Battery charger

• US 4,207,515 A
• Filed: 05/08/1978
• Issued: 06/10/1980
• Est. Priority Date: 05/16/1977
• Status: Expired due to Term

• Current Assignee: Kokusan Denki Company Limited (MAHLE-STIFTUNG GmbH)
• Original Assignee: Kokusan Denki Company Limited (MAHLE-STIFTUNG GmbH)
• Inventors: Yukawa, Hideki
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US05/905,780
• Time in Patent Office: 764 Days
• Field of Search: 322/28, 322/89-94, 320/40, 320/57, 320/59, 320/61, 320/71
• US Class Current: 320/123
• CPC Class Codes: H02J 7/1492 by means of controlling devices between the generator output and the battery
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A battery charger including a hybrid bridge rectifier circuit adapted to rectify the output of an AC generator to charge a battery is characterized in that the rectifier circuit includes thyristors having the anodes connected to each other to form the negative output terminal of the rectifier circuit and diodes having the cathodes connected to each other to form the positive output terminal of the rectifier circuit. The anodes of the diodes are respectively connected to the cathodes of the thyristors, and the connecting junctions form the input terminals of the rectifier circuit. There is also provided a control circuit adapted to couple the gates of the thyristors to the positive input terminal of the rectifier circuit.

Claims

1. A battery charger including a hybrid bridge rectifier circuit to rectify the output of an AC generator to charge a battery,

wherein said rectifier circuit comprises:

a plurality of thyristors having the anodes connected to each other to form the negative output terminal of the rectifier circuit,

a plurality of diodes having the cathodes connected to each other to form the positive output terminal of the rectifier circuit and having the anodes respectively connected to the cathodes of the thyristors, the junctions between the anodes of the diodes and the cathodes of the thyristors respectively forming the input terminals of the rectifier circuit, and

a plurality of auxiliary diodes having the cathodes respectively connected to the gates of said thyristors and having the anodes connected to each other to form a control terminal of the rectifier circuit, and

further comprising a control circuit including,

a voltage detecting circuit which detects the battery terminal voltage and produces an output signal when the battery terminal voltage exceeds a reference value,

a first transistor having a base connected to the output terminal of said voltage detecting circuit and a collector coupled to said rectifier circuit so as to be conductive when said battery terminal voltage exceeds the reference value,

a second transistor having an emitter connected to the negative terminal of said rectifier circuit and a base coupled to said first transistor so that base current of the second transistor is supplied from said rectifier circuit when said first transistor is nonconductive,

a third transistor having a base coupled to the collector of said second transistor, an emitter coupled to the positive output terminal of said rectifier circuit and a collector coupled to said control terminal of said rectifier,

said second transistor and third transistor being conductive when said first transistor is nonconductive,

resistor means connected across the base and emitter of said third transistor, and

capacitor means connected across the base and collector of said second transistor, said capacitor means being charged when said first transistor is nonconductive and said second transistor is conductive,

the discharging current through said resistor means being in such a direction as to render the base of said third transistor positive relative to the emitter of said third transistor, thereby preventing conduction of said third transistor while said discharging current is flowing.