Electronics

Farat sagt wie viel Platz es hat

Xl = Spuhle => wird grosser und der Strom wird kleiner

Split Bus System => Nach dem T/O werden alle miteinander conected => Sobald Genie 1/2 und 3/4 die selbe Frequency + Voltage haben wird der SSB geschlossen ==> BTR können den contact erst schliessen, wenn Gen 1 und 2 die selbe Frequency and Voltage haben

BTR and GR => Beides öffnen um den Gen 3 (Gen Bus 3 braucht ja keinen Strom mehr) und tie bus 2 zu schützen,

Generator Controll Unit stellt fest, ob Gen online geht

Nur das Magnet Feld im Innern dreht sich

Jetzt gibt es Poles und nicht mehr nur 2 => Synchronous speed which is half that of a 2 pole rotor at the same supply frequency

(Frequency * 60) / pole pairs = RPM

Ein Transformator wandelt eine Eingangs-Wechselspannung, die an einer der Spulen angelegt ist, in eine zweite, Ausgangs-Wechselspannung um, die an der anderen Spule abgegriffen werden kann

Ein Transformator wandelt eine Eingangs-Wechselspannung, die an einer der Spulen angelegt ist, in eine zweite, Ausgangs-Wechselspannung um, die an der anderen Spule abgegriffen werden kann ==> Step up and step down

beim Touch down => Im Reifen hat es ein Kupfergewebe

Q = I x t Colom => wie viel das tatsächlich drin ist => Strom x Zeit ====> Farat: wie viel das theoretisch Platz haben

Theoretisch ist er nie ganz geladen ==> 5 cicels

1. Vergleiche Bild 2. 2.0 V 3. 12 cells in Serie => 24 V (Gefahr: wenn eine Celle kaputt geht, ist due ganze Batterie kaputt) 4. 2.4 - 2.7 V

1. vgl. Bild 2. 1.2 V 3. 20 cells in Serie = 24 V (eine Kaput, ganze Batterie kaputt) 4. ca. 1.4 V

1. Electric heating => AC

2. lightining => AC

3. Mechanical Power => AC (Pumps, valves, motion)

4. Electrical Devices => AC/DC (Computers, sensors) 

==> AC consumers are 95% of the total electrical energy

AC: changes urs polarity

DC: constant & flows in one direction only  => to a given maximum and back to zero in one direction before reaching another maximm 

The position of a point in time within the waveform cycle => A complete cycle is defied as 360 degrees of phase

the number of cycles per second => it is measured in Hertz ===> constant frequency: 400 HZ frequency wild: 370 to 770 HZ f= 1/T

The change in phase of a periodic signal in horizontal shift with respect to a reference phase => refers always to phases with the same frequencies

\(R(Ohm) = {P * I \over A}\)

p= Specific resistance

I= Length of teh conductor 

A= Cross section area or the conductor 

the voltage induced into an indicator by a fluctuating magnetic field (Spuhle L ) is always in opposition to the voltage at the supply source => this opposition voltage delays the current flow

==> X_L \( = {W * L}\)

W = angular frequency (2 piii * f)

L= Inductivity 

The capacitor (C) will charge up first in one direction and then in the other => The current reaches its max. value of 90 degrees before the voltage over the capacitor reaches its max.

==>X_C \( = {1 \over w * C}\)

w = Angular frequency (2piii * f) 

C = Capacity 

phase shift = Angle between the voltage and the current vector ==>In connection with the true voltage U_R whose vector must be rectangular to the reactive voltage, a resultant voltage closes the triangele (Phytaguras) => So calles apparent voltage U 

True Power P: is converted z.B. into heat or motion  P = U * I 

Reactive Power Q: builds up electric or magnetic fields in capacitors or coils  => As soon as the field collapses the energy stored in the field is deivered back to the power source as reactive power   Q = U * I 

Apparent Power S: the geometric sum of true and reactive power (P + Q)  S = U * I 

the ration between true power and apparent power is called power factor => power factor = reactive power => Cos = True Power / Apparent Power

Is driven by the main engine   or

1. Auxiliary Power Units (APU) 

2. batteries (charged by the generators) => Output is DC

3. Ram Air Turbine 

4. external power on ground 

rotating DC excited pole wheel in at least three stator coils, mounted at an angle of 120 degrees ==> All coils are connected to one another by their final parts

The three stator windings can be connected in either a :

1. Star configuration  => the output power of generators in aircraft are always connected in a star configuration 

2. Delta configuration 

On of each phase winding is connected to a common point called NEUTRAL N or STAR POINT

=> The other end of each winding connects to output terminals distributing AC power if different phases (120 phase shift)

==> Output voltages: Phase voltage = 115 V          LIne volatge = 200 V 

a) the availability of two different voltages

b) The generator can feed unbalanced loads

c) Easy access to the phase voltages

==> When a three phases start connected generator feeds a balanced load, the net current of all phases is zero 

with no common or neutral point ==> The Phase and Line Voltages are the same by the Delta connection

The voltage in every coil of aircraft AC generators is 115 V and this is the so-called Line-to-neutral voltage or line -to-phase voltage (U_PH) 

The volatge between two phases (A-B, B-C or C-A) is calles line-to-line (U_L) and amounts to 200 V AC 

==> The single coils is 115 V and the voltage between the two coils aîs always 200V 

1. The PM (Permanent Magnet) Generator 

2. The Exciter Generator 

3. The Main Generator 

The generator requires four pole pairs because the RPM of the Generator is 6000

f = p * (RPM/60)