Power supply category

LiPo breadboard power supply

Versatile And Open Source LiPo bBattery Breadboard Power Supply

Orlando Hoilett from Calvary Engineering LLC designed a  versatile Li-Po battery breadboard power supply and wrote an Instructables on it. This power supply outputs 3.3V to the breadboard and takes input from a single-cell LiPo battery. The breadboard power supply also has the ability to charge the battery without needing to separate it from the circuit board. More importantly, this project is licensed under Open Source Hardware which means anyone can modify, distribute, make, and sell this design.

LiPo bread board power supply
LiPo breadboard power supply

Key Components

The complete BOM is available at the GitHub repository.

  • JST connector
    This connector connects directly to the LiPo battery.
  • 3.3V regulator, AP2210K
    3.3V logic is getting increasingly popular among electronics hobbyists and engineers. Also, boosting 3.7V of a LiPo battery to 5V can induce quite a bit of switching noise on the power supply. Linearly converting 3.7V to 3.3V is the best way to avoid this problem.
  • Battery Charger, MCP73831T
    This power supply has a charger built into the board so you can charge the battery without removing it from the power supply.
  • Voltage Selection Jumper
    The voltage selection headers are 3 pin male headers and they are labeled as 3.3V (or VReg) and VRAW (or LiPo). Connect the center pin to 3.3V to get power from the regulator. Connect the center pin to VRAW to get power directly from the LiPo battery.
  • DPDT Switch
    This switch lets you power down the board without removing the battery.
  • LED indicators
    LEDs are used to indicate the current status of the board.


This board breaks out the LiPo battery to the breadboard power rails on both sides. It has a DPDT switch to power down the board. The AP2210K IC has an ENABLE pin which is pulled down to the ground using the DPDT switch in order to enter the low power mode. In low power mode, the regulator and all the LEDs get disabled and draws almost no current from the LiPo. More about the AP2210K regulator IC is on this datasheet.

LiPo breadboard power supply schematic
LiPo breadboard power supply schematic

Another great feature of this breadboard power supply as mentioned earlier is, it incorporates an MCP73831T LiPo battery charger IC. It is a widely used PMIC (power management integrated circuit) for charging LiPo batteries. The LiPo battery should be connected to pin 3 (VBAT) and 5V should be applied to pin 4 (VDD).

The chip starts charging as soon as it detects 5V input and stops charging when the battery is full. Charging current is limited to USB standard i.e. 100mA by connecting a 10.2K resistor between pin 5 (PROG) and ground. So, it’s completely safe to charge the battery from your laptops USB port. Other host microcontrollers can check the battery status using pin 1 (status pin) of MCP73831T.

PowerPlant, A Personal Power Assistant

Imagine you won’t need electricity mains wherever you are outside! PowerPlant by Nuuq is trying to solve this issue by providing its charging mains-alike power bank. PowerPlant is light enough to be convenient to carry, suitable for you backpack and is TSA approved. Also, it is powerful enough to charge loads of device with its 95 Watts power output.

Check this video to know more about PowerPlant:

Power on the go!

Fortunately, PowerPlant includes a universal plug input, a replaceable battery, plus an inner temperature protection. In addition, it will provide you with easy read via its LCD plus fast charging. Furthermore, it has many competitive advantages compared to similar products.

To summarize, below are the full specifications of PowerPlant:

  • Universal plug for 2 & 3 pin plugs (ideal for USA, UK, Europe and Australia)
  • Output 19v/1.58A 5v 2.4A
  • Output: AC 100 – 240v/95W (max)
  • Modified Sine Wave Inverter
  • Replaceable 20100mAh lithium-Ion battery
  • 2 x 2.4A 5v fastcharge USB ports
  • 1 x USB-C
  • 1 x 19 Volt fast charge charging port
  • LCD display with battery charge, temperature, AC, DC and In/Out display
  • IP4 Splash-proof water resistance

PowerPlant is now live on a crowdfunding campaign on Indiegogo. Amazingly, it has achieved 500% of its goal and still has 11 days to go. Finally, PowePlant is available for $150, you can check the campaign for more details.

Isolated 24V to 12V 10W Flyback Power Supply

maximintegrated.com power supply experts have a reference design of a 24V to 12V flyback converter.

Maxim’s power supply experts have designed and built a series of isolated, industrial power-supply reference designs. Each of these power supplies efficiently converts 24V into useful voltage rails at a variety of power levels. Every power rail is isolated with a readily available transformer from multiple, global vendors, providing for quick, convenient transformer selection. Each design has been tested for load and line regulation, as well as efficiency and transient performance. As with all Maxim reference designs, the BOM, schematics, layout files, and Gerber files are all available. In addition, boards are available for purchase; most boards feature through-hole pins for immediate board placement and accelerated prototyping.

Isolated 24V to 12V 10W Flyback Power Supply – [Link]

Linear Lab Power Supply with digital meter

@ instructables.com build a nice power supply for his lab. He writes:

From my point of view one of the best ways to get started in electronics is to build your own laboratory power supply. In this instructable I have tried to collect all the necessary steps so that anyone can construct his own.

