www.pudn.com > matlab±à³Ì.zip > calc_power.m, change:1999-03-08,size:1114b

%  Script file: calc_power.m 
% 
%  Purpose:  
%    To calculate and plot the power supplied to a load as  
%    as a function of the load resistance.  
% 
%  Record of revisions: 
%      Date       Programmer          Description of change 
%      ====       ==========          ===================== 
%    12/01/98    S. J. Chapman        Original code  
% 
% Define variables: 
%   amps      -- Current flow to load (amps) 
%   pl        -- Power supplied to load (watts) 
%   rl        -- Resistance of the load (ohms) 
%   rs        -- Internal resistance of the power source (ohms) 
%   volts     -- Voltage of the power source (volts) 
 
% Set the values of source voltage and internal resistance 
volts = 120; 
rs = 50; 
 
% Create an array of load resistances 
rl = 1:1:100; 
 
% Calculate the current flow for each resistance 
amps = volts ./ ( rs + rl ); 
 
% Calculate the power supplied to the load 
pl = (amps .^ 2) .* rl; 
 
% Plot the power versus load resistance 
plot(rl,pl); 
title('Plot of power versus load resistance'); 
xlabel('Load resistance (ohms)'); 
ylabel('Power (watts)'); 
grid on;