I am currently working on a project where i have micro-controller,stepper drivers etc all powered through a single 12v 10a power supply. I was planning to use the same supply to power the raspberry pi Zero W using a 7805 voltage regulator..

  • Is it safe to do so..?
  • If not are there any other way/method using which I can power the pi using same supply..?
  • It MAY work (assuming you use a big enough heatsink and don't attempt to power any peripherals). The rest of use would use a switch mode supply. – Milliways Jan 17 at 10:53

A generic 7805 in T0-220 package can supply between 1A and 1.5A (and peak at 2A) but all that depends on adequate heatsinking and sufficient input voltage, this gives you 5W of power. The Pi Zwero W can draw around 1.2W so, on paper, should be well within the capability of a 7805.

However most of the power packs I've seen actually put out 5.1 to 5.2v so I'm not so sure a 7805 would quite work, perhaps consider an adjustable linear regulator like the LM317 instead that you can set to 5.1v.

The other issue you might have is the efficiency, you've included the "battery" tag on your question but only mention that your have a 12v 10A source. As a (simplified) example a 7805 driving 5v at 250mA (or 1.25W) from a 12v source needs to drop 7v, this is turned into 1.75W of wasted heat that you need to dissipate. If this matters to you then a buck converter is going to be more efficient, some of the smaller pre-made modules can be quite affordable and have adjustable outputs and current limits but you'll need to keep an eye on the output noise under load and maybe add decoupling capacitors if it's a problem. Or you can build your own if you're so inclined.

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