| 摘要 |
PURPOSE:To prevent a large transient response from being generated at the switching of active/spare system and to settle the response to a correct control value stably immediately by recording an integration value recorded in a register of a digital integration circuit of the active system to a register of a digital integration circuit of a spare system controlling the spare transmission system in parallel and revising the value. CONSTITUTION:A control signal is fed to each register by an active/spare switching control signal 200 in a control circuit 16, which reads the content of the register 108a at the active system, writes it to a register 108b of the spare system so as not to write the output of an adder 107b to the register 108b. Thus, the output of the digital integration circuit 109b of the spare system is always the same as the output of the digital integration circuit 109a of the active system and no large transient response is generated at the switching of the transmission system. When the spare transmission system is in use, the output of the adder 107b revises the register 108b and the content is fed to the register 108a of the active system conversely. Even if there is a difference of the characteristic between both the active and spare transmission systems, the transient response of the transmission output due to changeover is slight and a smooth changeover is attained. |
