Powering Orange PI Zero with a Power Bank

You might ask yourself why wouldn't it work?
I asked myself the same question when I saw the tiny thing won't turn on, or worse, turn on and freeze all the time.

The answer lies in the way power banks work and some of the power converters, as well as usb power supplies.

In the good old days when you wanted to take a power source like 220v or 110v and down convert it to 5v, you would use a transformer, then a rectifier and lastly filter out the noise with a capacitor and optionally an inductor. This works great and if used on audio applications the noise is inaudible or very close to it (at least not from the power source) but the biggest drawback of this method is weight, high power transformers weight a lot.

These days there is a need to make things smaller and weight less and so we have all sorts of switching power supplies and as their name implies, they switch the power on and off to achieve the same goal.

In general there are 3 types of switching power supplies:
- step-up, also referred to as boost converters where the input voltage is lower than the output.
- step-down, also referred to as buck converters where the input voltage is higher than the output.
- buck-boost converters where the input voltage can either be lower or higher.

In my particular case it is step-up converter from a Lithium Ion battery so 3.7v - 4.2v up to 5v

But lets look how bad it is

If you look at the ripple size, it pretty much covers the whole voltage output range, a very fast ripple but still.

Looking at the Orange PI Zero, there seem to be another relatively large inductor next to the USB connector where power comes in:

Which led me to believe another type of switching is going on the PI and common sense dictactates that two switching power supplies without some type of smoothing or filtering is a bad idea.

So I decided to experiment with a small 220uf capacitor and solder it straight on the power bank

And voilà !

124mv !


But the best part is, its actually working and stable.

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Tags: Orange PI Zero., Power Bank, power supply

Dror Gluska June 17, 2017  1 comment

50V 15A Power Supply - $140

I've recently found myself in need of a more powerful power supply than my loyal 50V 3A  Circuit Specialists (CSI5003X) I had for many years.

So when I did a bit of research, I've found out that even now prices are not very low for a more powerful power supply I've decided to try and DIY it without doing any electronic work.


A while back I've seen the DPS5015, which is a 50v 15A programmable power supply which has other versions, 30v/50v, 2A/3A/5A/12A and 15A, add on top of it the possibility to DIY your own programming and it looks like a winner to me (~$37). 

You can even get an enclosure with a fan for it (~$24).

But that is just the controller, it needs a power source of some sort, I've looked around and found a 48v 16.7A switching power supply (~$73).

Throw in a couple of banana screw terminals ($1-2) - don't get the cheap ones, they fall apart.

and add a 3 Terminal Power Socket with Fuse Holder and you have a working power supply (don't forget the fuse! I've used 5A)

A few wires and a cover for the power supply and you're done.

For now, the only drawback I've seen is that this specific PSU doesn't monitor the temperature and power the fan accordingly, so the fan is always on, making a lot of noise.

I've thought about adding something like this to fix that, but I'm not sure yet, need to do a bit more reading about it and see if the power supply needs an always on cooling or not.

In the end, the time and effort to find the parts, read, design a back cover, print it and build it took a long time and I'm not really sure its efficient use of one's time, but I've had fun doing it! 

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Tags: power supply

Dror Gluska May 14, 2017  No comment