| 摘要 |
PURPOSE:To read always the frequency of the input signal to be measured up to a desired unit, by controlling the time during which the gate which transmits the pulse of the reference signal is opened in response to the frequency of the signal to be measured. CONSTITUTION:First the count value K0 obtained in the initial period T0 is measured by a counting circuit 4. The value K0 is fed directly to an operator 5 if it is larger than the value K that can assure the desired resolving power. Then the value K0 is displayed at a display 9. When the value K0 is smaller than the value K, the open time of an AND gate 2 is increased. Then an operation of dividing ratio is performed through a dividing ratio operator 6 to obtain the value larger than K. The selection of dividing ratio is carried out through a window comparator part 7. The input signal to be measured which is divided with the dividing ratio selected at the part 7 is fed to the gate 2 from a selecting circuit 3 to proceed to the next counting period T1. The value K1 counted at the circuit 4 is fed to the operator 5 to display the result of operation to the display. |
