Rectified D.C contains a large amount of ripple components which may be filtered using a capacitor of suitable capacitance. A capacitor blocks D.C and allows A.C. Hence a capacitor should sop D.C components and allow A.C components of a rectified signal to pass through. This should be able o make a speaker (used in radios) vibrate. The vibration produces a faint humming sound which is totally different from that produced by a pure D.C source e.g. a battery. This circuit can be designed for low voltages like 6V, 9V and 12V rectified D.C. A quite different circuit with different characteristics can be designed using a half wave rectifier. In this circuit the characteristics of both a pure D.C source as well as a source having ripples can be found. This paper aims o depict he construction and behavior of such circuits.