Energy storage method and apparatus

• US 3,868,562 A
• Filed: 08/02/1973
• Issued: 02/25/1975
• Est. Priority Date: 08/02/1973
• Status: Expired due to Term

• Current Assignee: Eg&G, Inc. (C.T. Consultants Inc.)
• Original Assignee: Duane Marshall
• Inventors: Marshall, Duane
• Primary Examiner(s): Pellinen, A. D.
• Application Number:
  US05/384,964
• Time in Patent Office: 572 Days
• Field of Search: 317/33R,33SC 320/22,39,40 321/11,12,13,16,18 323/22T,23,25 307/93
• US Class Current: 363/53
• CPC Class Codes: G05F 1/573 with overcurrent detector

Abstract

A novel energy storage element charging technique wherein a transistor or similar series pass element in the charging circuit is automatically by-passed by a high-current SCR non-linear circuit during high charging currents, and serves thereafter to regulate the stored voltage. The technique is also useful for over-current protection in conventional regulated power supplies.

Claims

2. A method as claimed in claim 1 and in which said regulating comprises feeding back a sample of the stored energy to control the conduction and thus impedance of the series pass linear path.

3. A method of reducing power dissipation under wide load variations in capacitor energy storage systems through a relatively low-current series pass linear path from an a.c. voltage source, that comprises, initially passing pulsating rectified a.c. current from said source through the linear path to start the capacitor charging and the resulting energy storage;

automatically responding to the initial relatively high current from said source through said linear path to by-pass said series pass linear path by a non-linear high current path each half-cycle of the a.c. voltage repetitively until substantially full charging and energy storage is attained; and

thereupon and thereafter confining the current from said source to said series pass linear path while regulating the same to maintain the desired energy storage.

4. An energy storage apparatus having, in combination, an a.c. voltage source provided with means for producing pulsating rectified voltage therefrom;

storage means;

a linear circuit connecting said source to said storage means through series pass means;

regulating feed-back circuit means connected from said storage means to said pass means to control the impedance thereof;

relatively high-current switching means connected, when effective, to form a non-linear high-current energy storage path;

means responsive to the initial high current in the linear circuit from said source through said series pass means upon initiation of energy storage for rendering said switching means effective to by-pass said series pass means each half cycle of tHe said a.c. voltage repetitively until the energy storage is substantially completed and for thereupon maintaining said switching means ineffective such that the current from said source is thereupon and thereafter passed from said source through the regulated series pass linear circuit, thereby to maintain the energy storage at the desired level.

5. Apparatus as claimed in claim 4 and in which said energy storage means comprises capacitor means.

6. Apparatus as claimed in claim 4 and in which said energy storage means comprises battery means.

7. A capacitor charging and storage apparatus having, in combination, an a.c. voltage source provided with means for producing pulsating rectified voltage therefrom;

storage capacitor means;

a relatively low-current linear circuit connecting said source to said capacitor means through series pass means;

regulating feed-back circuit means connected from said capacitor means to said pass means to control the impedance thereof;

relatively high-current switching means connected, when effective, to form a non-linear high-current charging path;

means responsive to the initial high-current in the low-current linear circuit from said source through said series pass means upon initiation of charging for rendering said switching means effective to by-pass said series pass means each half cycle of the said a.c. voltage repetitively until said capacitor means is substantially charged and for thereupon maintaining said switching means ineffective such that the current from said source is thereupon and thereafter passed from said source through the regulated series pass linear circuit, thereby to maintain the capacitor storage at the desired level.

8. Apparatus as claimed in claim 7 and in which said series pass means comprises transistor means and said switching means comprises SCR means connected to respond to high current in said linear circuit.

9. Apparatus as claimed in claim 8 and in which means is provided to discharge said capacitor means and thereupon repeat said charging.

10. Apparatus as claimed in claim 9 and in which said transistor means has collector, emitter and base electrodes and is connected with said collector and emitter in series with resistance in said linear circuit and said base connected with said regulating feed-back circuit means;

and said SCR means has anode, cathode and gate electrodes and is connected with said anode and cathode in parallel with said collector, emitter and resistance, and with said gate connected to a point of said linear circuit to respond to the voltage developed across said resistance.

11. Apparatus as claimed in claim 10 and in which diode means is connected between said resistance and said base.

12. Apparatus as claimed in claim 10 and in which diode means is connected between said SCR and said capacitor means.

13. Apparatus as claimed in claim 10 and in which said source connected in the charging circuit comprises a parallel inductance-capacitance network the inductance of which is adjusted to establish the initial maximum charging current and the capacitance of which is adjusted to reduce the charge time, the said capacitance being further adjusted to resonate with said inductance means at a frequency higher than that of the said a.c. voltage.