Hi need help on two questions - power from TV

[Richard24red]

Hi everyone I have two questions that are driving me and I'm new to the whole pi concept. Right my two questions are one I have my pi powered by my TV (its a smart TV kdl32705cbu sony bravia model ) and I was wondering and abit worried will it hurt the tv in anyway. My second question is I'm planning on buying a USB hub for my pi to connect a hdd portal none mains powered will that hub back power the pi and destroy it or is that just when you have a pi plugged into a hub not a hub plugged into a pi hope I made that last question clear

Thanks you for your time

[Laurens-wuyts]

I was wondering and a bit worried will it hurt the tv in anyway.

It shouldn't be a problem for your TV. (except when you are using high power USB devices without a hub)

Will that hub back power the pi and destroy it

There is a chance that the hub will back power the pi, the problem with back power is that you skip the fuse (so no protection), so I think it's better to find a hub which doesn't back power.

Laurens

[DougieLawson]

You need to keep your power budget below 500mA because that's the max current draw you're supposed to take from a USB 2.0 connection. It won't hurt to pull more, but the computer (running embedded Linux) inside your TV may legitimately decide to disconnect the high current USB device.

[RaTTuS]

unless you are using a model A then you get 4 portss and don't need a HUB
personally I'd power the RPI with a decent 2A PSU and have done with any power issues [as long as you have dcecent micro USB leads

[Navyscourge]

If you have peripherals that need a significant power level you will need a powered hub. I am using this one: http://thepihut.com/products/7-port-usb ... spberry-pi which powers the Pi and several peripherals, including a HDD

[fruitoftheloom]

Hi everyone I have two questions that are driving me and I'm new to the whole pi concept. Right my two questions are one I have my pi powered by my TV (its a smart TV kdl32705cbu sony bravia model ) and I was wondering and abit worried will it hurt the tv in anyway. My second question is I'm planning on buying a USB hub for my pi to connect a hdd portal none mains powered will that hub back power the pi and destroy it or is that just when you have a pi plugged into a hub not a hub plugged into a pi hope I made that last question clear

Thanks you for your time

What Model of Raspberry Pi do you have ?

https://www.raspberrypi.org/help/faqs/#power

[Richard24red]

Thanks you for all your replys I understand about the tv its not gonna harm it thanks you

Now about the hub and pi model I have the raspberry pi 2 b and I need a hub to play the external hdd wich is a portable so its not powered by anything I've tried just plugging into the pi with a USB powersupply but it won't power it just comes on for a second then off and it keeps repeating it so basically just need a hub to keep it on

Thank you

[fruitoftheloom]

Thanks you for all your replys I understand about the tv its not gonna harm it thanks you

Now about the hub and pi model I have the raspberry pi 2 b and I need a hub to play the external hdd wich is a portable so its not powered by anything I've tried just plugging into the pi with a USB powersupply but it won't power it just comes on for a second then off and it keeps repeating it so basically just need a hub to keep it on

Thank you

The RPi B+ & 2B if using a quality 5v2A PSU can power a 2.5" USB Drive, see:

https://projects.drogon.net/testing-set ... berry-pi-b

Code: Select all

max_usb_current=1

This will increase the USB BUS from 600 to 1200ma

Power the RPi from a TV may lead to undervoltage and issues.......

[Richard24red]

Sorry Im a bit new to the pi so your saying that if i have a usb hub to only power the hard drive that could damage my pi ?

[Laurens-wuyts]

When you are using an external power supply for the Raspberry pi (5V 2A) you are able to use the HDD without a USB hub.
You can use a hub, but that is not necessary.
But then you'll need to change the setting for the power to the sub ports (see up).

Laurens

[fruitoftheloom]

Sorry Im a bit new to the pi so your saying that if i have a usb hub to only power the hard drive that could damage my pi ?

The RPi has protection circuit so powering from a Hub or TV is not an issue.

The issue is USB2 only provides 500ma, whilst USB3 900ma...

Therefore considering the RPi2B requires a minimum of around 350ma just to boot, if you plug in any peripherals you will have an unstable RPi.

If you follow advice above and use a decent PSU, you will not need a USB Hub...

https://www.raspberrypi.org/help/faqs/#power


PersonallyI have a RPi 2B with the RPF PSU & Wifi Dongle as well as cheap USB Keyboard & Mouse and a USB3 Hard Drive. I have no issues with the hard drive spinning up or being stable undertaking file transfers

https://www.raspberrypi.org/products/un ... wer-supply

https://www.raspberrypi.org/products/usb-wifi-dongle

http://www.argos.co.uk/static/Product/p ... 339361.htm