
Vampiric Charger: Any Source to 5VDC - crankylinuxuser
https://hackaday.com/2018/07/29/vampire-charger-is-a-rugged-anything-to-5vdc-converter/
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zaarn
That's quite an interesting project.

I've recently discovered the OKI 78SR. It handles about 1.5A of power at 5V
and accepts a very wide input range from 7 to 36 V and is easy to hook up.
Since I have a lot of 24V supplies it's very ideal for my use cases.

Sadly, I can't see if there are any images but for any sort of "universal"
power input I would consider several factors to be important;

\- Isolation; The power charger should isolate input and output as much as
possible, IIRC a common rule of thumb is to ensure that the device can handle
a 1kV voltage without the output going above specification voltage

\- Noise; Switch mode regulators like the 78SR produce a lot of line noise. I
imagine a device like this won't be silent either. In some cases it means no
reception of wifi or mobile during charging, worst case you get the FCC or
legal equivalent in your country knocking at the door (happened once to me,
never buy cheap long-range wifi routers from china)

\- Protection circuits; A charger should protect against shorts and overloads
or overcharging (I had a wall charger once that was able to detect phones or
battery banks overcharging their cells and switch them off while being able to
also run basically all normal devices like Portable Harddrives). Protection
should also extend to grounding everything properly to protect the users.

\- Cost; all of the above must be cheap and durable. Nobody wants chargers
that die after 6 months or costs 60$. Worse if it's both.

Building and designing chargers or power supplies is hard because you have to
deal with any of the above (or in some circumstances with none of them
depending on target market).

