大师作文网555多谐振荡电路的周期计算公式是多少?
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555多谐振荡电路的周期计算公式是多少?
f = 1 / T = 1.44 / (R1 + 2R2)*C
再问： 怎么推导的？
再答： The external capacitor charges through R1 + R2 and discharges through R2. Thus the duty cycle may be precisely set by the ratio of these two resistors. The capacitor C charges and discharges between 1/3 VCC and 2/3 VCC. The charge time (output high) is given by: t1 = 0.693 (R1 + R2) C And the discharge time (output low) by: t2 = 0.693 (R2) C Thus the total period is: T = t1 + t2 = 0.693 (R1 +2R2) C The frequency of oscillation is: f = 1 / T = 1.44 / (R1 + 2R2)*C
再问： 怎么推导的？
再答： The external capacitor charges through R1 + R2 and discharges through R2. Thus the duty cycle may be precisely set by the ratio of these two resistors. The capacitor C charges and discharges between 1/3 VCC and 2/3 VCC. The charge time (output high) is given by: t1 = 0.693 (R1 + R2) C And the discharge time (output low) by: t2 = 0.693 (R2) C Thus the total period is: T = t1 + t2 = 0.693 (R1 +2R2) C The frequency of oscillation is: f = 1 / T = 1.44 / (R1 + 2R2)*C