The circuit provided here is a transformer-less non-isolated power supply which is capable of delivering an output of 12V at 120mA current for an input voltage varying from 85VAC-265VAC. The LNK304 is the heart of this circuit which supports buck boost and flyback topologies. This project is low in cost and simple when compared other tramsformer-less power supplies.
Envox Experimental Zone (EEZ) is an open hardware and open source development website, that creates and shares various open source hardware and software projects using as much as possible open-source tools and technologies.
One of their projects is the programmable bench power supply ‘EEZ H24005’. The goal is to make a reliable, modular, open and programmable power supply, that can be used for various tasks starting with powering breadboard, charge batteries of various types, or to be used as an educational tool and science experiments.
The EEZ H24005 is a DIY power supply unit consists of four PCBs and SMT electronics components except some power resistor, AC/DC adapter, and power regulators. Only two ICs need hot air soldering station to mount, while the remaining parts can be simply mounted with soldering iron.
In addition to modularity, programmability, openness, and DIY, reliability was one of the key features and design guidelines of the designing process. Because as a sourcing device, the PSU has to be designed in the way that no dangerous oscillation in voltage or current is present over the long period of deployment. That includes border case of turning the PSU on and off, applying or disconnecting load, etc.
Here is some of the main features of H24005:
Modular design that allows combining modules with various performance and capability and creation of multiple output solution
Voltage regulation (CV), 10 mV resolution
Current regulation (CC), 10 mA initial resolution
Various current single range operation (0-5 A default, 0-3 A or 0-4 A per channel)
15-bit data acquisition resolution
Real-time clock (RTC) with supercap/battery backup
SD-card as an additional storage
Ethernet support for remote control
Simple DC output protection (reverse voltage, over-voltage)
Since it is an open source project, all files, designs, source codes are available at the Github repository. Also a detailed building guide is available at the official website. But if you want to get H24005 but not interested in making it, you can order yours through OSHPark. There is also a CrowdSupply campagin on going.
Bob @ electrobob.com tipped us with his latest project. It’s about a power supply tester.
What does one do when designing a power supply? Well, build a power supply tester, of course. One of the simplest things to build is a constant current load. This will allow for testing of the endurance of the power supply, as most of the designs out there are using slow components.
However, I wanted to make a better one: one that I could hook up to my Analog Discovery and generate a test waveform to be able to connect and disconnect the load fast. This is a weekend project, so all parts are not the best for the purpose, just what I had around.
Rui Cabral tipped us with his latest video. It’s about a dual output power supply build in a 3D printed enclosure. Main parts used are a 100W AC-DC converter (110V 220V to 24VDC 6A) and LM2596 DC-DC Buck converter constant current voltage adjustable module. The power supply has two voltage outputs, a fixed 5V output and a variable output (1-24V). The enclosure 3D files are available here.
DIY power supply with 3D printed enclosure – [Link]
Audio projects become smaller over time with the rapid advancement of technology. A traditional power supply is still considered large compared to audio projects size constraints and it may not fit such delicate applications that need to deliver a good sound with zero noise.
Jan Didden, audio specialist who is known for his own publications Linear Audio, has came up with a new idea that can help in perfecting audio projects. The SilentSwitcher is a 55 x 31 mm special power supply module designed to supply clean power to high-end analog and digital audio circuits.
“One goal of this power supply that it doesn’t need to connect to the mains, you can use it with a USB charger or with a power bank… All problems with ground loops and mains born noise are not existing”- Jan Didden, the designer of The SilentSwitcher
The SilentSwitcher uses a combination of switching and linear regulators to generate a stable and noise-free supply voltage. The module can be powered from a 5V USB adapter, or from a 5V power bank for complete isolation. It delivers ±150 mA and a choice of 6V, 5V or 3.3V at 0.5 A to benefit most of your applications. The absolute maximum input voltage is 12VDC but in normal operation it is preferable to limit it to 10VDC.
Outputs (analog): +15 and -15 VDC at 150mA* each;
Output (6/5/3.3V): selectable 6, 5 or 3.3 VDC at 0.5A*;
Output noise (6/5/3.3V): less than 1mV broadband
Output impedance (analog): less than 10mΩ (+15V) and 80mΩ (-15V) at 20kHz
Output impedance (6/5/3.3V): less than 3mV drop with 100mA current step.
15V output at 150mA are provided thanks to the very low noise linear regulators of Texas InstrumentsTPS7A47, TPS7A33 that suppress all the noise from the switching regulator by a factor of one thousand even at 1 Megahertz. Such chips have driven zero noise to switcher technology and have shown incredible quiet and low noise performance.
Jan Didden talking about his product
The well designed board will help in keeping all elements quiet and avoiding excess radiation. There are 2- and 3-pin headers on the PCB to connect the load, and a 2-pin header for an On/Off switch. The connection to the 5V source is through a B-type USB connector or a standard 2-pin screw-type connector block. You can mount the PCB on the back of your enclosure with a hole cut out for the USB-B – no further input wiring required.
This power supply will be a great companion for your project! No need to think about wiring or transformers, and you won’t face any issues like mains hum or mains earth loops.
The SilentSwitcher is live on a Kickstarter crowdfunding campaign and there are only few hours left to go! You can get your own SilentSwitcher for $59 and you will receive a fully assembled and tested board.
