Power control circuits

Claim 1

IN COMBINATION, A BILATERAL CONTROLLABLE SEMICONDUCTOR SWITCHING DEVICE FOR CONTROLLING THE CURRENT APPLIED TO A LOAD FROM A SOURCE OF ALTERNATING POTENTIAL UNDER CONTROL OF SWITCHING SIGNALS COMPRISING A BODY OF SEMICONDUCTOR MATERIAL INCLUDING FIVE LAYERS OF ONE AND THE OPPOSITE CONDUCTIVITY TYPES, LAYERS OF ONE CONDUCTIVITY TYPE BEING INTERLEAVED WITH LAYERS OF THE OPPOSITE CONDUCTIVITY TYPE FOMRING A PLUARLITY OF P-N JUNCTIONS THEREIN, A FIRST MAIN CURRENT CARRYING ELECTRODE IN LOW RESISTANCE OHMIC CONTACT WITH A SURFACE OF AN EXTERNAL LAYER OF SAID BODY AND AN EXPOSED SURFACE OF AN ADJACENT INTERMEDIATE LAYER, A SECOND MAIN CURRENT CARRYING ELECTRODE IN LOW RESISTANCE OHMIC CONTACT WITH A SURFACE OF THE OTHER EXTERNAL LAYER OF SAID BODY AND AN EXPOSED SURFACE OF AN ADJACENT INTERMEDIATE LAYER, MEANS FOR COUPLING SAID DEVICE IN SERIES BETWEEN SAID FIRST AND SAID SECOND MAIN CURRENT CARRYING ELECTRODES WITH SAID LOAD AND SAID ALTERNATING POTENTIAL, A GATE REGION OF THE SAME CONDUCTIVITY TYPE AS SAID EXTERNAL LAYERS OF SAID BODY ADJACENT SAID INTERMEDIATE LAYER CONTACTED BY SAID FIRST MAIN CURRENT CARRYING ELECTRODE, GATING ELECTRODE MEANS IN OHMIC CONTACT WITH SAID GATE REGION AND WITH THE ADJACENT INTERMEDIATE LAYER, MEANS FOR SWITCHING SAID SEMICONDUCTOR DEVICE BETWEEN HIGH AND LOW IMPEDANCE STATES FOR CURRENT THROUGH SAID DEVICE IN OPPOSITE SENSES COMPRISING MEANS FOR COUPLING SUCH SWITCHING SIGNALS BETWEEN SAID GATE ELECTRODE MEANS AND ONE OF SAID FIRST AND SECOND MAIN CURRENT CARRYING ELECTRODES.