Ripple detecting polarity indicator for battery charger

• US 4,654,575 A
• Filed: 02/18/1986
• Issued: 03/31/1987
• Est. Priority Date: 02/18/1986
• Status: Expired due to Term

• Current Assignee: Clore Automotive, LLC (C3 Holdings LLC)
• Original Assignee: Century Manufacturing Incorporated
• Inventors: Castleman, Cordell V.
• Primary Examiner(s): HICKEY, ROBERT
• Application Number:
  US06/830,126
• Time in Patent Office: 406 Days
• Field of Search: 320/2-5, 320/20, 320/25, 320/48, 302/10 R, 302/10 BP, 340/636
• US Class Current: 340/636.13
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045
• CPC Class Codes: Y10S 320/20 Polarity

Abstract

A ripple current component detecting circuitry embodied in the terminal of a cable connecting a battery charger with a lead acid storage battery to improve safety of use by preventing the indication of a correct polarity of connection where a charger is energized before connection is made with the battery when in fact such an indication may be incorrect, the prevention of such an indication being accomplished by the utilization of the AC ripple component in the charger output. The circuitry detects the ripple and with its use overrides what would otherwise be given as a misleading indication of polarity.

Claims

1. In connection with a battery charger output cable connected with an energized charger,the terminal of said cable embodying circuitry responsive to an AC ripple component in the battery charger output, said circuitry comprising

during an interval of increasing voltage of the ripple component in a battery charger output,

a first capacitor responsive to an AC ripple component passing current to the base-emitter junction of a transmitter,

a second capacitor discharging current from said base-emitter junction,

a correct polarity indicator,

said second capacitor diverting current which would otherwise pass through and energize said correct polarity indicator,

an incorrect polarity indicator in circuit with said second capacitor being reversely biased relative to said current passing from said second capacitor,

during an interval of decreasing voltage of said ripple component in said battery charger output,

said first capacitor reversing the direction of said current discharging the same through a second circuit including said second capacitor, said second capacitor having such a greater magnitude of capacitance value than said first capacitor as to pass insufficient voltage to energize said correct polarity indicator and said incorrect polarity indicator being biased relative to said reverse direction of current is energized thereby.

2. In connection with a battery charger output cable connected with an energized charger, a terminal of said cable embodying an AC ripple detecting circuitry, comprising

a battery charger having an output of DC voltage including an AC ripple component and having in circuit therewith,

during an interval of increasing voltage of the AC ripple component of said charger output,

a first capacitor responsive to detecting said ripple component passes current,

a transistor in circuit with said capacitor,

a correct polarity indicatior,

a second capacitor having greater capacitance value than said first capacitor and in circuit therewith with said transistor and with said indicator,

said transistor passing current discharging said second capacitor and said second capacitor diverting current from passing through said indicator,

an incorrect polarity indicator in circuit with said first capacitor and being reversely biased relative to said current passing through first capacitor,

during an interval of decreasing voltage of said ripple component of said charger output,

said first capacitor reversing the direction of flow of said current through a second circuit including said second capoacitor,

said second capacitor, accepting said current from said first capacitor and passing said current to said incorrect polarity indicator in circuit therewith and having the same polarity as said reversed current, and

the voltage across said second capacitor not attaining a magnitude sufficient to energize said correct polarity indicator.

3. In connection with a battery charger output cable connected only with an energized charger, a terminal of said cable embodying an AC ripple detecting circuitry, said circuitry comprising

a battery charger having a current output of DC voltage including an AC ripple component,

a non-polarized capacitor receiving and passing said current responsive to said AC ripple component,

an incorrect polarity indicator,

a base-emitter junction of a NPN transistor,

a base-emitter junction of a PNP transistor,

a second incorrect polarity indicator,

said ripple compnent flowing alternately through said first mentioned base-emitter junction and through said second mentioned base-emitter junction,

whereby said indicators are energized alternately indicating an incorrect cable connection to an energized charger before connection to a battery.

4. The circuitry of claim 3, including

capacitors respectively in circuit with the collectors of said first and second mentioned transistors,

said ripple component alternately energizing said transistors, said transistors discharging said capacitors accordingly,

first and second correct polarity indicators respectively in circuit with said capacitors,

means passing a unidirectional current through said indicators,

said transistors when turned on shunting said unidirectional current from said indicators, and

said capacitors respectively attaining insufficient voltage when their respective transistors are off, to energize their respective indicators.

5. In connection with a battery charger output cable connected only with an energized charger, a terminal of said cable embodying an AC ripple component detecting cicuitry, said circuitry comprising

a battery charger having an output including an AC ripple component and a unidirectional component,

a first capacitor blocking the unidirectional component of said output,

said capacitor passing said AC ripple component of said output,

a second non-polarized capacitor,

a first and a second diode,

said second diode biased to pass said ripple component to charge said second capacitor during intervals when the voltage of the AC ripple component of said charger output is increasing,

said first diode providing a return path for said ripple component during the intervals when said charger output is decreasing,

current latching means triggered by said second capacitor upon said second capacitor becoming sufficiently charged by several cycles of AC ripple component,

a first and second oppositely biased correct polarity indicators,

said current latching means shunting out said indicators not permitting the same to become energized,

whereby the operator is alerted to an incorrect cable connection.

6. In connection with a battery charger output cable connected only with an energized charger, a terminal of said cable embodying an AC ripple component detecting circuitry, said circuit comprising

a battery charger having an output including an AC ripple component and a unidirectional current component,

a first capacitor blocking said unidirectional current component of said battery charger output and passing said AC ripple component therein,

a second capacitor charged by said ripple component,

an opto electronic isolator means in circuit with a photo-transistor inside a four diode bridge having bi-directional input infra red LEDs in circuit with and between said first and second capacitors, and

a first and second oppositely biased correct polarity indicators shunted out by said second capacitor,

whereby the operator is alerted of an incorrect cable connection by prevention of the lighting of a correct polarity indicator.

7. The circuitry of claim 6, including

diodes respectively in circuit with said polarity indicators causing such an increase in voltage to energize the same that said indicators do not light.