To perform the normal control not depending on the power source voltage by measuring a power source voltage when the power supply switch is turned on, and then selecting the ON start power source voltage of transistor depending on such power source voltage.

The reference voltage V3 of a first comparator 2 is an operation voltage of a recovery processing circuit when the first power source voltage (V1) is used, while the reference voltage V4 of a second comparator 3 is an operation voltage of the recovery processing circuit when the second power source voltage (V2) is used. When the power source switch is turned ON, an output of the first comparator 2 is stored in a latch circuit 4 with an output pulse of a power source ON detecting circuit 1. With this output, an input is selected by a selector 5. When the power source voltage is V1, the recovery processing circuit is operated with an output of the first comparator 2, and, when the power source voltage is V2, the recovery processing circuit is operated with an output of the second comparator 3. As a result, troubles, which is caused by selection and setting mistake of the recovery processing circuit, can be prevented.