555压控振荡器振荡周期计算公式的修正

The Correction on an Oscillating Period Calculating Formula of 555 Voltage Controlled Oscillator

由555时基电路组成的压控振荡器,经实验得出的ux-T曲线中有一个极小值,这和理论计算值有较大差异.分析了产生这种现象的原因是控制信号ux较小时,受放电管V的饱和压降uces影响所致,并对理论计算公式进行了修正.

The ux-T curve exists a minimum result,got from the experiments on voltage controlled oscillator made up of 555 timers,whereas the minimum result is different from the theoretical calculation.This paper analyses the causes about this strange situation,which is caused by the affection by saturation voltage drop of the discharge crystal triode V when steering order ux becomes a smaller calculation than a usual one.Then the paper corrects the former calculating formula.