| 摘要 |
PURPOSE:To obtain a fading device which can be suitably applied to the stereo device or the like using a reduced amount of dispersion for the ON time constant of the photo coupler and interms of both the fade-in and fade-out actions. CONSTITUTION:In the normal state, photo coupler 10 and relay 11 are operating, and the input signal sent from terminal 8 is delivered to terminal 9 via the contact of relay 11 with no attenuation. For the fade-out action, voltage A of terminal 14 is attenuated gradually along with voltage B of terminal 15 being given the rise gradually. At the same time, the signal voltage supplied from terminal 8 is divided by the resistances of couplers 10 and 12 to be delivered to terminal 9 when relay 11 is turned off. The variation of the output signal is decided almost by the resistance change of coupler 12, i.e., the ON time constant. When the signal output of terminal 9 features almost zero, relay 13 is driven to turn the output zero completely. The action of the fade-in time is just opposite to the action mentioned above. |
