FREQUENCY SWITCHING CIRCUIT

摘要

PURPOSE:To obtain easily various types of frequency switching circuits through the simple digital circuit constitution by fetching the switching output of cut-off frequency f0 by means of the change/discharge circuit which is controlled by the gate circuit. CONSTITUTION:Monostable multivibrator 1 synchronizes with the input pulse signal of duty D and then generates the 1st pulse signal featuring pulse duration T1 identical to the pulse duration of the pulse signal of duty D featuring the same repetitive frequency as cut-off frequency f0. While monostable multivibrator 2 generates the 2nd pulse signal featuring pulse duration T2 of T1>T2 in response to the rear edge of the 1st pulse signal and then supplies the input pulse signal and the 2nd pulse signal through AND gate 3. Using charge/discharge circuit 4 controlled by the output of gate 3, the switching output of the frequency f0 is fetched. In such way, various types of frequency switching circuits can be obtained easily through the simple digital circuit constitution.