This is my first attempt at working with electronics so sorry for the potentially stupid question!
For my A-Level Product Design project I am making a digital photo frame with built in bluetooth speakers. I am using a Raspberry Pi as the controller for the photo frame and plan to use a bluetooth amp for the speakers.
I need my product to use a mains power supply, however I don't know how to split a single mains cable to 2 separate devices on the inside of my product.
From research I have found that the Raspberry Pi needs 2.5A "Recommended PSU current capacity" and 5.1V Power supply (I wish I knew what this meant). Since I have no idea what i'm doing, I am yet to order the bluetooth amp until I know for sure which will work.
My question is; How do I split a mains power between two devices, and do I need to order a bluetooth amp with the same statistics as the Raspberry Pi?
Any help is much appreciated,
Ollie
Best Answer
It's best to avoid working in mains power at all: Safety; ease of getting UL/CSA listing; and ease of changing power supplies if you change countries.
You may have noticed that almost every small machine uses a wall wart power supply. This is why. They can focus on their low-voltage gadget and not worry about also designing a mains voltage power supply and getting that listed. The wall-warts are commodity items, and are already UL listed.
Lately the trend is USB power, but that only works if your load is less than 5-12 watts. Yours is more.
So first... Choose a speaker module that runs on the same voltage (5.1) as the Raspberry Pi. This won't be hard; 5V is a popular voltage.
Then total the current requirements for both Pi and speaker.
Then look for a wall-wart that outputs the correct voltage and at least the total current, preferably a bit more. Too much current is good, too much voltage is a problem.
Then search for a connector socket which fits the plug on the wall-wart, and fit that into the back of your chassis. Split power from there to both devices.