Re: Mains conditioners and power cables

Arfa Daily wrote:


* I'm having a bit of trouble with that one. A larger capacitance will certainly try to increase the * initial charge current over the first few cycles as the power supply comes up, which if allowed, * may exceed the peak forward current capability of the rectifier diodes. However, in a
* transformer derived supply, the effect will be mitigated by the natural current limiting effect of
* the transformer's secondary and to a lesser extent, primary, winding inductances. Any
* resistance in the windings, or in the form of surge limiter resistors, will also contribute to the
* charge current limiting.

* Once the capacitor is charged, the ripple will be reduced by the effectively lower source
* impedance of the increased value of capacitance. This effectively means that the capacitor is a * bigger bucket, better able to supply the load's current requirements, which haven't changed
* from when a smaller value was fitted. This, it only needs to do, of course, between cycle
* pulses from the rectifier. As the bucket won't drain down as far during these pulse gaps, it will * take less energy to fill the bucket back up, not more.


1.It will take exactly the same enery to "fill up" as the same amount has been removed by the amplifier running with the same current requirement.

2.However as the capacitance is higher, removing the same energy per cycle will produce a smaller voltage drop.

3. But because the voltage drop is smaller (2), the angle that the diodes conduct over will be smaller.

Therefore as the diodes have to provide the same energy as before (1), but over a smaller time (3) the peak current MUST be higher.

--
Nick
.

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