Power category

USB To 12V Boost Converter

This project provides 12V output from any USB power source, like PC USB port, USB adapter or power banks. LM2577ADJ boost converter IC is the heart of the project. The IC can handle load up to 800mA, it’s advisable to use only 200mA load on output to be on the safe side. The LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable. Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and fly back transformers designed to work with these switching regulators. Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and under voltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

USB To 12V Boost Converter – [Link]

Wireless power in AA battery format

Ossia has created the world’s first wirelessly-powered alternative to disposable AA batteries. The “Forever Battery” puts a long distance wireless power receiver into an AA battery format. The technology can receive up to 4W from a nearby RF transmitter (Cota transmitter), and includes a data link. [via]

Forever Battery bridges the gap between the battery-wire age and the wireless power era,” said Mario Obeidat, CEO of Ossia. “When people see how Cota Real Wireless Power can be implemented in a AA battery, they will start to see the vision of Cota everywhere. The Forever Battery will create awareness of Cota and provide confidence that devices will be powered when it matters.

Programmable Power Supply Using OPA548

Project provides 1.2 to 20V DC output with current limiter adjustable to 0-5A. I have tested the circuit with 250mA output without a heat sink. Project is capable to drive 3A continues load and 5A peak, large size heat sink required for full load. The tiny power supply based on low cost OPA548 high-voltage and high-current operational amplifier is ideal for driving a wide variety of loads. The project provides excellent low-level signal accuracy and high-output voltage and current. The circuits operate with single supply 24V DC and logic supply 5V DC. The IC is internally protected against over-temperature condition and current overload. Trimmer potentiometer PR1 sets the output voltages, PR2 helps to set the current limit 0 to 5Amps.
Programmable Power Supply Using OPA548 – [Link]

Grid-connected solar microinverter reference design

A PDF from Microchip on the theory behind inverter design connected to grip power.:

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required. This algorithm determines the maximum amount of power available from the PV module at any given time. Interfacing to the grid requires solar inverter systems to abide by certain standards given by utility companies. These standards, such as EN61000-3-2, IEEE1547 and the U.S. National Electrical Code (NEC) 690, deal with power quality, safety, grounding and detection of islanding conditions.

Grid-connected solar microinverter reference design – [Link]

uBoost Single AA to 3.3v 100mA Power Supply

µBoost is a Single AA powered, 3.3v 100mA power source and flashlight and it can run low power devices.

µBoost is small, portable, 3.3v 100mA power source for low power devices like Arduino Mini. It has white power LED and can usable as flashlight. Also it has “Battery OK” indicator that asserts when the battery voltage drops below 0.9v.

There is a 3mm hole on top, so you can hang it easily. You can simply turn it on/off by pressing the power button. It works as flip-flop.

uBoost Single AA to 3.3v 100mA Power Supply – [Link]

24-48V to 5V – 3A DC-DC Converter

24-48V input voltage range 3A output current DC-DC Converter using BD9G341AEFJ IC from ROHM semiconductor. This IC is ideal for high voltage to low voltage converter with 3A output current. Pin configuration of the board with 3 Pin horizontal mounting of the regulator is similar to LM7805 LDO regulator and is suitable to use this IC as replacement which can provide more current and take high voltage input.

Different voltage output are possible by changing few components. Refer to datasheet for the same. Example circuit can provide 5.1V/3A with input supply range 24-48V DC and operating frequency 200 KHz.

24-48V to 5V – 3A DC-DC Converter – Link

15V 1A Dual Output Flyback DC-DC Converter

+/-15V 1A Dual output DC-DC converter is a tiny board built using Transformer from Renco and LM2587-ADJ IC from Texas instrument.  Input supply 18-36V DC.  The LM2587 regulators is monolithic integrated circuit specifically designed for fly back, step-up (boost), and forward converter applications. The power switch is a 5.0A NPN device that can stand-off 65V. Protecting the power switch are current and thermal limiting circuits, and an under voltage lockout circuit. This IC contains a 100 kHz fixed frequency internal oscillator that permits the use of small magnetics. Other features include soft start mode to reduce in-rush current during start up, current mode control for improved rejection of input voltage and output load transients and cycle-by-cycle current limiting. An output voltage tolerance of ±4%, within specified input voltages and output load conditions, is ensured for the power supply system.


