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I have an Eleksmaker laser cutter which has a board with a 12V output (see top of image).

enter image description here

I would like to power my RaspberryPi using this 12V output.

What is the advantage of powering the RaspberryPi over microUSB instead of hooking 5V onto the GPIO pins?

Though I can easily cut a microUSB cable in two and attach the wires, how can I reduce the voltage from 12V to 5V?

What other things should I be concerned with, or would I need to verify, before trying this out reasonably safely?

  • en.wikipedia.org/wiki/Voltage_divider You can do that with resistors, but I think it is relatively inefficient; a better idea efficiency wise would be a buck (opposite of "boost") converter. – goldilocks Jul 7 '19 at 19:06
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    @goldilocks you can not use a resistive voltage divider; theoretically you could, but the equivalent series impedance would need to be <0.2Ω - even if you could get suitable resistors the divider would dissipate ~250W and make a nice radiator. – Milliways Jul 8 '19 at 0:17
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I use buck converters that convert 12VDC to 5VDC
to power most of my
raspberry pi computers.
There are many available but be sure to
check the amperage output.
Most come with a USB A 5VDC output and that way
you can use the microUSB for power thus having fuse protection
My RPi Zero computers for my weather station
as well as my RPi3B+ camera are all powered this way.

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I often power a Pi via the 5V and ground pins on the expansion header.

Typically I feed a laptop wall-wart PSU into a 5V UBEC. I connect the 5V UBEC output to the expansion header.

Search this site for the advantages and disadvantages.

Typically the microUSB socket gives you the polyfuse protection and it's less likely that the power polarity will be wrong.

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