Power ratings at startup spike

[Eddododo]

Looking at a typical power/filtering circuit; at power-up, current flows briefly through the filter caps etc. Looking at a sim of a couple circuits, it looks like at much as 1.5W for the briefest moment, something like 5ms.

When choosing the power rating of resistors and making considerations about lifespan, does one need to consider these spikes, or are they negligible? Assume I mean a known-good circuit, say a Rat or something... A Rat's power section shows almost 2w instantaneously, for example.

[Rob Strand]

Looking at a typical power/filtering circuit; at power-up, current flows briefly through the filter caps etc. Looking at a sim of a couple circuits, it looks like at much as 1.5W for the briefest moment, something like 5ms.

When choosing the power rating of resistors and making considerations about lifespan, does one need to consider these spikes, or are they negligible? Assume I mean a known-good circuit, say a Rat or something... A Rat's power section shows almost 2w instantaneously, for example.

It's a real effect that does need considering in the design.

Most of the topic is discussed in this thread,
https://www.diystompboxes.com/smfforum/index.php?topic=131795.msg1281686#msg1281686

Unfortunately pulse power rating curves are not often published.

[antonis]

calculator

In brief, don't bother..
(those effects exhibit negligible inrush current..)

edit: I presume you're talking about the low value series resistor of power supply input LPF..