Dual battery charging generator system

• US 3,962,621 A
• Filed: 01/16/1975
• Issued: 06/08/1976
• Est. Priority Date: 10/15/1973
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Raver, Louis J.
• Primary Examiner(s): Budd, Mark O.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/541,624
• Time in Patent Office: 509 Days
• Field of Search: 320/15, 320/17, 320/61, 320/46, 320/6, 310/68 D, 307/16, 322/28, 322/90
• US Class Current: 320/123
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02K 11/02 for suppression of electromagnetic interference
• CPC Class Codes: H02K 11/05 Rectifiers associated with casings, enclosures or brackets
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery charging generator which is capable of charging two series connected batteries in a motor vehicle electrical system where the series connected batteries are used to energize the cranking motor of a motor vehicle. The generator is of the alternating current type and has first and second three-phase full-wave bridge rectifier units built into the end frame of the generator each of which is capable of supplying charging current to one of the batteries. The generator has a built-in transistor voltage regulator which senses the voltage applied to the main battery of the system by the first bridge rectifier and which regulates the output voltage of the generator to a predetermined value. The second bridge rectifier supplies charging current to an auxiliary battery and is connected with the stator winding of the alternating current generator by means of a three-phase transformer. The transformer, like the bridge rectifiers, is built into the end frame of the generator and isolates the two bridge rectifiers of the system. The generator is arranged with a 12 volt and a 24 volt output terminal which only need be connected directly to the batteries when installing a generator on a motor vehicle.

Claims

1. An electrical system associated with an internal combustion engine comprising, a load battery having a predetermined voltage rating, a second auxiliary battery of like voltage rating, first, second and third terminals, means connecting said load battery between said first and second terminals, means connecting said auxiliary battery between said second and third terminals, a cranking motor circuit connected across said first and third terminals, an electrical load circuit connected across said first and second terminals, a polyphase alternating current generator having a polyphase output winding and a field winding, a polyphase rectifier having A.C. input terminals and two direct voltage output terminals, means connecting said input terminals of said polyphase rectifier to said output winding, said polyphase rectifier operable to rectify the polyphase output voltage generated in said output winding into a direct voltage appearing across the direct voltage output terminals of said polyphase rectifier, means connecting said two direct voltage output terminals of said polyphase rectifier respectively to said first and second terminals, a voltage regulator connected to sense the voltage across said load battery and across said direct voltage output terminals of said polyphase rectifier for controlling the energization of said field winding to thereby maintain the voltage across said load battery at a desired regulated value, an isolation transformer having primary and secondary windings, means connecting said primary winding of said isolation transformer to said output winding, a second rectifier having input terminals and two output terminals, means connecting said secondary winding of said isolation transformer to said input terminals of said second rectifier, means connecting said two ouutput terminals of said second rectifier to said second and third terminals, the turns ratio of said isolation transformer being such as to produce an open circuit average voltage at the output of said second rectifier substantially equal to 0.97 of the open circuit average voltage at the output of said polyphase rectifier.

2. An electrical system for charging a pair of series-connected batteries that are adapted to energize an electrical cranking motor circuit comprising, a first load battery, a second auxiliary battery of like voltage rating, first, second and third terminal means, means connecting said first load battery between said first and second terminal means, means connecting said auxiliary battery between said second and third terminal means whereby said batteries are connected in series additive relationship between said first and third terminal means, said first and third terminal means being adapted to supply a cranking motor circuit at a voltage equal to the series-additive voltages of said batteries, an alternating current generator having a three phase output winding and a field winding, a first three phase fullwave bridge rectifier having A.C. input terminals and direct voltage output terminals, means connecting said A.C. input terminals of said first bridge rectifier to said three phase output winding of said generator, means connecting said direct voltage output terminals of said first bridge rectifier with said first and second terminal means whereby said first load battery is charged thereby, a three phase transformer having primary and secondary windings, a second three phase full-wave bridge rectifier having A.C. input terminals and direct voltage output terminals, means connecting said primary winding of said transformer to said output winding, means connecting said secondary winding of said transformer to said A.C. input terminals of said second bridge rectifier, means connecting the direct voltage output terminals of said second bridge rectifier across said second and third terminal means whereby said second auxiliary battery is charged thereby, and a voltage regulator connected to said field winding and with the direct voltage output terminals of said first bridge rectifier, said voltage regulator controlling field current to control the magnitude of the voltage generated in said output winding to provide a desired regulated voltage at the output of said first bridge rectifier and across said first load battery in response to the voltage applied to said first load battery from the direct voltage output terminals of said first bridge rectifier, the ratio of secondary turns to primary turns of said transformer being substantially equal to 0.97 to thereby step-down the transformer input voltage.