yes Matlab is required . A circuit consists of a Thévenin equivalent source (Vth
ID: 2291322 • Letter: Y
Question
yes Matlab is required
. A circuit consists of a Thévenin equivalent source (Vth and Rth) and a resistive load (Rload). Write a script which prompts the user to enter values for Vth and Rth, then computes and plots both power delivered to the load and efficiency as a function of the load resistance. The efficiency is defined as power delivered to the load divided by power supplied by the voltage source (power dissipated by Rth is considered "lost" power). Plot both results on the same plot using yyaxis to get independent y-axes. Add a legend to identify each result. Use a linear x-axis for the load resistance value and choose the range of x-axis values so that the maximum power point is always shown. (Hint: the range of x-axis values will need to depend on the value of Rets and we know (or should know) from circuits class that the max um will occur when the resita ce values are equal.) Include the values of th and Rh in e plot le ( ie ay o do h to : a e·n u l : p I r matv 1 omb na tim d tr and 'I J, then pass that string to title). Test your script with the the following input values: (a) 15 V and 33 2 b) 120 V and 8.2 k2, and (c) one set of values which you choose. As always, title the plot, label the axes, and include units. Repeat the above except use a logarithmic x-axis. Choose beginning and ending values to go from approximately one decade below to approximately one decade above the maximum power point. For the lower limit this can be accomplished by taking the log of the resistance, subtracting a number slightly less than one, rounding down to the nearest integer value, and using that as an argument to logspace). e.g. r- logspace ( floor(log10(Rth)-0.8), ...) ; a similar method can be used to obtain the upper limit. Interpret "approximately" loosely and experiment with variations of this to find a function that produces reasonable x-axis values regardless of the Thévenin resistanceExplanation / Answer
First calculate the input power (Pin), Output Power (Po) and Efficiency (n)
Pin = Vth2/Rth
Po = Vo/RL
Vo = VthRL/(Rth+RL)2 (Use voltage division method)
Therefore Po = ((VthRL/(Rth+RL))2/RL = VthRL/(Rth+RL)2
Efficiency (n) = Po/Pin = RthRL/(Vth*(Rth+RL)2
Use the below code to plot linear graph
prompt = 'Enter the value of Vth';
Vth = input(prompt)
prompt = 'Enter the value of Rth';
Rth = input(prompt)
Pin = Vth^2/Rth;
Po = ((Vth*RL/(Rth+RL))^2/RL = Vth*RL/(Rth+RL)^2;
n = Rth*RL/(Vth*(Rth+RL)^2;
yyaxis left
plot(RL, Po)
yyaxis right
plot(RL,n)
ylim_max = Rth+10;
ylim([0,ylim_max])
xlabel('RL (ohms)') % x-axis label
ylabel('Po (watts) and n') % y-axis label
formatSpec = 'Graph of Po and n Vs RL where Vth, Rth is repectively: %d %d';
title(sprintf(formatSpec, Vth, Rth))
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