The auxiliary power unit APU has its own AC generator that ?
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Source: Telepilote theorique examen 25
A magnetic circuit breaker is ?
The advantages of alternating current on board an aircraft are 1 simple connection2 high starting torque3 flexibility in use4 lighter weight of equipment5 easy to convert into direct current6 ?
On board present aircraft batteries used are mainly cadmium nickel their advantages are 1 low risk of thermal runaway2 high internal resistance hence higher power3 good charging and discharging capability at high rating4 wider permissible temperature range5 good storage capability6 sturdiness owing to its metal casing7 electrolyte density remains unchanged during charging the combination of correct statement A protection system that has a quick tripping response. The terminal voltage remains substantially constant at about 1 2 volts throughout most of discharge due to its low internal resistance it also capable of supply high current during its discharge cycle low current during recharging without violent fluctuations of terminal voltage nicad batteries have a low thermal capacity heat generated in certain conditions faster than it can dissipate so causing rapid increase in temperature this has effect of lowering effective internal resistance thus allowing an ever increasing charging current which unless checked leads to total destruction of battery. 
A static inverter powered Direct current on input alternating current output. an inverter a unit used to convert dc into ac dc to ac inverter ac to dc rectifier. 
The voltage regulator of a dc generator connected in Series with shunt field coil. On a dc generator voltage regulation achieved changing voltage in voltage coil which changes carbon pile pressure which changes current in shunt field the voltage regulator connected in series with shunt field coil. 
During start of an engine fitted with a brushless ac generator with no commutator rings generator activated A set of permanent magnets. On a dc generator voltage regulation achieved changing voltage in voltage coil which changes carbon pile pressure which changes current in shunt field the voltage regulator connected in series with shunt field coil. Question 25-8
The type of windings commonly used in dc starter motors are A set of permanent magnets. Dc motors are classified as to ways in wich their field excitation circuits are arranged (series wound shunt wound compound wound) the series wound motors have their field armature windings in series with each other so same current flows through both adding them together these motors have a high starting torque especially as in initial stages there little back emf so all current used in them they are commonly used as starter motors. Question 25-9
The power output of a generator controlled Varying field strength. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-10
A relay A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-11
The voltage of a fully charged lead acid battery cell A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-12
The capacity of a battery given in A magnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-13
A relay An electromagnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-14
The most widely used electrical frequency in aircraft An electromagnetically operated switch. The only practical method of controlling output voltage of a generator to control strength of magnetic field controlling current flow in a coil wound around magnetic pole pieces (field coil or field winding) control of current flow achieved a voltage regulator the voltage regulator senses output voltage of generator or alternator adjusts field current to maintain correct output voltage irrespective of generator speed or electrical load. Question 25-15
If electrical load of an ac generator providing a constant output voltage increases voltage regulator will Increase intensity of excitation current. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-16
The so called 'hot buse or 'direct buse are Directly connected to battery. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-17
The reason using inverters in an electrical system To change dc into ac. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-18
The function of a constant speed drive csd to ensure That generator produces a constant frequency. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-19
A bus bar A distribution point electrical power. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-20
A csd of an ac generator may be disconnected in flight the primary reason s disconnection are Low oil pressure and/or high oil temperature of generator drive. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-21
A csd unit which has been disconnected in flight May be reset on ground only after engine shut down. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-22
Because of input/output relationship of an or gate it often referred to as May be reset on ground only after engine shut down. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-23
Connecting two 12 volt 40 ampere hour capacity batteries in series will result in a total voltage and capacity respectively of 24 volts 4 ampere hours. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-24
When a conductor cuts flux of a magnetic field An electromotive force (emf) induced in conductor. The output regulated varying current to field windings the voltage regulator senses alternator output adjusts field current when a voltage rises above a set value (typically 115 5 v) the current cut off around 2000 times a second the voltage regulator there to stop battery being overcharged or system being overloaded. Question 25-25
