The best Raspberry Pi power supply


Ok, since we already documented a little about the importance of a good PSU (Power Supply Unit) when audio quality is your main concern. As stated earlier, the raspberry pi power supply is also responsible for proper functioning of our tiny device, as a poor quality psu will result almost certainly in a corruption of your SD Card.

So that’s why I’m stressing this a lot. Most of the times, malfunctions of the pi are to be tied with a bad PSU. A proper Raspberry Pi Power Supply must be rated (and comply to ratings…) at 5v ( and real world output should be between 4,75 Vdc and 5,25 Vdc) and at least 1 A (if you plan to connect other devices to your Pi).

These are the PSUs I took for comparison. From left to right: a Sony Xperia mobile charger, 2 cheap chinese Psus and a 1A usb Hub PSU.

The best Raspberry Pi power supplyWithout digging into technical details, I can tell you that best results came with the Xperia Mobile Phone charger. Using the third PSU repeatedly corrupted my SD, while the other 2 were ok but sometimes I heard some pop noises from the loudspeakers. So, choosing the best Raspberry Pi Power supply could seem like a random choice, if you’re luck you’ll get one suitable, if don’t you just buy another one and so on. But we don’t want to just pick a random choice, don’t we?
OK, time to get a better Raspberry Pi PSU, the right way.

If you feel like If you want something done right, do it yourself, there are only  2 options for you, mate. Diy or full Diy.

Or this, which I would like to but I fear it might result in an extremely poor WAF, (even if I’m not married…)  :

Full DIY Approach

What we do need here is something that is worth the pain of looking for the components, buying them, solder them on a breadboard and put it in a box. If you are the kind of guy who likes all of this stuff, well, this is for you.

The core of a good PSU is it’s regulator. So, for newbies:

In electronics, a linear regulator is a system used to maintain a steady voltage. The resistance of the regulator varies in accordance with the load resulting in a constant output voltage. The regulating device is made to act like a variable resistor, continuously adjusting a voltage divider network to maintain a constant output voltage, and continually dissipating the difference between the input and regulated voltages as waste heat. By contrast, a switching regulator uses an active device that switches on and off to maintain an average value of output. Because the regulated voltage of a linear regulator must always be lower than input voltage, efficiency is limited and the input voltage must be high enough to always allow the active device to drop some voltage.

The best Raspberry Pi power supply SchematicLinear regulators may place the regulating device between the source and the regulated load ( a series regulator), or may place the regulating device in parallel with the load (shunt regulator). Simple linear regulators may only contain a Zener diode and a series resistor; more complicated regulators include separate stages of voltage reference, error amplifier and power pass element. Because a linear voltage regulator is a common element of many devices, integrated circuit regulators are very common; linear regulators may also be made up of assemblies of discrete solid-state or vacuum tube components.

What I used for my custom PSU is a relatively new devices, which is rated by audiophiles to achieve similar measures to a battery, amazing. Isn’t it? I’m talking of the LT3080. What we’re gonna do is basically find a suitable transformer to get an AC voltage of, let’s say, 12 volts. Then, use a single resistor or a trimmer to set the desired output voltage. It took me some hours to get it finished, but I’m pretty pleased with the result.

 

For more detail: The best Raspberry Pi power supply


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