| 摘要 |
A system for sealing a mount in a cathode-ray tube using first and second tiers of burners includes a first valve in an oxygen supply line and a third valve in a fuel supply line connected to the first tier, and a second valve in the oxygen supply line and a fourth valve in the fuel supply line connected to the second tier for controlling, respectively, the flow of oxygen and fuel therethrough. The system comprises a preignition timing relay responsive to a start signal and coupled to both the first and the third valves for effecting a preignition gas flow period. An ignition timer is responsive to the preignition timing relay and is coupled to both the first and the third valves and to an igniter for effecting an ignition latchup interval at the end of the preignition gas flow period. A first timing relay is responsive to the ignition timer and is coupled to both the first and the third valves for effecting a first-tier gas flow period following the preignition gas flow period. A first overlap timer is responsive to the first timing relay and is coupled to the first valve for continuing the flow of oxygen to the first tier for a first preselected time interval. Also, a second timing relay is responsive to the first timing relay and is coupled to both the second and the fourth valves for effecting a second-tier gas flow period at the end of the first-tier gas flow period.
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