During start-up (t = 0) the input only sees a short circuit due to the bulk capacitor. Immediately after switch is turned on there is a large current spike (inrush current, i = C x dV/dt, since t is almost 0 and i becomes very very large). At this time, the bulk capacitor is starting to charge. And at this time, there is still no sufficient voltage for the soft start circuit to be activated. So how can the soft start circuit work?
Because it's in the primary.
A way to control the inrush current is to put a thermistor in series (this is not a soft start circuit) with the AC line. .
Yes yes yes, that's what the book said.
However, it is still not enough to significantly reduce the inrush current. As such, there is still possibility of fuse blowing up
The fuse or the thermistor itself can blow up too.
A way to reduce inrush current is a thermistor. The article discusses the disadvantages of a thermistor in a power amplifier. How about other equipments? Still it can reduce inrush current - this is the point.
We are talking about audio power amplifiers, yes? Of course it can, NTCs are designed to do specifically that.
Me, I, Myself, Mark or Rod didn't say it does not, but not for an equipment such as an audio power amplifier that has varying current during normal operation. That is the point.
However, if you are happy using it in real life, not on paper, then do so with indulgence.
The question is how does the electronic soft start circuit work to reduce inrush current where there is barely enough supply voltage to turn it on during start-up?
Because the electronic soft start does not rely on the supply voltage of the charging caps. So it doesn't matter if t=0 or if e=mc
2, the soft start doesn't care - it's designed to be a separate entity.
I am sure you are already well aware of this.
