[Amps] Rectifier equilization?

[Manfred Mornhinweg]

Bill,

> FYI for next time, 6A10 diodes have become preferred by many for high power
> use because of their 6 amp continuous and 400 amp surge ratings and moderate
> cost. 

I don't mean to say anything against 6A10 diodes, they sure work fine. 
But they are HUGE overkill. Even if the filter capacitors had zero 
equivalent series resistance, and the power outlet where the amp is 
connected had zero impedance, and there were absolutely no inrush 
limiting system used, and the power were switched on in just the worst 
possible moment (peak of waveform), just the resistance of the HV 
transformer will limit the current to roughly 20 to 30A, or maybe 40A if 
the transformer is really beefy. And such a condition of course doesn't 
happen in real life - specially the line from which the amplifier is 
powered does have some resistance and also some inductance. In practical 
use, in a normal home, it would be really rare to see more than 15A 
inrush current.

1N5408 diode has a 200A surge rating, which is still big overkill. The 
humble 1N4007 with its 30A surge rating would be about the right part to 
choose for a cost-conscious builder! It's also comfortable with the 
average current. Rated at 1 ampere average, a bridge rectifier using 
strings of 1N4007 diodes is good for 2 amperes. That gives enough 
headroom for a legal limit amp.

Feel free, of course, to use big diodes, if it gives you peace of mind. 
But it shouldn't be technically necessary.


Jim,

> ##  Both my 1N5408 and 6A10  diodes have identical lead diameters.

So do mine.

> Both are I think,   .050 

Yes.

Manfred

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