> a) what heuristic are you using to determine that power consumption will be 25% of the power supply sizing, and
I'm not the OP, but it's probably about right. Power supplies are cheap and there are variances in manufacturing. Typically power supplies for all consumer electronics are rated for double peak load. And assuming that standard load is half of peak load is probably on the high end - standard load for the processor(s) is probably more like 1/10 peak load, but there could be other components on the board whose electrical load is not workload dependent.
Basically none, because that isn't how capacitors work. Capacitors voltage drop linearly with respect to the amount of stored energy. They are useful for transients in the very high frequency regime, not multi millisecond long periods.
That depends how much smoothing you want and how much you're prepared to pay for it.
Every AC-DC converter necessarily has some energy storage in it to cover the part of the cycle where the voltage crosses through zero. There's capacitors on the input and output of buck converters. But smoothing over more than one AC cycle? Not really much point in doing that.
Thanks for that. I rarely take much notice of PSU's, other than desktop computer builds, where the received wisdom seems to be aim at using around, or just under, 1/2 of the spec'd capability of the PSU.
Seemingly this is optimal for efficiency of the device, and I've never really thought about how or why this claim is made -- opinions are consistent, pricing is rarely significant, etc.
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In particular, a WiFi radio uses a comparatively large amount of power but in short bursts. Gigabit ethernet likewise.
https://www.computerweekly.com/blog/Networks-Generation/Powe...
How much of that can be stored in capacitors to smooth out the peak AC load? Is that done at all?
Basically none, because that isn't how capacitors work. Capacitors voltage drop linearly with respect to the amount of stored energy. They are useful for transients in the very high frequency regime, not multi millisecond long periods.
That depends how much smoothing you want and how much you're prepared to pay for it.
Every AC-DC converter necessarily has some energy storage in it to cover the part of the cycle where the voltage crosses through zero. There's capacitors on the input and output of buck converters. But smoothing over more than one AC cycle? Not really much point in doing that.
Thanks for that. I rarely take much notice of PSU's, other than desktop computer builds, where the received wisdom seems to be aim at using around, or just under, 1/2 of the spec'd capability of the PSU.
Seemingly this is optimal for efficiency of the device, and I've never really thought about how or why this claim is made -- opinions are consistent, pricing is rarely significant, etc.