Switching technology devices and integrated circuits are growing fast providing solutions that obtain power for different kind of circuits and devices, and they are proposed in different variations. A useful little known kind which is suitable for mixed supply systems is called SEPIC,single-ended primary-inductor converter.
Torpedo is a switched-mode power supply with a SEPIC configuration which is produced by Open Electronics, an open source solutions producer and the brainchild of Futura Group Srl. It supports three different wide-range voltage sources, battery, USB, and external source from 3 to 20 volts with up to 1 A output current and integrated LiPo battery cell charger.
Torpedo comes with these features:
Triple power source, that is to say: the USB, the battery and an external one
Wide range of values as for the input voltage: from 3 to 20 volts
Minimum output current of 500mA, with the possibility to reach 1A and more, via an external source
High efficiency, above 70% and possibly above 80-90%
Single-cell LiPo battery charger incorporated
A transition from battery power to another source that is without interruptions
5 V output with high stability, having a low ripple and when varying the load.
Torpedo’s circuit structure can be functionally divided into three different parts; Input Stage, Battery Charger, and SEPIC Converter.
At first, the Input Stage is composed of two diodes and a MOSFET transistor. This set forms a power source selector by allowing the highest voltage power source to pass through Vin pin and prevent it from going to another input having a lower voltage.
The Battery Charger is based on the MCP73831-2 integrated circuit, that is envisaged for charging single-cell LiPo batteries having a voltage of 4.2 volts. It comes with a red LED indicating the statues of charging, and a two-resistor bridge giving two different output current, 100mA and 500mA.
The SEPIC Converter in general is a DC/DC converter which control its output to be greater than, less than, or equal to that at its input. In Torpedo circuit, the SEPIC integrated circuit contains 1.2Mhz oscillator with variable duty cycle, a low-RDSON MOSFET, and a feedback circuit. This combination provides constant 5V output voltage from variant input voltage between 2.5V to 20V.
EspoTek Labrador is a small, portable, USB-connected electronics lab-on-a-board that includes an oscilloscope, waveform generator, power supply, logic analyzer, and multimeter.
The EspoTek Labrador plugs directly into a solderless breadboard and connects to any Windows, Mac, or Linux computer via microUSB. A custom software interface lets you see and interact with your waveforms on-screen. Careful planning and a lot of work has been put into making the interface intuitive for those new to electronics, while keeping it powerful for those familiar with the instruments. Experienced engineers, don’t fear – you can do things like manually adjust the ADC gain and UART parameters. These kinds of function have just been moved away from the main screen, keeping things clean and simple for newer users.
EspoTek Labrador – Oscilloscope, Signal generator, Power supply in one tiny board – [Link]
A lot of power supply designs are here and there on the Internet, but not all of them have constant current and voltage modes. You can read the following Q&A in electronics.stackexchange to learn what constant current and voltage modes mean.
Elia over Hackaday.io built a linear bench power supply with the following features:
Output voltage range: 0 – 15V.
Output current range: 0 – 3A.
Constant voltage with current limiting and constant current modes.
LT3083 the adjustable 3A low dropout regulator from Linear technology is used to provide the output voltage.
To reduce the power dissipation in the linear regulator, supply voltage is not connected directly with the adjustable LDO regulator input. Elia added a stage to reduce the input voltage of LT3083 to (Vout+2) using a buck converter. This Buck converter, TI TPS54331, is configured to follow the output voltage of the adjustable regulator plus 2 volts as an output voltage of the buck converter.
ATmega8 MCU is used to drive the 16*2 LCD, read values from the rotary switch STEC12E08, read user buttons and to produce the reference PWM signals for voltage and current.
These PWM signals are converted to analog value, the way used to convert the PWM signal to an analog value proportional with PWM is by using “resistor, a capacitor and an opamp”. LM334, an adjustable current source, used in the output voltage of LT3083. Elia said in a log, it is needed for stable operation, the LT3083 needs a minimum load current of 1mA.
Design Files and Source Code
ElbSupply is an Open-source hardware project. You can download the source files from the GitHub repository.
Linear Technology’s LTC3256 is a high voltage low noise dual output power supply, which takes a single positive input and generates 5V and 3.3V step-down supplies with high efficiency and no inductors. by Julien Happich @ edn-europe.com
The device features a wide 5.5V to 38V input voltage range and includes independently enabled dual outputs: a 5V 100mA supply, and a 250mA 3.3V low-dropout (LDO) regulator, for a total of 350mA available output current.
Dual output step-down charge pump operates without inductors – [Link]
As we know, PSU in computers provides various DC voltages, 3.3V, 5V and 12V. These 3 levels are the most common ones needed in our labs, so usually PC PSUs are used by a lot of makers and hackers as their personal bench power supply. The PSU has a standard connector called ATX, you can reach all of the voltages levels using it.
[Supercap2F] hacked his own PSU into a bench power supply and published the project details. Supercap2F’s power supply design include:
16*02 LCD as a user interface.
Three switches for user control (select/move).
Relays controlled by PIC18F1220 to switch outputs on/off.
Fused Outputs: +3.3V, +5V, +12V and -12V.
[Supercap2F] published the circuit designs (PCB&SCH) and source code for PIC18F1220 over Github.