Average RMS and Power Flashcards
What is the Peak value of the voltage
The maximum possible positive or negative value
What is the Peak to peak value of the voltage
Range between the minimum and maximum value
What is meant by the Average or mean value
Value you obtain if you smoothed the wave form
What is meant by the Root Mean Square value
Essentially a measure of the power in a resistive load
What is the integral to calculate the average value
X=1/T* (integral between 0 and T of x(t)dt)
What is the integral to calculate the RMS
X= 1/T*(integral between 0 and T of x(t)^2dt)
For a pure AC wave what is the RMS value equivalent to
Standard Deviation
What does the average value tell you bout steady current
How much steady current you need to pass through a component for the same amount of time as you pass a variable current, so that the same amount of charge gets transferred
What is the average power equal to
Pave=1/T *(integral between 0 and T of v(t)I(t)dt
What is the average power equal
Pave =Vdc*Idc
What are the 2 equations for average power in a resistive load
Pave=RIrms^2
Pave=v^2rms/R
At steady state current or Irms gives the same average power dissipation in a resistor as……???
The Varying current
R.M.S value is tells you how effective the wave is at what?
Dissipating power in a resistor
What is the equation for the RMS value of the current.
Irms= square root of (1/T*integral between 0 and T of I(t)^2 dt
What is the equation for the Vrms for a sine wave
Vrms=Vpk/square root 2
Is the equation for Vrms for a sine wave a general result
No, other waves have different RMS values
Why is the Mains value stated as an RMS value and what is the RMS value and Peak value
Because the RMS value tells you about power being dissipated which is what is paid for
Vrms= 230V
Vpk= 325V
What are the amplitude RMS values of Sin waves, Square Waves and Saw tooth functions
Sin waves= A/root 2
Square waves= A
Saw tooth waves= A/root 3
What is the Vrms for a square wave with an amplitude +-Vo
Vo
Full Wave rectification is the same as taking the…..
Absolute value (magnitude)
What is the equation for a fully rectified sin wave
V(t)=Vpk|sinwt|
What happens the frequency during rectification.
It is doubled
For full wave Rectification what are the limits of integration
0 and T/2
For a rectified sin wave what is the Vavg
Vavg=2/pi * vpk=0.64Vpk
What is the Vrms for a rectified sin wave
Vrms=1/root2 *vpk=0.71 Vpk
What must be true must be about Vrms and Vavg
Vrms is greater than or equal to Vavg
What effect does full wave rectification have on the RMS value
No effect so the Vrms of a full rectified wave is Vpk/root 2
What can be helpful when calculating averages
Symmetry
What portion of the Period of the wave do you need to consider for a triangle wave
T/4
For a square wave what is the Vr.m.s
Vr.m.s = Vpeak aka the amplitude of the square wave
What is the equation relating Vavg and Duty cycle
Vavg = DVon + (1-D)Voff
What is the equation relating Vr.m.s and duty cycle
Vr.m.s= square root of (DV^2on + (1-D)V^2off)
For half wave rectification of a sin wave What is the integral for the Vavg
Vavg=(1/T) x intergrall of (Vosinwt) dt btween 0 and T/2
For half wave rectification of a sin wave what is the Vr.m.s
Vr.m.s= Vo/2
For full wave rectification of a sine wave what are the equations for Vavg and Vr.m.s
Vavg = 2Vo/pi Vr.m.s = Vo/(root 2)
For a triangle wave how does the peak voltage relate to r.m.s voltage
Vpk = Vr.m.s x (root3)
