| 摘要 |
<p>PURPOSE:To obtain an highly accurate oscillated frequency by comparing an output of a comparison voltage integration means with a reference voltage and decreasing the integration value more rapidly than increasing it thereby keeping the comparison voltage integration means to a prescribed accuracy. CONSTITUTION:When a comparison voltage decrease means E is turned off at periods T0-T1 and a voltage of a capacitor AC0 of the comparison voltage integration means A reaches an upper limit reference voltage SU at a prescribed time constant T1, the means E is turned on to discharge the electric charge, a changeover means C switches a reference voltage S to a lower limit reference SD, the voltage reaches the reference SD or below at a time T2 after 0.1mus and a comparison means D reaches a high level. The means C switches the reference voltage S into the upper limit reference SU and the means E is turned off. The comparison voltage S is increased to the voltage SU from a time T3 with a delay of the forward voltage drop of a FET. The charging/ discharging is repeated and a rectangular wave is oscillated at a prescribed frequency from the comparison means D. Through the constitution above, the accuracy of the comparison voltage integration means is kept to a prescribed value and the oscillation with high accuracy is obtained.</p> |
