| 摘要 |
Disclosed is a 1/2H removing circuit for NTSC signal including a transistor(Q4) which is driven by the operation of a transistor(Q2) driven by a synchronous signal input, transistors(Q1,Q27) which are driven by the output of the transistor(Q4), transistors(Q9,Q11) which are driven by the transistor(Q27), transistors(Q8,Q14,Q21) which are driven by the output of the transistor(Q9), a resistor(RO1) and a capacitor(C2) that are charged and discharged, a transistor(Q21) which is driven by the charge/discharge voltage of the resistor(RO1) and the capacitor(C2), and transistors(Q18,Q19) which are driven by the transistors(Q21,Q2) and output horizontal frequency(FH). Thus, the width of the horizontal frequency is adjusted by using charge/discharge time constant.
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