Using a notebook power supply for Raspberry pi

Thread Starter

saxa

Joined Jul 15, 2018
14
Hi all, sorry if I have not post this into the correct forum.

I havea raspberry pi which I use as a video surveilance with zoneminder software. It runs well from SD card. Now I want to expand the tihngs and add a SSD to be able also to record. When I connect the SSD to the USB port it runs but the RPi shows all the time the symbol its running underpowered.

I have some spare notebook power supply units which of course have the different ratings on the output, but surely enough power to deliver
the needed current for RPi and the SSD, the only thing is to know how to make the output voltage be of 5V and not 19V.

Any ideas on how could I modify the notebook power supply to get out the 5V with 3A or 4A ?

Rgds
Saxa
 

MrChips

Joined Oct 2, 2009
19,277
There is no easy way to convert 19V to 5V except with a buck converter (i.e. a switch mode power supply).
It would be best to find a 5V supply such as a USB charging port.

You don't have to worry about the 3A or 4A output. A 10A @ 5V supply will work just as well. Your RaspberryPi will demand whatever current it needs, usually less than 1A. Just make sure that the power supply can deliver more than what you need. For example, 2A or 3A will probably do for most situations.
 

Thread Starter

saxa

Joined Jul 15, 2018
14
Hi, I have right now the RPi power supply bought in the kit, which shows that should deliver 5V 2000mA but the RPi cries that its underpowered, the lightning symbol is appearing all the time when I connect the SSD to the USB port. This is the reason I was thinking to use something more powerful and I have few of them broken, which I could modify to deliver 5V instead of 19V but if there is no easy way then I will go with a new adapter capable of delivering 3A.
 

nsaspook

Joined Aug 27, 2009
6,279
I would use a powered USB hub to the SSD so the RPi doesn't need to supply current to the drive. The traces and poly fuse on the RPi board are current limiting factors.
 
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Thread Starter

saxa

Joined Jul 15, 2018
14
Thanks for the suggestion nsaspook, in fct I have a USB to SSD converter from an old USB portable HDD which has a separate input for the 5V, but I have not got with it the power supply at the time. Now the idea of using a more powerful PSU was eactly because I would like to possibly split the power connection and have to use only one unique power supply and not two.
But probably would be easier to buy a more powerful PSU and use that one to drive both things.
I thought that would be possible just to swap some components in the old notebook power supply so I could get a more powerful unit with 5V.
This is why I asked this question.
 
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