In order that dc generators will achieve equal load sharing when operating in parallel it necessary to ensure that Their voltages are almost equal. When two dc generators are operating in parallel control of load sharing achieved an equalising circuit which in conjunction with voltage regulators varies field excitation current of generators. Question 25-26
The purpose of a voltage regulator to control output voltage of Generator at varying loads speeds. For dc generators voltage regulation achieved changing voltage in voltage coil which changes carbon pile pressure which changes current in shunt field this then the reactive load (wasted power) that adjusts energising current the same principle applies in ac generators (alternators) but they use solid state circuitry. Question 25-27
A current limiter fuse in a dc generation system used to Allow a short term overload before rupturing. A fuse a deliberately weak part of a circuit that designed to fail if a problems occurs current limiters are like fuses but with a much higher melting point so that a higher overload current can be carried (they allow a short term overload) they will limit current to a predetermined value are used heavy duty circuits. Question 25-28
A 3 phase ac generator has 3 separate stator windings spaced at Allow a short term overload before rupturing. A fuse a deliberately weak part of a circuit that designed to fail if a problems occurs current limiters are like fuses but with a much higher melting point so that a higher overload current can be carried (they allow a short term overload) they will limit current to a predetermined value are used heavy duty circuits. Question 25-29
A csd unit normally provided with means of monitoring during flight Oil temperature pressure. A fuse a deliberately weak part of a circuit that designed to fail if a problems occurs current limiters are like fuses but with a much higher melting point so that a higher overload current can be carried (they allow a short term overload) they will limit current to a predetermined value are used heavy duty circuits. Question 25-30
The phase relationship between two unparalleled ac generators Oil temperature pressure. A fuse a deliberately weak part of a circuit that designed to fail if a problems occurs current limiters are like fuses but with a much higher melting point so that a higher overload current can be carried (they allow a short term overload) they will limit current to a predetermined value are used heavy duty circuits. Question 25-31
Assuming a csd fault indicated csd should be disconnected Provided engine running. The function of a constant speed drive (csd) to ensure that ac generator produces a constant frequency in case of csd fault you must disconnect it (if engine running if not since ac generator not rotating you don't need to disconnect it) a csd unit which has been disconnected may be reset on ground only after engine shut down. Question 25-32
Ac generators operated in parallel must have same Provided engine running. Two ac generators operated in parallel must be not only at same speed (voltage) but also same phase to be paralleled. Question 25-33
The measured output power components of a constant frequency ac system are Provided engine running. Two ac generators operated in parallel must be not only at same speed (voltage) but also same phase to be paralleled. Question 25-34
'frequency wil in relation to a ac generation system means generator Output frequency varies with engine speed. Two ac generators operated in parallel must be not only at same speed (voltage) but also same phase to be paralleled. Question 25-35
When ac voltage across a capacitor kept constant and frequency increased current through capacitor will Output frequency varies with engine speed. Capacitive reactance when frequency tends to zero current magnitude almost equal to zero at contrary when fequency high this the magnitude of voltage which tends to zero we are talking about capacitive reactance xc expresses in ohm. Question 25-36
In an aeroplane fitted with a constant frequency ac power supply dc power obtained from a Transformer rectifier unit (tru). Capacitive reactance when frequency tends to zero current magnitude almost equal to zero at contrary when fequency high this the magnitude of voltage which tends to zero we are talking about capacitive reactance xc expresses in ohm. Question 25-37
On an aeroplane using ac as primary power supply batteries are charged in flight from A transformer rectifier unit. Capacitive reactance when frequency tends to zero current magnitude almost equal to zero at contrary when fequency high this the magnitude of voltage which tends to zero we are talking about capacitive reactance xc expresses in ohm. Question 25-38
Immediately after starting engine s with no other electrical services switched on an ammeter showing a high charge rate to battery Would be normal is only cause concern if high charge rate persists. If engine was started electrically using battery there would have been a significant drain on battery the ammeter shows a charge after start up to replenish energy just drained from battery. Question 25-39
Circuit breakers protecting circuits may be Used in ac dc circuits. If engine was started electrically using battery there would have been a significant drain on battery the ammeter shows a charge after start up to replenish energy just drained from battery. Question 25-40
The function of a csd in an ac generating system to Drive generator at a constant speed. If engine was started electrically using battery there would have been a significant drain on battery the ammeter shows a charge after start up to replenish energy just drained from battery.
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