Abstract:
THERE IS DISCLOSED A HIGH POWER SQUARE WAVE SUSTAINING GENERATOR SYSTEM FOR A GAS DISCHARGE PANEL PARTICULARLY OF THE TYPE IN WHICH DISCHARGE SITES IN A THIN GASEOUS DISCHARGE MEDIUM CONFINED IN A SPACE BETWEEN A PAIR OF DIELECTRIC CHARGE STORAGE MEMBERS ARE DEFINED BY A PAIR OF MATRIX CONDUCTOR ARRAYS. THYRISTOR PAIRS ARE SERIES CONNECTED ACROSS A HIGH DIRECT CURRENT VOLTAGE POTENTIAL SOURCE WITH AN INTERMEDIATE POINT BETWEEN THE THYRISTOR PAIR BEING CONNECTED TO CONDUCTORS OF ONE OF THE ARRAYS. A SECOND THRYSTOR PAIR IS SERIES CONNECTED ACROSS A SECOND SOURCE OF HIGH VOLTAGE DIRECT CURRENT POTENTIAL OF OPPOSITE POLARITY TO THAT OF THE FIRST SOURCE. A FREE-RUNNING MULTIVIBRATOR OPERATING AT DOUBLE THE DESIRED FREQUENCY OF OUTPUT OF SQUARE WAVES HAS ITS OUTPUT DIVIDED BY A BISTABLE FLIP-FLOP CIRCUIT AND TWO OUTPUT VOLTAGES (EACH THE COMPLEMENT OF THE OTHER) FROM THE FLIP-FLOP ARE FED TO ONE-SHOT MULTIVIBRATORS AND THE OUTPUT OF THE ONE-SHOT MULTIVIBRATORS ARE USED AS CONTROL OR TRIGGER POTENTIALS FOR THE GATE ELECTRODES OF THE THYRISTORS. SUCH CONTROL POTENTIALS ARE APPLIED AS TRIGGER POTENTIALS TO THE GATE ELECTRODE OF ONE THYRISTOR OF A PAIR TO CAUSE IT TO CONDUCT AND A BLOCKING POTENTIAL IS APPLIED TO THE GATE ELECTRODE OF THE OTHER OF THE THYRISTORS TO MAINTAIN IT NONCONDUCTIVE WHEREBY CURRENT FLOWS FROM THE FIRST HIGH VOLTAGE SOURCE TO THE CAPACITIVE LOAD THROUGH THE CONDUCTIVE THYRISTOR AND ON APPLICATION OF A TRIGGER POTENTIAL TO THE SECOND THYRISTOR OF THE PAIR AND A BLOCKING POTENTIAL TO THE FORMERLY CONDUCTING THYRISTOR, THE SECOND THYRISTOR OF THE SERIES PAIR IS CAUSED TO CONDUCT THEREBY DISCHARGING CURRENT FROM THE LOAD. THE OTHER CONDUCTOR ARRAY OF THE PAIR IS SUPPLIED WITH SQUARE WAVE POTENTIALS IN A SIMILAR MANNER BUT OF OPPOSITE POLARITY. TRANSFORMERS HAVING DOUBLE SECONDARIES ARE USED TO SIMULTANEOUSLY SUPPLY TRIGGER POTENTIALS TO THE GATE ELECTRODES OF THE THYRISTORS WHICH ARE DESIRED TO BE CONDUCTIVE TO THEREBY SUPPLY CHARGING CURRENT TO THE PANEL AND A BLOCKING POTENTIAL TO THE GATE ELECTRODE OF THE OTHER THYRISTORS TO RENDER THEM NONCONDUCTIVE. A PROTECTION CIRCUIT IS ALSO PROVIDED IN THE EVENT BOTH THYRISTORS OF A SERIES PAIR ARE RENDERED CONDUCTIVE AT THE SAME TIME. IN ADDITION, THERE IS DISCLOSED A SERIES LOSSY INDUCTOR IN THE CIRCUIT TO THE CONDUCTOR ARRAYS TO LIMIT PEAK CURRENT AND RING CURRENTS TO THE LOAD. CONSULT THE SPECIFICATION FOR OTHER FEATURES AND DETAILS.