High efficiency circuit for rapidly charging batteries

• US 4,211,969 A
• Filed: 11/08/1978
• Issued: 07/08/1980
• Est. Priority Date: 11/08/1978
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Steigerwald, Robert L.
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US05/958,698
• Time in Patent Office: 608 Days
• Field of Search: 320/14, 320/20, 320/21, 320/30
• US Class Current: 320/129
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y10S 320/17 Sensing of "gassing" voltage
• CPC Class Codes: Y10S 320/24 Inductor

Abstract

An improved battery charger circuit for rapidly charging batteries by increasing the rate of battery charge acceptance through periodic battery discharge pulses during the charging process includes first and second chopper circuits coupled in parallel through an inductor across the DC source for coupling to a battery.

The first chopper circuit controls the amplitude of battery charge current while the second chopper circuit controls the amplitude of battery discharge current and provides a low impedance conduction path for discharge current to be returned to the DC source, thus realizing an efficient battery charger circuit.

Claims

1. An improved battery charger circuit for rapidly and efficiently charging a battery by providing periodic, substantially lossless battery discharge at a high rate for short intervals during the charging process, comprising:

(a) a DC current source;

(b) energy storage means coupled to said DC current source for alternately storing battery discharge energy during battery discharge intervals and for supplying battery charging current from stored battery discharge energy during selected charging time intervals;

(c) inductive means adapted for coupling to a battery to be charged for maintaining decreasing current conduction therethrough when connection to said DC source and energy storage means is interrupted;

(d) a first chopper circuit coupling said inductive means to said current DC source and said energy storage means, said first chopper circuit responsive to external gate signals for conducting battery charge current therethrough from said DC current source and said energy storage means when said first chopper circuit is gated by an external gate signal for circulating said battery charge current during intervals other than when said first chopper circuit is gated by an external gate signal; and

(e) a second chopper circuit coupling said DC current source and said energy storage means to said inductive means, said second chopper circuit responsive to external gate signals for alternately providing a low loss battery discharge path for high current battery discharge pulses when said second chopper circuit is gated by an external gate signal and for diverting current from said battery discharge path to said energy storage means during intervals other than when said second chopper circuit is gated.

2. The invention according to claim 1 wherein said energy storage means comprises a capacitor.

3. The invention according to claim 1 wherein each of said first and second chopper circuits comprises:

(a) controlled unidirectional conduction means for permitting current conduction therethrough responsive to an external gate signal impressed thereon; and

(b) unidirectional conduction means coupled in series opposition with said controlled unidirectional conduction means.

4. The invention according to claim 3 wherein said energy storage means comprises a capacitor.

5. The invention according to claim 3 wherein said controlled unidirectional conduction means comprises:

(a) a thyristor having a gate control terminal coupled to receive external gate control signals and permitting current conduction therethrough in response to said external gate controlled signals; and

(b) commutating circuit means coupled to said thyristor for extinguishing current conduction therethrough at predetermined intervals.

6. The invention according to claim 5 wherein said energy storage means comprises a capacitor.

7. The invention according to claim 3 wherein said unidirectional conduction means comprises a diode.

8. Apparatus for rapidly and efficiently charging a battery by providing periodic substantially lossless battery discharge at a high rate for short intervals during the charging process, comprising:

(a) a DC current source;

(b) a battery to be charged;

(c) energy storage means coupled to said DC current source for storing battery discharge energy during battery discharge intervals and for supplying battery charge current from stored battery discharge energy during selected charging time intervals;

(d) inductive means coupled to said battery for maintaining decreasing current conduction therethrough when connection to said DC current source and said energy storage means is interrupted;

(e) a first chopper circuit coupling said inductive means to said DC current source and said energy storage means, said first chopper circuit responsive to external gate control signals for conducting battery charge current therethrough from said DC current source and said energy storage means when said first chopper circuit is gated by an external gate signal and for circulating battery charge current during intervals other than when said first chopper circuit is gated; and

(f) a second chopper circuit coupling said inductive means to said DC current source and said energy storage means, said second chopper circuit responsive to external gate control signals for providing a low loss battery discharge path for high current battery discharge pulses when said second chopper circuit is gated by an external gate signal and for diverting battery discharge current into said energy storage means during intervals other than when said second chopper circuit is gated.