| 摘要 |
PURPOSE:To make it hard to be influenced even when a change is made by an ambient temperature by amplifying the difference between the outputs of two low frequency area signal passing means by a direct-current amplifying means, comparing the level of its output based on a reference voltage by a voltage comparing means detecting the synchronization/asynchronization of signals. CONSTITUTION:When two outputs (1) and (2) are sent to a direct-current amplifying means 23a through low frequency area signal passing means 21a and 22a corresponding respectively and the difference between their direct-current components is obtained and amplified by the direct-current amplifying means 23a, the level of a large difference appears when they are asynchronous, and the difference does not appear and it becomes nearly zero-level when they are synchronous. This is discriminated by a voltage comparing means 24a and the synchronization is detected. Thus, a synchronization circuit hard to be influenced by the fluctuation of the ambient temperature can be realized. |
