| 摘要 |
To prolong the life of a deuterium gas discharge lamp and reduce photometric noise, a DC potential is applied between the cathode and the anode of the lamp to support the arc current through the tube and a separate AC potential is connected across the cathode through an AC amplitude control circuit that controls the amplitude of the AC current. While the cathode is at room temperature, a potential proportional to the AC current through the cathode is balanced against a potential proportional to the AC potential drop across the cathode in an operational amplifier circuit and the output used to operate an indicating device. During operation of the lamp, the output of the operational amplifier circuit is used to control power applied to the cathode through the AC amplitude control circuit. At this time, the proportionality factor for the AC potential drop is divided by a factor to cause an increase in the AC current through the cathode and rebalance the operational amplifier circuit under lamp operating conditions at point where the cathode energy is just above an anomaly in the cathode-power cathode-temperature curve.
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