The square wave, expressed in digital form, will never be truly thus, there must alway be at least one sample period between successive samples, from -ve max to +ve max - which obviously then determines what the corresponding analogue slew rate will need to be, to be a correct reconstruction. As you say, in the analogue world the rise time will always be some value greater than zero, so 'perfection' can never be achieved there either.
The confusion has arisen because I used the word "perfect" to describe the trivial exercise it is for software to generate an audio track which at first glance looks to be, exactly a square wave. Which it is not, of course - just passing it through software equalisation with flat response immediately exposes the intrinsic ripple component, that is 'hidden' at the initial software creation of the waveform.
The confusion has arisen because I used the word "perfect" to describe the trivial exercise it is for software to generate an audio track which at first glance looks to be, exactly a square wave. Which it is not, of course - just passing it through software equalisation with flat response immediately exposes the intrinsic ripple component, that is 'hidden' at the initial software creation of the waveform.
Not a lot of difference IMO. I don't see 10-15% difference changing things enough considering a resonable overdesign margin.
Let us look at the costs! One square inch of .125" aluminum costs me about $.04. The cost to anodize it black is around $.02. So for heatsinks running under about 50 C the advantage is clear. For those running above that the advantage goes to a fan. But if a fan is not acceptable for either noise or MTBF then the advantage goes dark.
Simon,
If I am reading this correctly and not doing the math here it would appear that a small increase in surface area would be cheaper than the black coating for the small 10% differential you would get with the black. If space is at a premium then the black coating may be required but if not simply sizing the aluminum a bit large would make a greater differential. That does not mean we shouldn't use the black coating, just that surface area would seem to be the driving force here. Correct me if I am wrong, I could just do the math and answer my own question.
If I am reading this correctly and not doing the math here it would appear that a small increase in surface area would be cheaper than the black coating for the small 10% differential you would get with the black. If space is at a premium then the black coating may be required but if not simply sizing the aluminum a bit large would make a greater differential. That does not mean we shouldn't use the black coating, just that surface area would seem to be the driving force here. Correct me if I am wrong, I could just do the math and answer my own question.
Metal cost $.04 To get 10% better $.044
Anodized cost $.06
However anodized radiates better as temperature goes up. So as a heatsink gets to temperatures that one should avoid any human contact anodized becomes price effective. But a fan will keep such a heatsink cool enough to be safe.
So when a heatsink size is limited and you cannot use a fan then anodized is a solution. The other reason to anodize is that it looks good.
Shown is my Class A "Butterfly" amplifier.
Attachments
Soft anodizing usually uses a dye to get the color. Hard is a natural black-ish color depending on alloy. So for cosmetic use soft is better. There will be slight difference in radiation properties, but as the hard color depends on alloy predicting it is not practical.
I surrendered a long time ago, but you have not demonstrated the difference with big multi-fin heatsinks (they don't radiate through eachother) and reasonable natural convection (which also rises with temperature). But please we can can drop it.
BTW on your Bybee measurements, IMHO you still have no solid technical basis to make a statement like "they treat complex signals and regular ones differently".
I thought we were in agreement, it makes no economic sense to anodize heatsinks except in special cases.
I hesitate to show more Bybee measurements due to the amazing amount of heat that creates. But from unshown data that is my "Feel". You of course are entitled to your own opinion.
My intent on measuring the Bybees was to demonstrate that with careful (or some may consider ludicrous) measurements you should be able to distinguish between a Bybee and a resistor. Of course I also expect to be able to distinguish between resistors even of the same type.
I find that the Bybees do perform differently than a resistor of the same value and approximate inductance more than can be explained by RLC measurements.
Now I can make simple devices that also deviate from RLC measurements. That actually is a "Lab" that is given to freshmen. Again you are welcome to your own opinion.
ES
Putting aside actual measurement capability for inductance (several of the measurement gurus seemed skeptical), are they different than your R&R or between several different types of plain vanilla resistors of the same value? I asked that before and you told me that you only had one kind. Since 30m-ohm resistors are cheap, I'd certainly pony up to buy you 4 or 5 different kinds if you'll agree to do the same measurements the same way.
It's interesting that you have stated that the "Bybee effect" doesn't seem to work for sine waves, but your example measurements seemed to be sine waves. Could you enlighten me, please?
Yes, a 1N4007 would serve nicely. It doesn't even follow Ohm's Law!
I did get in a bunch of other resistors. They all behave pretty much so the same. The level of the loss from a sine wave is the same for resistors and the Bybee. The loss for "Noise" is greater.
Yes a diode is one of the non RLC components. What results do you think you would see from a wirewound resistor immersed in "iron filings?"
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