All the parts of the assembly are directly orderable in digikey, ebay, amazon or aliexpress except the meter circuit. I made a custom meter circuit shield for Arduino able to measure up to 36V – 4A, with a resolution of 10mV – 1mA that can be used for other projects also.

Linear Lab Power Supply with digital meter – [Link]

Digital Battery Operated Powersupply

ThomasVDD @ instructables.com writes:

A while back I built a powersupply from an old ATX PSU, and while it works great, I wanted to step up my game with a digital powersupply. As already said, it is powered by batteries (2 lithium cells to be precise), and it can deliver a maximum of 20 V at 1 A; which is plenty for most of my projects that require a precise powersupply.

Digital Battery Operated Powersupply – [Link]

400V – 5A Power Supply For Brushless Motor Drivers

Although the power supply design is specific to the Brushless Servo Drivers mainly for IPM Modules, the concepts and circuit design may be used for any power supply requires high voltage output up to 400V DC and 5 Amps. The power supply is an unregulated design with an option to allow connection to either 120V or 230V mains and also it can work with lower voltage for audio amplifiers by increasing capacitor value. The design uses fully integrated bridge rectifier, and multiple bus capacitors for low ripple, noise suppression, and provides high current reservoirs. Additionally the dc supply line have bleeder resistor R2 and R3 to drain the large reservoir capacitors PCB, mounted fuse holder provided  for short circuit and over current protections, low ohm NTC used for inrush current at power start up,  C1, C12, TX protects  against turn on/off spikes and EMI noise reduction. This power supply can be used to drive Tesla Coils, Induction heaters, DC Motor drivers, Brushless DC motor driver.

400V – 5A Power Supply For Brushless Motor Drivers – [Link]

SEPIC/Ćuk converter sprouts second output

by Gheorghe Plasoianu @ edn.com

Many applications require positive and negative supply voltages, with only one voltage requiring tight regulation. This Design Idea describes a dual-output, hybrid SEPICĆuk converter whose positive output voltage can be lesser or greater than the input voltage. The unregulated negative output is a mirrored replica of the positive output.

SEPIC/Ćuk converter sprouts second output – [Link]

Reference design – USB Type-C charger delivers 18W

Graham Prophet @ eedesignnewseurope.com discuss about a 18W USB power supply reference design.

This joint reference design describes an 18W, USB PD compliant, AC-DC power converter. The design, titled DER-567, pairs the WT6630P USB Type-C PD controller from Weltrend with Power Integrations’ InnoSwitch-CP off-line CV/CC flyback switcher IC, to produce a compact and highly energy-efficient standards-compliant power adapter, that PI says will deliver faster charge times for the larger batteries required to power next-generation mobile devices.

Reference design – USB Type-C charger delivers 18W – [Link]

StromPi, The Uninterruptible Power Supply for Raspberry Pi

It seems evident that the Raspberry Pi and its clones have filled an enormous hidden need. The digital performance of such micro-computers is exceptional as long as they are used without any special dependence on power requirements, that is to say near an electrical outlet with power! Faced with the vagaries of the analog world, these tiny cards that fit in the palm of your hand are not as beefy as that. Their dependence on their power supply has highlighted a new need, well identified by the manufacturer JOY-iT. StromPi, their adaptable uninterruptible power supply (UPS) mini card lets you use a Raspberry Pi under conditions of unusual or unstable power, without taking up much space, and without risk of data loss in case of a power cut.

Two working modes are offered:

  • UPS (uninterruptible power supply), i.e. no break power
  • WIDE, which allows an extended range of input voltage

With the following characteristics

  • wide range of DC input voltage, from 6 V to 61 V in WIDE mode
  • 5 V power input on microUSB connector
  • maximum USB output current of 3 A
  • very low standby current
    • (in UPS mode): 20 to 80 μA (that’s between 175 mAh and 700 mAh per year)
    • (in WIDE mode): 3 to 7 mA

In the case of loss of power, the StromPi backup power card not only starts the process of data backup before the Pi is switched off, but it can also guarantee startup once the power is restored (this function may be deactivated with a jumper strap).

When that happens, you can even select to be informed by an email sent by the Raspberry Pi program (which you can download).

Source: Elektor

3.3V @ 1.5A Buck Regulator

The circuit presented here is based on LTC3601, a high efficiency, monolithic synchronous buck regulator from Linear Technology. The circuit operates at an input voltage ranging from 4V to 15V, this makes it suitable for a wide range of power supply applications. It is capable of producing a output voltage of 3.3V. Burst Mode operation and forced continuous mode are the two types of operational modes available in LTC3601.


  • Input(V): 4VDC to 15VDC
  • Output(V): 3.3VDC
  • Output load: 1.5A
  • PCB:35mm X 25mm

3.3V @ 1.5A Buck Regulator – [Link]