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Variable Voltage Power Module

Powering my projects can be a challenge. This may be my future go-to solution…

Powering electronics projects are always challenging. This Variable voltage Power Module was designed to solve such a problem for a specific project that I am working on. The ESP32 and their smaller cousin the ESP8266 are pretty well known for their high power requirements. Having used quite a few of these in various projects over the years, I wanted a power module that can supply me with enough current to keep these hungry little chips satisfied. I also needed variable voltages with more modest current capabilities, to drive LED COB modules for example.

The idea thus came to me to combine two recent projects, that I have been using together on the bench with great effect. These two are the Variable Breadboard Power Module, based on the LM317G, and the DC-DC Buck Converter that I designed a short time ago. Between these two devices, I can deliver up to 3A at 3v or 5v, or a variable voltage at up to 1.5A.

Let us take a look at what exactly was done here.

What is on the PCB?
The PCB consists of 3 independent power circuits, the first of which is a DC-to-DC Buck module, based on the MP9943 from MPS. This chip can source up to 3A at a preset voltage. In my case, I chose 3.3v and 5v, as I use those the most. The second and third parts are a mirrored section, with the humble LM317G at their hearts. These are set up as variable voltage regulators, with their outputs adjustable via R10 and R13. These two can source two independent voltages, from about 1.0v right up to about 11.5v ( if VCC is 12V) at a respectable 1.5A or current. All of this is powered by a single 12v Power supply. Note that the 12v supply should be capable of sourcing at least 3A of its own…”

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