| 摘要 |
PURPOSE:To improve linearity of oscillation frequency to input current and to reduce secondary distortion involved in modulation in an FM converting circuit using a monostable multivibrator by providing a pair of corrector resistances in place of a transistor for setting voltage variation width. CONSTITUTION:Voltage drop generated alternately in corrector resistances R6, R7 connected to transistors (TR) Q8, Q9 that form a TR differential switch 6 is made differential voltage and impressed to the base of TRs Q1, Q2 that form a monostable multivibrator 2. Voltage variation width is set according to a current value of a constant current TRQ10 connected to the differential switch 6. Thus, the parasitic capacity incidental to the TR for setting voltage variation width can be excluded, and the linearity of oscillation frequency to input current is improved, and the secondary distortion involved in modulation can be reduced. |
