# Chapter16-The Mercury Arc Rectifier¶

## Ex9-pg617¶

In [1]:
## Example16_9_pg617.sce
## Effect of phase control
## Theory of Alternating Current Machinery by Alexander Langsdorf
## First Edition 1999, Thirty Second reprint
## Tata McGraw Hill Publishing Company
## Example in Page 617

import math

## Given data

phi = 20.;
alpha1 = 30.;
alpha2 = 0.;

## Calculations

ans1 = (math.cos(phi*math.pi/(180.*2.))*math.cos(phi*math.pi/(180.*2.) + alpha1*math.pi/180.)*100.);
ans2 = round(math.cos(phi*math.pi/(180.*2.))*math.cos(phi*math.pi/(180.*2.) + alpha2*math.pi/180.)*100.);
Effect = (ans1/ans2)*100.;

print'%s %.2f %s'%("\n\nEffect of phase control here is to reduce the dc voltage to ",Effect," of the value it would have in the absence of phase control\n");

## Result
## Effect of phase control here is to reduce the dc voltage to 77.77 % of the value it would have in the absence of phase control


Effect of phase control here is to reduce the dc voltage to  77.77  of the value it would have in the absence of phase control