DIRECT CURRENT POWER CONVERTER

• US 3,921,197 A
• Filed: 11/27/1973
• Issued: 11/18/1975
• Est. Priority Date: 11/27/1973
• Status: Expired due to Term

• Current Assignee: C & D Charter Power Systems, Inc.
• Original Assignee: Sandor J. Horvath
• Inventors: Horvath, Sandor J.
• Primary Examiner(s): Envall, Jr., R. N.
• Application Number:
  US05/419,327
• Time in Patent Office: 721 Days
• Field of Search: 320/39,40 321/18,45 331/110
• US Class Current: 363/17
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 3/3387 in a push-pull configuration
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A power regulation system for use in electric drive vehicles having a direct current power supply of a relatively high voltage and which requires a source of relatively low direct current for auxiliary purposes, such as for charging a 12 volt auxiliary battery which operates an electrical system in the vehicle other than the drive train. The system includes a converter having a full wave transistor bridge oscillator operable to apply high frequency input to the primary of a step-down power transformer. The rectified output of the secondary of the power transformer is connected across the low voltage battery. Charging current control is achieved by a Schmitt trigger voltage sensor connected across the low voltage battery to deactivate or activate the converter at the upper or lower ends of a predetermined low voltage range.

Claims

1. A voltage converter for operating from a DC power supply having a regulated DC output voltage of a value different from the supply voltage, comprising, in combination, a power transformer having primary and secondary windings, oscillator means for connecting said primary winding to said power supply, said oscillator means including a full wave transistor bridge connecting said primary winding alternately in opposite polarity to said power supply for inducing an alternating current at a different voltage in said secondary winding and a saturable reactor having a primary winding connected in parallel with said power transformer primary winding and having a plurality of secondary windings connected to control conduction of current control transistors in said transistor bridge, means for rectifying said induced secondary current and applying the rectified voltage across a pair of load terminals, and regulator means for monitoring the voltage across said load terminals for deactivating said oscillator means when such voltage exceeds a predetermined maximum value and for activating said oscillator means when such voltage drops below a predetermined minimum value, said regulator means including voltage responsive electronic switch means having an input connected across said load terminals and an output operably connected to a means effective to disable said oscillator means, such that variations in such load terminal voltage above or below said predetermined maximum or minimum values will cause said switch means to change from one state to another to deactivate and activate said oscillator means.

2. A voltage converter, as set forth in claim 1, wherein said regulator means includes a Schmitt trigger, means connecting said Schmitt trigger to said load terminals for sensing the voltage across said load terminals, said Schmitt trigger having an output which changes from one state to another when the load terminal voltage exceeds said predetermined maximum, means for preventing said Schmitt trigger from return to said one state until the load terminal voltage drops below said predetermined minimum, and means for disabling said oscillator means when said Schmitt trigger is in said other state.

3. A voltage converter, as set forth in claim 2, wherein said means connecting said Schmitt trigger to said load terminals includes means for changing the predetermined maximum load terminal voltage at which said Schmitt trigger changes from said one state to said other state.