| 摘要 |
PURPOSE:To prevent the generation of noises and also prevent the deviation in duty ratio by giving the rise in transmit pulse a gradient, and adjusting the resulting deviation in duty ratio through an integrating circuit and a discharging circuit. CONSTITUTION:A transmission control pulse signal is inputted to the 1st integrating circuit 1, whose output is inputted to a transistor TRTr3 through an inverter IC1 to turn on and off the TRTr3. When an H-level signal is inputted to the TRTr3, its collector potential does not rise up to the level H soon because a capacitor C2 is connected between its collector and the ground, and the capacitor is charged with the time constant determined by a resistance R5 and the capacitor C2. In this case, the capacitor C2 is discharged on constant current basis through diodes D1 and D2, so the potential rises linearly. The charged capacitor C2 is discharged instantaneously because a TRTr7 is turned on through the inverter IC1. Thus, a signal which does not vary in duty ratio as compared with the transmission control pulse signal is obtained.
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