  • Supply Input 18-36V DC
  • Output +/-15V DC, 1Amp
  • On board trimmer potentiometer for Fine voltage adjust
  • Operation Frequency 100 KHz

15V 1A Dual Output Flyback DC-DC Converter – [Link]

3A Thermoelectric Cooler (TEC) Driver

3A TEC Driver Module is a complete power stage solution to drive Thermoelectric Cooler (TEC). The required DC voltage input controls the output current. It consists of the Texas instruments DRV593 power driver IC, along with a few discrete passive components required for operation. It also includes jumpers for configuring the features of the device, LEDs for fault monitoring, and an output filter. The 4 Pin header connector  for the inputs, 4 pin header connector for  output, and 4 Pin header connector for power supply, provide ease of connection to any system, from an existing design to a bread-boarded prototype. Connect a dc control voltage to CN1 Pin 3 (IN+), ranging from ground to VCC. The Pin 7 of the IC is held to VCC/2 with a resistor voltage divider, as shown in the schematic. Therefore, a dc control voltage of VCC/2 provides 0-V output from PWM to H/C. Input DC voltage range is 1.2V to 3.8V when supply voltage is 5V and 1.2V to 2.1V when supply voltage is 3.3V.


  • 3A Maximum Output Current
  • Low Supply Voltage 2.8V To 5.5V
  • Frequency 500 KHz (Refer to Note To change Frequency)
  • High Efficiency Generates Less Heat
  • Over Current and Thermal Protection
  • Fault LED for Over Current, Thermal & Under Voltage Conditions
  • When J3-Jumper is closed, the board is configured for 500-kHz operation.

3A Thermoelectric Cooler (TEC) Driver – [Link]

Harvesting Sound Energy From Passing Cars

by Mechanical Attraction @ instructables.com:

There is energy everywhere around us and in many different forms. Many devices have been developed to harvest light, wind, waves, and more. One unusual place of energy harvesting is from passing cars. As cars pass by some of their energy is released in form of sound. Even though the overall energy maybe small it can be harvested. In this Instructable I will show how to apply the solution of Euler–Bernoulli beam theory to design a cantilever beam to oscillate at such a frequency to adsorb sound waves as well as converting its mechanical motion into electricity.

Harvesting Sound Energy From Passing Cars – [Link]

White Paper: Cut the Cord with Power over Ethernet (PoE)

Providing AC power to each device individually is an extra cost especially for organizations when installing IP cameras, VoIP phones or network access switches and routers in the facilities. To help in this way some modern protocols, like USB and Ethernet, provide the power over the same data cable. However, USB is not designed for networking and long distance network applications. Besides that, the 900 mA at 5V in USB 3.0 is suitable for low-power devices like external hard disks but can’t provide enough power for high-power devices like switches and other network instruments. For these reasons, PoE (Power over Ethernet) can be the best choice.

CAT-5/5e twisted-pair Ethernet cable. Image courtesy of: CableOrganizer

PoE can provide power up to 30W beside data connectivity on any standard CAT-5/5e twisted-pair Ethernet cable, and supports 10Base-T, 100Base-T, 100Base-TX, and 1000Base-T Gigabit Ethernet interfaces.

The LEX Computech 3I390NX Series

As an example of an SCB (Single Computer Board) that provides PoE on its ports is a board called 3I390NX from LEX COMPUTECH which is based on the latest Intel Pentium Processor N4200/ N3350/E3950 Apollo Lake processor family. The Ethernet ports are provided by the Intel Ethernet controller i1211-AT.

3I390NX SCB features are:

  • Intel Apollo Lake N4200/N3350/E3950 CPU/chipset.
  • On Board 4GB DDR3L.
  • Display: HDMI, DP, VGA & eDP.
  • 5 x GbE (4 x PoE) LAN.
  • 2 x Mini PCIe.
  • 6 x USB.
  • HD Audio.
  • 2 x COM (1 x RS232 / 422 / 485 port (external), 1 x RS232 / 422 / 485 port (internal)).
  • Hardware digital Input & Output, 8 x DI / 8 x DO.

To know more about this SCB you can preview the full white paper published on IEEE Spectrum, or download it directly from here.