?
Solved

powered USB ports?

Posted on 2001-06-25
6
Medium Priority
?
245 Views
Last Modified: 2013-11-09
are all usb ports that come pre-installed on desktops and laptops powered? I'm talking about the ones that are either part of the motherboard or PCI.
0
Comment
Question by:dolfanMT
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 13

Expert Comment

by:magarity
ID: 6225594
Usually, but not always.  Check the manual for the motherboard or laptop in question.
0
 
LVL 17

Accepted Solution

by:
rayt333 earned 200 total points
ID: 6226107
Like magarity stated usally they are powered but most only have a small amount to power an external device, if you are installing a device that requires a high load then you would be better off with a externally powered USB hub.

You will need to check the power requirements for the device and also see how much is available from the USB port.
0
 
LVL 32

Expert Comment

by:jhance
ID: 6226179
See:

http://www.allegromicro.com/techpub2/usb/power.htm

USB ports should provide up to 500mA of current at 4.5 volts.  Some laptops, however, do not provide any power at all since they don't really have much to spare.  Strictly speaking they are not USB spec compliant but that's life...

In general the specification for your laptop should define how much power, if any, is available to be drawn from the USB port.
0
Percona Live Europe 2017 | Sep 25 - 27, 2017

The Percona Live Open Source Database Conference Europe 2017 is the premier event for the diverse and active European open source database community, as well as businesses that develop and use open source database software.

 

Expert Comment

by:zouying
ID: 6231029
USB ports should provide up to 500mA of current at 4.5 volts

Actually, each of the ports is allocated 100ma. Besides the hub controller requires 100ma, you have 400ma left, which means, one hub has up to 4 ports, if bus-powered.

Well, in the drivers codes, all of these ports are powered up, actually, the port status is 0x0000100.

Maybe too much info to you.

Z/
0
 

Expert Comment

by:ComTech
ID: 6373352
Hello everyone,

This question has been open for quite awhile. I am going to allow feedback from the questioner and experts. If it is not resolved, I will delete or accept an answer based on the info I have been given. Experts, feel free to offer input. I will monitor this question for a period of 5-7 days and come back and evaluate.  

I reserve the right to disallow any comments that may not have a direct conclusion

Thank you,
ComTech
Community Support Moderator

*Question Author, please return and resolve this question.
0
 

Expert Comment

by:ComTech
ID: 6393929
According to PC ISO, all onboard USB ports are powered, albeit usually by not much.  rayt333 has the correct answer.

Thanks,
ComTech
Community Support
0

Featured Post

The Eight Noble Truths of Backup and Recovery

How can IT departments tackle the challenges of a Big Data world? This white paper provides a roadmap to success and helps companies ensure that all their data is safe and secure, no matter if it resides on-premise with physical or virtual machines or in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In the modern office, employees tend to move around the workplace a lot more freely. Conferences, collaborative groups, flexible seating and working from home require a new level of mobility. Technology has not only changed the behavior and the expe…
This article outlines why you need to choose a backup solution that protects your entire environment – including your VMware ESXi and Microsoft Hyper-V virtualization hosts – not just your virtual machines.
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…
Suggested Courses
Course of the Month10 days, 13 hours left to enroll

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question