Finding delay angle ,Vrms, Irms using AC voltage/ load resistor

Click For Summary
SUMMARY

The discussion focuses on calculating the RMS voltage, RMS current, and average power in a light dimmer circuit connected to a 240V AC supply. The relevant formula used is P = Vrms² / (2∏R (∏ - α + 1/2sin(2α)), where R represents load resistance and α is the delay angle. The participant successfully derived the RMS voltage as 169.7V by using the equation Vrms = 240/sqrt(2). The calculations for the delay angle α were also addressed, confirming the participant's understanding of the topic.

PREREQUISITES
  • Understanding of AC circuit theory
  • Familiarity with RMS voltage calculations
  • Knowledge of power equations in electrical circuits
  • Basic grasp of trigonometric functions related to phase angles
NEXT STEPS
  • Study the derivation of RMS voltage in AC circuits
  • Learn about the effects of delay angle α on power consumption
  • Explore load resistance calculations in light dimmer circuits
  • Investigate the relationship between average power and RMS values in AC systems
USEFUL FOR

Electrical engineering students, circuit designers, and anyone involved in the analysis of AC circuits and power consumption in dimmer applications.

pokie_panda
Messages
35
Reaction score
0

Homework Statement



From the average power consumed by the lamp in a light dimmer circuit connected to 240V AC main,
What is the expression for RMS voltage,
calculate the range of values of the delay angle α,(i)RMS voltage (ii)RMS current in the lamp, (iii) the average power if its nominal ratings are 240 V AC, 40 W.

Homework Equations



P=Vrms^2/2∏R (∏-α+1/2sin(2α))
R= load resistance
Vrms= amplitude of supply voltage
α=delay

The Attempt at a Solution


This is where I'm not sure ,
if we have the nominal ratings of 240V AC and 40 W,
we know that
Vrms = 240/sqrt(2)
=169.7
Then from the equation above solve for α
 
Last edited:
Physics news on Phys.org
Don't worry i figured it out
 

Similar threads

Controlled rectification question
  • · Replies 6 ·
Replies
6
Views
3K
Root-mean squared values and a.c. emf
  • · Replies 5 ·
Replies
5
Views
3K
Find the maximum voltage of an AC generator
  • · Replies 1 ·
Replies
1
Views
5K
Find the average power delivered by the voltage source
  • · Replies 8 ·
Replies
8
Views
12K
PSPICE rectified AC to voltage regulator
  • · Replies 18 ·
Replies
18
Views
5K
Engineering Load resistor in circuit: Find the no-load voltage.
  • · Replies 9 ·
Replies
9
Views
9K
Engineering AC Circuit; find average and reactive power to load (and load V and I)
  • · Replies 8 ·
Replies
8
Views
5K
Three phase AC concepts and problems
  • · Replies 2 ·
Replies
2
Views
6K
What is the Power Dissipated in a Bulb with a Set Firing Angle?
  • · Replies 3 ·
Replies
3
Views
4K
Engineering Find power of resistor and source in AC circuit
  • · Replies 2 ·
Replies
2
Views
2K