| 摘要 |
PURPOSE:To obtain a prescribed period from the initial pulse outputted from an oscillation circuit by connecting a microcomputer control input directly to the gate of the oscillation circuit. CONSTITUTION:A point (2) of a monostable circuit 2 is connected to the input side (4) of a gate G3 in the oscillation circuit and a microcomputer control input terminal 5 is directly connected to the input side of a gate G4 in the oscillation circuit 4. When the microcomputer control input is in the 'L' level, the oscillation circuit 4 does not oscillate. When the microcomputer control input is turned to 'H', the circuit 4 is excited. The circuit 2 starts to operate at the decay of SYNC, a point (3) is electrostatically charged by a time constant based upon a capacity C2 and a variable resistor VR1, and when the potential exceeds the threshold of a gate, a point (1) starts to be discharged by a time constant based upon a capacitor C1 and a resistor R3. When the potential exceeds the threshold, the point (2) is turned from 'L' to 'H' and the oscillation circuit 4 starts to oscillate.
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