AC/DC Power Supply

Hi all,

I need some help figuring out what power supply AD/DC module to use for my projects. I’m not a electrical engineer so this is a bit over my head. I just don’t know if I should use a 2w or 3w power supply?

Thinking of using a Vigortronix converter, VTX-214-003-205 which is a 3W, 5v converter and can supply 600mA output current or the VTX-214-002-105 which is a 2W, 5v converter with 400mA output current. Or something else? Most of my projects will be able to tap into the main power so I want to use that and not have to power via a wall wart.

I’ll have a few sensors attached but it will very from project to project as to exactly what I’ll be using. So I want something that will have enough for the photon and extra for a few other things.


So, the Photon itself only uses 80mA during typical use ( ), and significantly less with a little energy optimization like utilizing sleeping, etc.

Most basic sensors will have extremely low power requirements, as well. Unless you have a ton of lights to power, or something like that, either the 5v 400mA or 600mA supply should treat you very well for starter projects! As you start doing more and more, you may find you want more power, so you might want to buy slightly big now to avoid having to upgrade later.

As you know, it depends on power used in the project.

I like to use my bench power supply (which shows current draw) and cover the power with a reasonable amount of overhead.

do you have access to a bench-top power supply or ammeter?

No I don’t have anything that fancy :disappointed: I have a MultiMeter and a quick check shows it can measure current up to 400mA. I’ll give that a try tomorrow.

Up till now just been toying with the photons and using usb power. A few breakout boards for sensors and a display but now I want to create something that doesn’t need external power or has everything exposed.


If you are using USB power for testing, I’d not go below 500mA as this is the current standard USB ports will supply (USB 3.0 will got to 600mA).
In order to avoid having to say: “It worked via USB, but now it’s not”, I’d go for 600mA to be on the safe side.

DMMs will not be quick enough to give you reliable readings when it comes to current peaks.
Also consider, the standard current draw of the Photon is said to be 80mA (not counting spikes during WiFi connection), but with all GPIOs pushing current you may be looking at an extra of 8mA to 20mA per pin.
So it very much comes down to your use case.

Thanks for all the help everyone. @ScruffR I think I’ll just go with the 600mA. I defiantly don’t want to b be saying: “It worked via USB, but now it’s not” lol