| 摘要 |
PURPOSE:To remove the fluctuating phenomenon of output by providing a controlling circuit to adopt an operation detecting level for a detecting level when the output of a level detecting circuit is a non-operation signal and to adopt a return detecting level when the same is an operation signal. CONSTITUTION:Two AC inputs are respectively passed through square wave converting circuits 1 and 2 to be supplied to an integration circuit 6 through an addition circuit 3, a rectifying circuit 4, and a zero shift circuit 5, and then fed to a level detecting circuit 7 to output an operation signal when the output of the integration circuit is above a certain detecting level or a non-operation signal when below. The output of the level detecting circuit 7 is discriminated by a control circuit 8 for adopting an operation detecting level for the detecting level of the level detecting circuit 7 when the output is an non-operation signal, or an return detecting level when an operation signal. This construction serves to eliminate the fluctuating phenomenon of output given in a transitional state from non-operation to operation or from operation to non-operation. |
