摘要:
An electrothermal heater mat for anti-icing or de-icing of a helicopter rotor blade or other aerodynamic surface comprises a substrate, such as a flexible polyimide sheet, bearing tracks of a material of selected electrical resistivity, these tracks being formed by printing onto the substrate with a thermosetting ink loaded with electrically conductive (e.g. carbon) particles. Electrical bus bars/terminals for the supply of electrical energy to the resistive tracks may also be printed, using an ink loaded with particles of higher conductivity material such as copper or silver.
摘要:
A deicer comprises a skin heating device immediately subjacent an outer skin overlying an apex of a leading edge, and a skin deflection device immediately subjacent the outer skin chordwise aft of the apex. The skin heating device prevents the formation of ice over the apex and the skin deflection device deflects the outer skin to expulse ice formed chordwise aft of the apex. A controller controls the heating and deflection cycles to minimize power consumption of the deicer.
摘要:
A number of resistive elements are incorporated into the aerofoil in the vicinity of its leading edge. Each of the resistive elements is electrically connected to the other resistive elements at its distal end and is fitted at its proximal end with means of connection to an electrical power supply. The resistive elements are split between a first set that includes at least two resistive elements and a second set that includes at least one resistive element. In service, the resistive of the first set are powered in turn, while each resistive element of the second set acts as a return path for the electricity and is powered continuously or almost continuously.
摘要:
Method and apparatus for covering a free-standing body with a uniform glow discharge plasma, particularly at atmospheric pressure. The method may be used to provide a body coated with such a plasma, and also to treat a workpiece.
摘要:
A de-icer for a structural member of an aircraft is provided. The de-icer includes first and second heaters having first and second electrically conductive strips, respectively. The first and second conductive strips are configured to form first and second marginal portions, respectively. The first and second heaters are positioned relative to each other such that the marginal portions are overlapped.
摘要:
An AC power control apparatus including a power circuit for supplying an AC current to a load, and a circuit connected to a power supply, for initiating energization of the load at a zero-cross point of an AC current waveform. A control circuit for controlling the change of energization time between a current turn on time to a current turn off time in units of AC waveform cycles, and a detector for detecting an AC zero level. From a given polarity of the AC current waveform, the initiating energization of the load and deenergization of the load at a zero-cross point of the AC current waveform is from the same polarity as the given polarity of the AC current waveform.
摘要:
An all solid state timer-controller for the timed, sequential application of electrical current to loads within a circuit at high amperage, the circuit finding utility in the application of electrical current to de-icers employed aboard aircraft.
摘要:
An AC power control apparatus includes a plurality of power supply circuits for generating powers having different maximum values, a switching circuit for, after an AC current is continuously set in a desired turn on control state, alternately selecting a first power supply circuit used until that time and a second power supply circuit for supplying a power approximating a power supplied to a load at that time from the plurality of power supply circuits, a turn on time control circuit for gradually shortening a turn on time of the first power supply circuit while gradually prolonging a turn on time of the second power supply circuit until the turn on time of the second power supply circuit corresponds to the entire period, and a circuit for changing the turn on time of the power supply circuit in units of periods of the AC current.
摘要:
A switching system for sequential connection of a plurality of loads to an alternating current supply comprises a computer for generating switch selection data in the form of serial bits along a single line to a distributor arrangement which decodes the selection data and provides control signals to switch devices which connect the loads to the supply. The distributor arrangement includes a circuit for inhibiting supply of the control signals to the respective switch devices unless the voltage of the supply phase connected by the device is substantially zero. Additionally the control signals are time-advanced with respect to the zero voltage conditions so that the switch devices can be placed in states in which they can connect a load before disconnection of a preceding load.
摘要:
A device for preventing ice formation on parts of aircraft-support surfaces (wings or aerofoils), propellers, rotor blades or the like-comprises electrical resistance heaters embedded in a shell of thermally conducting material (e.g. aluminium sheet or moulding) sheathing the aircraft part. Thermally insulating, thermally conducting and electrically insulating layers may be provided within the shell. The heaters, or some of them, may be controlled by a temperature sensor in or on the shell.