diff --git a/hp_psu/notes.typ b/hp_psu/notes.typ new file mode 100644 index 0000000..e1ceccf --- /dev/null +++ b/hp_psu/notes.typ @@ -0,0 +1,27 @@ +#import "@preview/acrostiche:0.3.1": * + + +#init-acronyms(( + "PSU": ("Power Supply Unit","Power Supplu Units"), + "PCB": ("Printed Circuit Board",), +)) + += Exploration of the retrofitting of HP Power Supplies to EET + +The objective is the build a proof-of-concept for using an EET capture card on the 12V rail of a server #acr("PSU") without changing the form factor. +The targets are as many HP server-grade #acr("PSU") as possible. +At the time of writing this note, we have access to three #acrpl("PSU"): + - // fill with infos + + += Current Share ISHARE pin +Because the server #acrpl("PSU") are tightly integrated, it is very difficult to tap into their 12V rail. +The difficulty comes from the fact that the current gets generated directly on the #acr("PCB") and is not carried over a wire that we can cut. +Cutting a trace of tampering with the #acr("PCB") is completely out of the question. + +Fortunately, server #acr("PSU") have a feature called ~Current Sharing~ that enables using multiple sources to provide more current to a system. +The simplest implementation would be to connect multiple #acr("PSU") in parallel to the same 12V rail. +This solution is presented to be non-robust by many sources although they all recomend to use an external system that share the load between the sources, which is exactly what this solution is doing. +In any case, the server #acr("PSU") often include an analog output that is proportional to their current and enables an external circuit to adjust their voltage based on their current to spread the load. +This analog output can also serve as an information source for remote monitoring system. +The actual reason why this output is there remain somewhat hidden but the important fact is that the #acrpl("PSU") provides us with their current information, which is all we nned. diff --git a/resume/profile.png b/resume/profile.png deleted file mode 100644 index f883db0..0000000 Binary files a/resume/profile.png and /dev/null differ