MULTI-CHANNEL PULSE SEQUENCING TO CONTROL THE CHARGING AND DISCHARGING OF CAPACITORS INTO AN INDUCTIVE LOAD

Abstract

Apparatus and method for multi-channel pulse sequencing to control the charging and discharging of two capacitors into an inductive load. The invention allows devices that produce alternating magnetic fields (induction heating, AC motors, metal detectors, MRIs, wireless communication) to operate above 100% efficiency; thereby producing a power gain. The results of this improvement will allow these devices to be portable and low cost.

Claims

1. A method of providing multi-channel pulse sequencing power control, comprising: applying a direct current power source to a pulse width modulation (PWM) module to activate each of a first charging switch and a second charging switch; charging a first capacitor coupled to the first charging switch and a second capacitor coupled to the second charging switch; activating a first bidirectional switch by the PWM module to allow the first capacitor and an inductive load to oscillate for a first temporal period; and activating a second bidirectional switch by the PWM module after the first temporal period to allow the second capacitor and the inductive load to oscillate for a second temporal period.

2. The method of claim 1, further comprising: activating the first bidirectional switch after the second temporal period.

3. The method of claim 1, further comprising: alternately activating the first bidirectional switch and the second bidirectional switch after the first temporal period and the second temporal period.

4. The method of claim 1, further comprising: deactivating the first bidirectional switch after expiration of the first temporal period; and deactivating the second bidirectional switch after an expiration of the second temporal period.

5. The method of claim 4, further comprising: activating the first charging switch during oscillation of the second capacitor and the inductive load to fully charge the first capacitor.

6. The method of claim 5, wherein the first charging switch is activated after half of the second temporal period.

7. The method of claim 4, further comprising: activating the second charging switch during oscillation of the first capacitor and the inductive load to fully charge the second capacitor.

8. The method of claim 7, wherein the second charging switch is activated after half of the first temporal period.

9. The method of claim 1, further comprising: removing the direct current power source to the PWM module; activating both the first bidirectional switch and the second bidirectional switch; and deactivating each of the first charging switch and the second charging switch to discharge each of the first capacitor and the second capacitor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic view of a multi-channel pulse sequencing control circuit;

[0013] FIG. 2 is a flow chart of the invention; and

[0014] FIG. 3 is a schematic view of an alternate embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

[0016] Broadly, embodiments of the present invention provide an improved apparatus and method for multi-channel pulse sequencing to control the charging and discharging of capacitors into an inductive load.

[0017] The present invention breaks through that limitation by creating a circuity process that allows stored energy from a couple of recently charged capacitors and a single inductor to oscillate current back and forth for a small portion of time. This momentary oscillation with the single inductor as a load will provide AC output magnetic fields with no momentary input signal. This will provide an average power gain.

[0018] By allowing one of two capacitors to sequentially charge while the other capacitor is discharging into the inductive load, such as a coil, a pulsed input power is provided while producing a continuous output power. Current devices require continuous input power to achieve a continuous output power.

[0019] The multi-channel pulse sequencing control allows alternating magnetic field producing electronic systems, such as induction heaters, AC motors, wireless coupling, and MRI systems, to operate with efficiencies above 100%. This is accomplished by momentary stored energy in the device or system to generate momentary alternating fields without any input energy.

[0020] As seen in reference to the drawings of FIG. 1, a power source 10 provides a DC power to input terminals of the device. The DC power supply 10 could be a battery, an AC to DC converter, AC to DC adaptor, as the type of DC power supply 10 can vary with the particular application. In other embodiments a power supply voltage indicator, or sensor circuit, could alert the user that the input voltage is low. A fuse may also be provided to protect the battery and the multi-channel pulse sequencing control of the present invention from a short circuit condition.

[0021] The DC power supply 10 charges capacitors C1 18 and C2 20 simultaneously through a pulse width modulation (PWM) module 12. The PWM module 12 activates a pair of charging switches on Sw1 14 and Sw2 16. Capacitors C1 18 and C2 20 are fully and partially charged, respectively.

[0022] The PWM module 12 is also configured to send a pulse to a first bidirectional switch Sw3 22 to allow the first capacitor C1 18 and an inductor 26 to oscillate for a predetermined period of time. In a two capacitor configuration, halfway into the oscillation between C1 18 and the inductor 26, the PWM module 12 activates the second charging switch Sw2 16 to allow the power source 10 to fully charge C2 20. After the second capacitor C2 20 is fully charged, the oscillation between the first capacitor C1 18 and the inductor 26 stops and the second capacitor C2 20 and the inductor 26 begin to oscillate through the PWM module 12 activation of a second bidirectional Sw4 24. Halfway into the oscillation between the second capacitor C2 20 and the inductor 26, the PWM module 12 activates the first charging switch Sw1 14 to allow the power source 10 to charge the first capacitor C1 18. In other embodiments, a plurality of capacitors and a corresponding charging switch may be sequentially activated by the PWM module 12.

[0023] Each charging switch and bidirectional may be implemented with number of digitally controlled switches, such as IGBT, BJT, MOSFETS, thyristors, and the like. Depending on the type switch, the respective input connections may variously be designated as a collector, a base, or an emitter. For ease of description, the switches described herein will have a first connector, a second connector, and a control connector, with the control connector indicating the terminal for activation or deactivation of the switch.

[0024] The multi-channel pulse sequencing control circuit function described above will continue to repeat until the circuit is turned off by the user or removal of the power supply 10 from the input terminals. During the times of oscillation between C1 18 and C2 20 and the inductor 26, the power source 10 is not providing any current.

[0025] The foregoing components may be assembled onto a flat platform and use electrical wiring or print circuit board traces to interconnect the components. The platform may then be installed inside an enclosure and a power supply and inductive coil 26, or load would be connected as described above.

[0026] Likewise, a potentiometer could be used to adjust the output power.

[0027] In the non-limiting embodiment shown in reference to FIG. 1, a first charging switch 14 and a second charging switch 16 each have a collector attached to the positive input terminal and a base connected to one of a plurality of output terminals of a pulse width modulation (PWM) module 12. An emitter of the first charging switch 14 is attached to a first end of the first capacitor 18 and an emitter of the second charging switch 16 is attached to a first end of the second capacitor 20. A base of each of a first bidirectional switch 22 and a second bidirectional switch 24 is attached to a separate one of the plurality of output terminals of the PWM 12 An emitter of each of the first bidirectional switch 22 and the second bidirectional switch 24 are coupled to the positive output terminal. A collector of the first bidirectional switch 22 is coupled to the first end of the first capacitor 18 and a collector of the second bidirectional switch 24 is coupled to the first end of the second capacitor 20.

[0028] In an alternative embodiment, shown in reference to FIG. 3, a full-bridge inverter module 28 can be added to transmit alternating signals into a resistive load 30 instead of the inductive load 26. The full-bridge inverter module 28 connects across the outputs of the multi-channel pulse sequencing control.

[0029] To use this invention, one needs to connect a DC power supply 10 to the inputs of the multi-channel pulse sequencing control. Likewise, the inductive load 26 is operatively coupled to the output of the multi-channel pulse sequencing control. This present invention can be used induction heating and forging systems, AC motors, wireless communication, MRI, and metal detectors.

[0030] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.