Power category

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.

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.

5V to Dual 12V Step Up DC-DC Converter Using LM2588-ADJ

Lots of op-amp based circuits require dual (symmetrical) power supply. This tiny circuit is a simple solution which provides +/-12V DC 300mA from single 5AV DC   input. The board is based on LM2588-ADJ IC from Texas instruments. Step up from 5V to dual 12V is the best part of the circuit since 5V is easily available.

The LM2588-adj regulator IC specifically designed for fly back, step-up (boost) and forward converter applications, this regulator are cost effective and simple to use due to minimum number of external components.  The power switch is a 5A NPN device that can stand-off 65V. Protecting the power switch are current and thermal limiting circuits, and an adjustable frequency that can be programmed up to 200Khz. other feature include soft start mode to reduce in rush current during start up, and current mode control for improved rejection of input voltage and output load transient and cycle-by-cycle current limiting.

5V to Dual 12V Step Up DC-DC Converter Using LM2588-ADJ – [Link]

New Batteries with 3 & 15 Times Energy Density

With the rapid growth of battery-based devices and tools, efficient energy storage systems are becoming more and more important. Of course there are many researches running around the world working on novel battery technologies. Two new cell technologies are working to deliver energy density of 3 and 15 times of conventional lithium cells.

The first is a group of scientists from Rice University, they solved the dendrite problem of commercial lithium-ion batteries providing a three times capacity rechargeable lithium metal battery. Dendrites are whiskers of lithium that grow inside batteries, and they can cause fires like those in the Samsung Galaxy Note 7. They are considered a major issue for next-generation lithium batteries.

Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites. Courtesy of the Tour Group.
Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites. Courtesy of the Tour Group.

The main idea of the research is to coat high conductive hybrid graphene and carbon nanotubes with metallic lithium. These low density and high surface area nanotubes have space for lithium particles to slip in and out as the battery charges and discharges.

“Lithium-ion batteries have changed the world, no doubt, but they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.”  – James Tour, leader of the research team

A prototype of a battery with 3.351 Ah/g capacity, retains 80% of the original capacity after 500 charge cycles.

In Japan, and especially at the NIMS (National Institute for Materials Science), another research is working to create a Lithium-air battery that has the highest theoretical energy density because it uses oxygen in air. Its capacity reaches 15 times of the conventional Lithium batteries.

The electrode material has an enormous surface area thanks to ​​carbon nanotubes. Researchers achieved 30 mAh/cm² capacity in the lab, which will be amazing if realized in a commercial product. Work is ongoing to produce real practical samples with high energy density and a system to filter impurities from the air.

Source: Elektor

Adjustable constant current source

Dilshan Jayakody has published a new build:

The current source introduced in this article is capable to handle current up to 6A with maximum input voltage of 50V. This is an operational amplifier based adjustable current source and it uses LM358 in a general voltage follower configuration. To handle large currents we use four 0.1Ω 20W resistors as “load resistor”, and those load resistors are drive through pair of 55N06 N-channel MOSFET transistors.
The power supply unit of this project is build around 9V x 2 (2A) step-down transformer and it is design to get regulated 12V DC voltage. In our design this 12V power source is used to drive LM358 Op-Amp and 12V cooling fan.

Adjustable constant current source – [Link]

6V Lead Acid Battery Charger using BQ24450

6V Lead acid (SLA) battery charger project is based on BQ24450 IC from Texas instruments. This charger project takes all the guesswork out of charging and maintaining your battery, no matter what season it is. Whether you have a Bike, Robot,  RC Car,  Truck, Boat,  RV, Emergency Light, or any other vehicle with a 6v battery, simply hook this charger maintainer up to the battery. The bq24450 contains all the necessary circuitry to optimally control the charging of lead-acid batteries. The IC controls the charging current as well as the charging voltage to safely and efficiently charge the battery, maximizing battery capacity and life. The IC is configured as a simple constant-voltage float charge controller. The built-in precision voltage reference is especially temperature-compensated to track the characteristics of lead-acid cells, and maintains optimum charging voltage over an extended temperature range without using any external components. The low current consumption of the IC allows for accurate temperature monitoring by minimizing self-heating effects.  In addition to the voltage- and current-regulating amplifiers, the IC features comparators that monitor the charging voltage and current. These comparators feed into an internal state machine that sequences the charge cycle.

6V Lead Acid Battery Charger using BQ24450 – [Link]

What Is Household Ground?

Image source: RimstarOrg Youtube channel
Image source: RimstarOrg Youtube channel

RimstarOrg published an interesting video on his Youtube channel to demonstrate why In north America you can find 3 holes in the electricity socket; which are hot, neutral and ground.

Image source: RimstarOrg Youtube channel
Image source: RimstarOrg Youtube channel

The hot wire goes to a breaker-panel and then to electricity grid and finally to a transformer somewhere. While the neutral line is connected with a bar in the breaker-panel and goes directly to the electricity grid and then to the transformer. Mostly, these wires’ colors are respectively black, white.

Breaker-panel — Image source: RimstarOrg Youtube channel
Breaker-panel — Image source: RimstarOrg Youtube channel

To understand why having a ground in household appliances is important, the video explained a use-case; a microwave-oven with 3 wires electricity plug where the electricity flows between the hot and the neutral, while the ground is connected to the external case. However, if the hot wire isolation gets damaged and attached to the case, the grounded case will make a low resistance path for the electricity. This will protect you from an electric shock because the electricity in this low resistance path will be very high forcing the breaker switches off.

Image source: RimstarOrg Youtube channel
Image source: RimstarOrg Youtube channel

Having a ground in the electrical system can play a role in the places where lightning can occur by forming a discharging path for charged cases in your house.
To understand more about household ground and other different meanings and applications of earth and ground watch the complete video below:


Source: Adafruit Blog