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poe "soft start"

Posted: Sun Aug 27, 2017 1:58 pm
by gryeden
Might it be considered that a "soft start" function be implemented on the poe power outputs ,whereas the power applied to the poe output would be administered over a few milliseconds as opposed to an "instant on". There would be benefits to such a feature.

Re: poe "soft start"

Posted: Mon Aug 28, 2017 11:54 am
by sirhc
gryeden wrote:Might it be considered that a "soft start" function be implemented on the poe power outputs ,whereas the power applied to the poe output would be administered over a few milliseconds as opposed to an "instant on". There would be benefits to such a feature.


Not sure I follow you?

Re: poe "soft start"

Posted: Mon Aug 28, 2017 12:10 pm
by lligetfa
Since there is possible inrush current, I would think you would actually want the opposite of a soft start so as to get the voltage up as quickly as possible to reduce the current. The polyfuses are thermal in nature so getting past the inrush sooner means they are less likely to get hot. So too, the Ethernet transformers.

Re: poe "soft start"

Posted: Mon Aug 28, 2017 12:25 pm
by sirhc
There is a STAGGER or delay between powering up all the ports.

So if your turning on 4 ports it turns 1 on at a time waiting 0.5 seconds before turning up the next port.

Re: poe "soft start"

Posted: Sun Jun 16, 2019 9:42 am
by gryeden
While I was working in GM development lab , it was found that "cold" loads actually exceed current draw momentarily when power was applied. We solved the issue with a soft start feature. Ever notice that when you flip a light switch , that is when the bulb is most likely to burn out. Because the filament is cold , the surge current exceeds the bulbs ability to dissipate the heat , and poof.