electrical engineering isn't my strong suit, but Im trying to do a home project with some automation to it. I just don't know how I'm supposed to provide power to some higher voltage components that I wouldn't be able to power off, say, GPIO pins from a Raspberry PI or something.

I can get a bench power supply off the internet and use that to form my circuits, but I don't know if that's the way it should be done. What's the way people usually power projects.

The component that I need to control now is simply a small fan, but my solution needs to be extensible to more components in the future, and I need it to be DC powered so I can control it using a circuit.

Thanks for any help!

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    \$\begingroup\$ a bench supply is useful while developing your project, but once it's completed, use a supply similar to those used for commercial appliances (Hacktastical's answer) \$\endgroup\$ – Jasen Aug 2 at 4:19
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    \$\begingroup\$ Do share your ideas on the project :) ( new topic) \$\endgroup\$ – Sorenp Aug 2 at 5:29
  • \$\begingroup\$ I want to fully automate the process of growing vegetables. In the way future, I want to but a Neural Network in full control of all the components and teach it to efficiently grow stuff, which is why I can't just have a whole bunch of AC components. @Sorenp \$\endgroup\$ – Chris Aug 2 at 12:28
  • \$\begingroup\$ To control higher power and/ or voltage from an MCU gpio you can use (1) a relay, (2) a mosfet, (3) a bjt. Depends on what you're controlling and how you're controlling it. You have not clearly specified. The PS itself has a huge selection range. \$\endgroup\$ – Kripacharya Aug 2 at 16:00

The cheapest, most universal way is to use a USB connector for 5V. I’ve taken to using this method instead of buying barrel-plug power supplies. It has saved me a lot of time and effort. You can find adapters to USB power from just about anything you might find in the home: batteries, solar chargers, 24VAC (think sprinklers, doorbells, theromostats), line voltage, your R-Pi, your desktop PC, etc.

For higher voltages (9, 12V) at moderate current (2-3A) look to the barrel plug type. CUI makes both the barrel receptacle and wall-wart supply in various output voltages. Phihong is another popular brand for this kind of power supply. You can find these on Digi-Key, Mouser, etc.

For even higher voltages (24, 48V) and currents (3A or more), consider a screw terminal block. A popular quality brand of high-power supply for these is MeanWell. Jameco and others sell these.

Some really high power projects can use a PC power supply and use the ‘GPU’ 12V power connector, or native ATX. It’s hard to beat an ATX power supply in terms of availability and watt/$. You can also find line-to-GPU power as a separate unit - mining rigs use this type sometimes.

  • \$\begingroup\$ That is all true for the finished project. I just want to point out here, that during the actual project phase, a bench supply might be a good idea. It gives you a fault tolerable power supply with current limiting - so you want make as much damage, when there is a fault in the circuit =) \$\endgroup\$ – jusaca Aug 2 at 5:20
  • \$\begingroup\$ You get that from a USB supply, too. So even for prototyping it’s a good choice. \$\endgroup\$ – hacktastical Aug 2 at 5:38
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    \$\begingroup\$ USB power supplies are notoriously hit and miss. There are many very bad, poor specification units out there, especially from some of the Asian suppliers. I avoid them and use laptop power supplies (usually 19V), readily available, and the certifications normally mean something when from respectable suppliers. I then use DC-DC convertors to get to 3.3, 5 or up to 12V. You can buy cheap laptop replacements, but those from Sony, Samsung, DELL, ASUS and the like are typically rock solid. I also use lots of things like Xbox power supplies which are terrific supplies with remote sensing included. \$\endgroup\$ – Jack Creasey Aug 2 at 6:16
  • \$\begingroup\$ Thanks! I think I'll start with USB for now just to throw something together while I'm in the process of moving and then move to your obviously more extensible solutions. For using PC power supplies though, they often have terminals that don't interface directly with my alligator clips or whatever I'd be using, since they're made to plug into computer parts. The same applies for laptop power supplies and the like. How would I go about drawing power from them in a safe way? \$\endgroup\$ – Chris Aug 2 at 12:34
  • \$\begingroup\$ You would not want to use alligator clips for a PC power supply. The hard-drive ‘Molex’ connector is still available, suitable for a system using up to 5A. \$\endgroup\$ – hacktastical Aug 2 at 19:54

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