Does the Model A have polyfuses


6 posts
by Jim JKla » Tue Feb 12, 2013 7:12 am
Does the Model A have polyfuses?
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick
User avatar
Posts: 1935
Joined: Sun Jan 29, 2012 11:15 pm
Location: Newcastle upon Tyne UK
by jojopi » Tue Feb 12, 2013 10:04 am
Jim JKla wrote:Does the Model A have polyfuses?
It has a polyfuse, F3, 750mA hold. See underside at: http://www.pcper.com/news/General-Tech/ ... -256MB-RAM

Why do you ask? Even if you subscribe to the conspiracy theory that polyfuses are flawed, they are easy to bridge.
User avatar
Posts: 1867
Joined: Tue Oct 11, 2011 8:38 pm
by Jim JKla » Tue Feb 12, 2013 11:00 am
I ask because I want to keep my hardware unaltered (Yes I am a Purist) I am purchasing a Model "A" and want to know if I am going to set aside a cable to power the primary micro USB or if I will be able to back power from the USB and would therefore be setting aside an ordinary USB.

I am buying an "A" to field test setups and provide notes that will be used by Noob users, and bearing in mind they will probably be using their "A" out of the box with no prior knowledge of polyfuses and their implications.

I am not part of, or hold any truck with any conspiracy theory as regards polyfuses and their usage. ;)

All I realy needed here was a one word answer of "Yes" or "No" :D
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick
User avatar
Posts: 1935
Joined: Sun Jan 29, 2012 11:15 pm
Location: Newcastle upon Tyne UK
by jojopi » Tue Feb 12, 2013 11:46 am
Jim JKla wrote:All I realy needed here was a one word answer of "Yes" or "No" :D
Not really. You asked if there are polyfuses, plural. It is impossible to answer that correctly using yes or no.
User avatar
Posts: 1867
Joined: Tue Oct 11, 2011 8:38 pm
by Burngate » Tue Feb 12, 2013 12:49 pm
jojopi wrote:
Jim JKla wrote:All I realy needed here was a one word answer of "Yes" or "No" :D
Not really. You asked if there are polyfuses, plural. It is impossible to answer that correctly using yes or no.

Actually, since the original question used the word "polyfuses" and the model A has a "polyfuse" the correct answer has to be "no", "polyfuse" being different from "polyfuses"

And since his question had the hidden implication that polyfuses in the USB connector to main 5v rail were the only ones of interest (as more explicitly implied in the third post) then not only would "no" be gramatically and pedantically correct, it would also answer his question :roll:
User avatar
Posts: 2337
Joined: Thu Sep 29, 2011 4:34 pm
Location: Berkshire UK
by Jim JKla » Tue Feb 12, 2013 5:50 pm
OK Does the model A have polyfuses on the USB connection that would prevent back powering the RPi through the one USB A type port.

Yes or No? ;)
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick
User avatar
Posts: 1935
Joined: Sun Jan 29, 2012 11:15 pm
Location: Newcastle upon Tyne UK