Abstract: A ringer circuit which generates a sine wave, where an amplified output of a transistor for oscillation is fed back to a base of the transistor. An output from an output transistors is a sine wave. When this sine wave output is supplied to a circuit for driving a ringer IC, in which the output is rectified and integrated, the current waveform appearing between input terminals of a rectifier is a sine wave, not in a pulse form. Therefore, the fluctuation appearing in the current waveform at the output of an integrator is insignificant, and the average current will increase. As a result, it is possible to drive a ringer IC regardless of a load (value of components in the integrator). Further, it is possible to drive a telephone set with only R and C. A ringing tone with less noise can be generated. Thus, a ringing tone can be generated regardless of the type of telephone set, without increasing the frequency of an oscillation output.