Method of and apparatus for eliminating priming and carrier sweep-out losses in SCR switching circuits and the like
AssigneeMegapulse, Inc.
InventorPaul R. Johannessen
Life of this patent
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Abstract
This disclosure is directed to SCR charging or other energy-switching circuits provided with priming and carrier sweep-out networks and the like that normally incur energy losses in the priming and sweep-out processes, wherein such losses are obviated by transferring energy resulting from such processes back to the power supplies.
Claims11
A method of eliminating priming and carrier sweep-out losses in SCR switching circuits associated with power supplies and in which energy is stored in response to SCR switching in such circuits, said method comprising delaying the rise of SCR current upon such switching for a predetermined priming interval, thereby also generating additional minority carriers in the SCR;
- limiting the current during the priming interval;
- generating a reverse voltage to effect sweep-out of such minority carriers during a sweep-out interval, limiting the current during the sweep-out interval;
- and transferring the energy resulting in each of said priming and sweep-out intervals back to said power supplies to eliminate heat dissipation of the said resulting energy.
A lossless SCR switching-circuit priming and sweep-out apparatus having, in combination with power supply means adapted to store energy that varies in response to SCR switching, saturable inductance means interposed between the power supply means and SCR means, part of the saturable inductance means being adjusted to provide limited priming current during a predetermined priming interval following switching of the SCR means, and part of said saturable inductance means being adjusted to provide a limited sweep-out current;
- and means connected with said saturable inductance means for transferring back to said power supply means energy resulting from the providing of said priming and sweep-out currents to eliminate heat dissipation of said currents in said circuit.
An SCR switching-circuit apparatus having, in combination with a pair of series connected power supplies provided with a pair of capacitors connected in series across the power supplies for storing energy that varies in response to switching of SCR means, a regenerative load connected to receive the stored energy and wherein the voltage of the energy may exceed the maximum voltage rating of the SCR means, and means for clamping the voltage of said energy to prevent it from exceeding said rating, comprising transformer means the primary winding of which connects to the point of series connection of the capacitors and to the load, the diode means series-connected across said capacitors with the point of series connection of the diode means being connected to a secondary winding of the transformer means.
Dependencies are inferred from the claim text.