| 摘要 |
PURPOSE:To make the duty of an output pulse of a frequency doubler to about 50%, by making direct current for output pulses of the frequency doubler and applying it to a variable delay circuit. CONSTITUTION:An input pulse f1 and an output pulse f1d of a variable delay circuit 1 are applied to an exclusive logical sum circuit EX to obtain a double frequency pulse f2. The logical product between the pulses f2 and f1 is taken out from a gate G and smoothed at a smoothing circuit 2. A DC voltage in which the duty of the input pulse f2 from the gate G is taken out from a voltage comparison circuir A, the resistance of an FETQ is varied with this voltage to change the delay time, resulting that the duty of the pulse f2 is at almost 50%. |
