摘要:
A radiation source (10) with an ionizable mercury-free composition (12). The ionizable composition comprising at least zinc or at least one zinc compound or both.
摘要:
A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to “switch on” a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and “switch off” the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.
摘要:
A cold-cathode switching device is presented. The cold-cathode switching device (100) includes a housing (110) defining a chamber (111); an ionizable gas (112) disposed in the chamber; and a plurality of electrodes (120) disposed in the chamber. The plurality of electrodes includes a cathode (124) and an anode (122) defining a discharge gap, and wherein at least one of the cathode and anode comprises a material (140) that is liquid at an operating temperature of the cathode or the anode.
摘要:
A barium-free electron emissive material comprises a barium-free metal oxide composition and operable to emit electrons hermal on excitation. The metal oxide is selected from the group consisting of calcium oxide, strontium oxide, magnesium oxide and combinations thereof. A lamp including an envelope, an electrode including a barium-free election emissive material and a discharge material, is also disclosed.
摘要:
A high-voltage direct-current (HVDC) transmission system includes an alternating current (AC) electrical source and a power converter channel that includes an AC-DC converter electrically coupled to the electrical source and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and the DC-AC inverter each include a plurality of legs that includes at least one switching device. The power converter channel further includes a commutating circuit communicatively coupled to one or more switching devices. The commutating circuit is configured to “switch on” one of the switching devices during a first portion of a cycle of the H-bridge switching circuits and “switch off” the switching device during a second portion of the cycle of the first and second H-bridge switching circuits.
摘要:
A light source (71, 80, 90) includes a base (72), a light-transmissive envelope (73, 93) 'coupled to the base (72), a composition (10) disposed within the light-transmissive envelope (73, 93), and a gas phase contained by the envelope (73, 93) for suppressing vaporization of the composition (10) at operating temperatures greater than about 2000 Kelvin. The composition (10) includes a first region (12) and a second region (14) and is operable to suppress or reflect photons having a wavelength greater than about 700 nm and to emit or transmit photons having a wavelength between about 400 nm and about 700 nm.