This paper provides a method of changing the effective value of the capacitor for starting a single phase induction motor starting. This capacitor is connected in series with the auxiliary winding. Its effective value can be controlled by static switches in parallel with the capacitor through a series of pulses. The focus was on finding ways of obtaining the best effective capacitor during starting condition through computer simulation software using (Matlab). By using this method, only one capacitor is used for both the starting and running conditions and a similar starting performance can be obtained when compared with the conventional method using two capacitors. The computer simulation results are validated by building a laboratory model and comparison of results.
Key words: single phase induction motor, switched capacitor, variable capacitor, starting conditions.