Problem You need to select a power supply for your Raspberry Pi. Solution see
Track the 230 VAC power line with your favorite HW using a small, efficient, and inexpensive circuit.
Things you should know using ESP8266 WiFi module for its safety and easiness as it's very delicate module to use.
This is a model circuit that can control the speed and the direction of a dc motor without the h-bridge ( it's an alternative to h-bridge ).
There are many charge controllers available, but ordinary cheap ones are not efficient enough to use with maximum power from solar panels.
Have someone pulling the plug on your project, or perhaps an unstable or unreliable power supply? Here is the fix!
CAN bus hack for reading the battery diagnostics form an electric car.
Get your essential appliances off the grid with just one solar panel
This very simple and inexpensive circuit will reset the fuses on a bricked ATtiny chip. Once programmed, no Arduino is required!
This hack is a proof of concept that shuts off power only to the level of the house that has been flooded, allowing for normal use elsewhere
A simple and inexpensive solution is to use a 'mobile power bank'
After you read this post, your projects will never run out of power after a power outage.
Bridging the gap between professional and DIY/hobbyist bench power supply.
This solar powering unit is a time-switching, battery-powered, solar-charged circuit for Arduino.
Demonstration project to show the lowest power losses in commutating half-bridge drive also working over varying reactance and current.
A tattoo artist friend of mine and I were discussing some of the limitations of current tattoo power supplies. I custom built her one.
This project is a "from scratch" DC regulated benchtop power supply intended to be used by an electronics hobbyist.
A compact, feature-rich smart UPS for Raspberry Pi boards.
A symmetric power source for audio amplifiers controlled by the Arduino's PWM with max output +-30v 10A.
If you have 9v battery but you need constant 5v power supply. Then this is the easiest way to make it.
With a code size of 1KB on an ATtiny13A MCU, this tiny module measures voltages up to 22 volts and current up to 5 amps.
Today we don't break anything, we open it and have a look.
I repurposed a USB current/voltage monitor dongle I bought on eBay to display the voltage and current of my homemade power supply.
How to make a variable step-down DC to DC converter using TPS54331.