HIGH EFFICIENCY POWER SUPPLY FOR CHARGING CAPACITORS IN STEPS

• US 3,654,537 A
• Filed: 04/29/1970
• Issued: 04/04/1972
• Est. Priority Date: 04/29/1970
• Status: Expired due to Term

• Current Assignee: David W. Coffey
• Original Assignee: David W. Coffey
• Inventors: Coffey, David W.
• Primary Examiner(s): Konick, Bernard
• Assistant Examiner(s): Hecker, Stuart
• Application Number:
  US05/032,923
• Time in Patent Office: 706 Days
• Field of Search: 307/109,110,246,52,61,71,77,83 320/1
• US Class Current: 320/166
• CPC Class Codes: A61N 1/025 Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: B23K 11/26 Storage discharge welding
• CPC Class Codes: H01S 3/092 of flash lamp H01S3/0937 takes precedence ; flash lamps per se H01J61/80; circuit arrangements for operating flash lamps in general H05B41/30
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/337 in push-pull configuration H02M3/33576 takes precedence; with self-oscillating arrangements H02M3/3382, H02M3/3385
• CPC Class Codes: H02M 7/10 arranged for operation in series, e.g. for multiplication of voltage
• CPC Class Codes: H03K 3/57 the switching device being a semiconductor device
• CPC Class Codes: H05B 41/2821 by means of a single-switch converter or a parallel push-pull converter in the final stage H05B41/285 takes precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A system for direct current resonant charging of capacitors in which the size and weight of the power supply and an inductive choke for limiting surge currents can be materially reduced by charging the capacitor in successive steps, each of a higher voltage level than the preceding step. This reduces the current surge from the supply during each step and also reduces the size of the required choke.

Claims

1. In a system for charging a capacitor by direct current resonant charging techniques, the combination of a pair of input terminals adapted for connection to a source of direct current power, a transfer device having a direct current chopper circuit connected to said terminals and inductively coupled through primary winding means to a plurality of secondary windings, each secondary winding having a different turns ratio with respect to said primary winding means whereby the voltages appearing across said secondary windings will differ one from the other, full wave rectifier means connected to the output of said secondary windings, transistor switch means for connecting said secondary windings across said capacitor in sequence whereby the voltage across the capacitor will rise in steps, an inductive choke interposed between said input terminals and said capacitor, and a synchronizing circuit connected to the bases of said transistors for causing them to fire in sequence.

2. The system of claim 1 wherein said transistors are fired in sequence to connect the secondary windings to said capacitor such that the voltage across said capacitor increases in steps.

3. The system of claim 1 including rectifiers interposed between said secondary windings and said transistors.

4. The system of claim 3 including diodes connected across the output terminals of said rectifiers.

5. The system of claim 4 wherein the output voltages across said rectifiers are applied in series across said capacitor.