Unresolved Current regulation.

Hi guys.

I plan on creating a rundown of all the modifications I've made to my printer so far in order to help newer people get the smoothest setup they can and maybe give others some things to think about. Before I can do that there are a couple of little issues I need to work out in order to get my printer running how I would like it to. Hopefully someone can give me advice on that that'll in turn allow me to create my setup post for others

The issue I'm having is not strictly printer related. More general electronics related. What I've done is I have got OctoPrint running on a Pi. I don't want the second plug coming out of my printer to run the Pi so I tried using a voltage regulator to limit the current from the board inside the printer to something the Pi can use (5V down from 12V). The Pi runs fine.

The problem is that the wifi adapter used to connect the Pi to the internet won't turn on if powered from the printer, but will if powered from a plug. I measured the current coming from the printer and it sits at a whopping 4.5 - 5 amp. The voltage regulator I bought says the output is 3 amp max, but I don't know if that means it can output 3 amp max or if it can only handle 3 amp max. Here is what I bought: http://irishelectronics.ie/epages/9...jectPath=/Shops/950018241/Products/"USB STEP"

The images below show how I've wired it in.

Could anyone give me an idea as to why the wifi adapter works when the Pi is powered using the plug but not the printer? I'm guessing it's the current... Any ideas on how to fix that? Buy a more expensive regulator?

Here is the wifi adapter: http://www.tp-link.com/en/products/details/cat-11_TL-WN823N.html

Thanks guys!

 

I thought that too, but 4.5 to 5 amp? Something like a laptop only uses maybe 3. I just assumed it was more of a safety feature of the wifi adapter. That maybe it was receiving too much current and it decided not to turn on to protect itself. I'll check and see if I have a meter to find out exactly what's needed. Good call!

So the output is 3A max but I'm reading almost 5 amp. Would that suggest the regulator is defective?

 

Gotcha. So find out what it needs and then work from there. I took a chance on that regulator because it was so cheap. Would have been nice to have it work with no issues straight away!

 

Thanks! Just one more question: Is this what you mean by 'meter'? http://www.ebay.ie/itm/USB-Charger-...hash=item35f96671c3:m:mQZk1eztr96TOcrEy468B0w

Also, here: https://www.raspberrypi.org/help/faqs/ I noticed it says

"We have found that purchasing a 1.2A (1200mA) power supply from a reputable retailer will provide you with ample power to run your Raspberry Pi for most applications, though you may want to get a 2.5A (2500mA) power supply if you want to use all 4 USB ports on the Models B+/2B/3B without using an external powered USB hub."