of electrical current, said first relay switch means normally connecting said load conductors to corresponding conductors of said first supply, and connecting said load conductors to corresponding conductors of said second supply upon energizing of said motor driven generator and disconnecting said load conductors from said second supply conductors upon the output of said motor driven generator falling below the operating voltage of said first relay switch means, second switch means located in at least one of said conductors of said second supply of electrical current, and means energized from said second supply closing said second switch means upon said motor driven generator second supply attaining a predetermined voltage output upon being energized and opening said second switch means upon said motor driven generator being de-energized and prior to said first switch means disconnecting said load conductors from said second supply conductors.

Claim 8

An electrical power changeover circuit comprising, in combination, a first supply of electrical current having an active conductor and a ground conductor, a second supply of electrical current having an active conductor and a ground conductor comprising an operator controlled motor driven generator, a load having active and ground conductors, first relay switch means controlled by said second supply for selectively connecting said load active and ground conductors to said active and ground conductors, respectively, of said first and second supplies of electrical current, said first relay switch means normally connecting said load conductors to corresponding conductors of said first supply, and connecting said load conductors to corresponding conductors of said second supply upon energizing of said motor driven generator and disconnecting said load conductors from said second supply conductors upon the output of said motor driven generator falling below the operating voltage of said first relay switch means, second switch means located in at least one of said conductors of said second supply of electrical current, and means energized from said second supply closing said second switch means upon said motor driven generator second supply attaining a predetermined voltage output upon being energized and opening said second switch means upon said motor driven generator being de-energized and prior to said first switch means disconnecting said load conductors from said second supply conductors.

Claim 9

In an electrical power changeover circuit as in claim 5 wherein said means opening and closing said second switch means comprises a time delay switch controlling said second switch means.

Claim 10

In an electrical power changeover circuit as in claim 6, a resistor in series with the circuit of said time delay switch causing said second switch means to open prior to operation of said first switch means to connect said load conductors to said first supply conductors.

Claim 11

In an electrical power changeover circuit as in claim 5 wherein said first and second supplies of electrical current provide alternating current, current rectifying means connected to said second supply producing a direct current output, said first relay switch means being connected to said rectifying means output.

Claim 12

In an electrical power changeover circuit as in claim 8 wherein said second switch means comprises a relay, and conductors selectively connecting said second switch relay to said rectifying means output.