AC electrical
Terms
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- Ac frequency for most aircraft is
- 400 hz or 400 cycles per secound
- what is a sine wave
- a sine wave is a wave prouduced by a rotary generator one cycle begins at zero and ends at 360.
- phase
- when a sine wave crosses the zero line at the same time, the voltage and current are said to be in phase , in other words both voltage and current follow the identical sine wave.
- phase angle
- when certain circuit components cause a phase shift between the voltage and current, the amount of shift is referd to as the phase angle or the angle whose cosine is the powerfactor.
- alternating current
- ac current is current flow which continually changes its value and periodically reverses direction
- direct current
-
dc electricity is nonvarying
in nature, the amplitude of volatage and current remain stedy. - apparent power
- when both current and voltage are given in effective values the product of those effective values is called aparent power
- true power
-
true power is the actual ac power in current when phase is taken into acount
ExIxpowerfactor= true power - resistive circuits
- circuits containg componets such as lightbulbs,heaters,and compostion restistors are considerd to be resistive circuits
- inductance
- is a measure of the amount of magnetic flux produced for a given electric current.
- inductance reactacne
- inductave reactince is the oppostion to the flow of alternating current cause by a generation of back voltage
- transformer
- a transformer allows the values of ac voltage and current to be changed through the use of mutual inductance.
- capacitors
- a capacitor sometimes called a condensor is a device that stores electrical energy in the electrostaic fields that exist between two conductors that are seperated by an insulator or dielectric.
- farads and columbs
- a capacitors ability to store an electrical charge is mesured in farads. one farad is the capacity required to hold one coloumb of electricity under a force of 1 volt
- switches
- off is down on is up