I have khadas VIM2, and decided to use it as a home file storage based on Ubuntu Server with an external hard drive. The hard drive will consume additional power, so I need to provide khadas extra power. For this, I bought a switching power supply Mean Well NES-15-5, its characteristics can be found here.
And also, the Amlogic s912 heats up very much when it work, so I decided to make a big aluminum radiator and bought a fan, which runs from 5v and consumes up to 140mA.
When I prepared everything and connected it, I found a couple of problems:
The cooler was connected with 2 Pins 0.8mm Pitch JST Header to the Cooling Fan connector, but after turning on the device, the fan does not rotate (when connected to a separate 4.5V supply, it works). I measured the voltage on the Fan port, it varies between 0.6 and 1.6 V. What did I do wrong and why fan doesn’t rotate?
The External Power Supply I connected with 4 Pins 1.25mm Pitch JST Header, and adjusted the voltage at 5V. The external hard drive is connected to the USB port closest to the USB-C port. After the power on, the VIM2 indicator lights up, it starts boot up, the HDD box indicator lights up, but the hard disk’s spindle does not twist and clicks are audible. I think that the drive does not get enough power, but if VIM2 gets power using USB-C from 5V/2A AC adapter - in this case the HDD works fine. Why is this happening? The HDD box is connected using a cable male-USB 3.0 micro-B - USB Type A.
I don’t recall maximum fan header load, but 140mA might be close. Update: Checked schematic, 150mA max load.
I saw these little Mean Well power supplies and was curious. Assuming it has sufficient current to power VIM2 + External HD. Be curious to know how clean the PS’s output is.
Hi again, first item resolved, thank you with @balbes150 very much! I will still experiment with the settings of the script, but after connection the fan works.
About the power supply, it will be great if the characteristics correspond to the real values. Anyway, if to look at the PCB, it becomes clear that the quality of used parts is higher than have chargers of mobile phones for $ 3.
Ive been using these mean well power supplies for a while, the little ones and a 40A 5V one for powering 10 single board computers - they are really great - had 8 of them running at load 24x7 for ~15months now and no problems and clean output. Recommended!
I think balbes150 plans script for temp controlled fan speed at some point.
Sorry, don’t have any suggestions for power issue at the moment. It would seem the Mean Well PS should be sufficient to your needs.
USB-C port handles up to 2600mA(fuse protected), that would also seem sufficient. USB 2.0 ports are fuse limited at 500mA and 900mA. Check schematic, as I don’t recall which port offers the 900mA, but will check tonight.
Don’t worry @RDFTKV, I know which of USB2.0 port limited at 900mA, my HDD was connected exactly in that USB port, but it’s doesn’t work, if the power is delivered by Mean Well PS. So, I think the limitation is related to the port, connector or wire cross section. Although I can be wrong.
The result of this story was the power supply does not produce more than 800mA at 5.0V. I already sent a request to the distributor and I am looking for another power supply.
