This power-supply sequencer senses a loss of the main supply voltage and, by controlling the two FETs, automatically switches the load to the secondary (backup) supply.
The FET-OR connection for power supplies - [Link]
This video covers the basics of diodes, bridge rectifiers, and how to build simple unregulated AC to DC power supplies than can handle a few mA up to several Amps. Diode Tutorial & How to build an AC to DC power supply - [Link]
How to build your own linear adjustable power supply based on LM317. In this tutorial I’ll explain how linear power supply works, what parts it consists of and a lot of small details, like how to calculate smoothing capacitor value, or how to choose a transformer. Plus you’ll see how to build an actual power supply.
LM317 Simple Adjustable Linear Power Supply - [Link]
Simple Linear Adjustable Power Supply Tutorial (Based Around LM317) by JumperOneTV… – [via]
Adjustable LM317-based power supplies are an easy way to get custom voltages for your benchtop. Also check out the MIC2941 which has some nice benefits such as ultra-low dropout, 1.25A current output and a separate biasing pin. Its nearly a drop in replacement for the LM317 – albeit a little more expensive.
Simple Linear Adjustable Power Supply Tutorial - [Link]
SQKYbeaver posted a linear bench power supply in the project log forum. [via]
i have been working on a linear bench power supply, and have come to the conclusion that the cost of parts will be more than what i cam buy an assembled one for, however i will share what i have come up with so far so that any one interested will be able use what i have started.
DIY bench power supply – [Link]
This project describes a home made power supply for a small server computer. It uses a toroidal power transformer (not the conventional transformer) to step down the mains AC voltage. The advantages of using a Toroidal is it is quiet, efficient and smaller in size. The transformer output is then rectified and capacitive filtered. DC regulation is achieved using PTN78020 for the 12v supply, and PTN78000 for the 5V one.
DIY power supply for home server computer – [Link]
Embedded-Lab.com has just posted a new project called “Multi-function power supply”. It is not just a simple power supply but it has built-in Volt-, Current-, and Frequency meters. The beauty of this project is that while you are prototyping your circuit, you can continuously monitor how much current your circuit draws at a specified operating voltage. This way you will know in advance how much power your design will require. The built-in frequency counter can measure frequencies up to 50.0 MHz.
DIY Multi-function power supply unit – [Link]
Here’s a design for a digitally controlled power supply: [via]
I’ve built quite a few power supplies over the years; it’s an almost vital tool for electronics. It’s been my plan to built one which would drop the analog potentiometers in exchange for digital control with a microcontroller. There are many advantages to it as well as disadvantages but I believe it is worth the effort.
Digitally controlled power supply - [Link]
This project is a 12V 2A AC to DC power supply using LM7912 and transistor 2N3055.
12V 2A Linear Power Supply – [Link]
An appliance of some kind is in technical terms a load – it draws power. We can simulate this using a device, a dummy load, that draws power at a known rate. Dummy loads are usually nothing more than a large resistor. The supply voltage is dropped across the resistor and the energy contained in the supply current is dumped as heat – often an awful lot of heat! [via]
ELV Dummy Load for Power Supply Testing - [Link]