The page below shows two soft start power supplies. The output voltage of these power supplies slowly increases to the desired output. The output voltage rises slowly and reaches 15 V in 5 seconds.
Soft Start PSU – [Link]
This is a 9V power supply which will work even on power failure. It uses a rechargeable battery and regulators. A transformer with 15-0-15 AC volts output is required.
Battery Backup Supply – [Link]
This project shows how to build a Dual Variable Power Supply using LM317 and LM7805. It has two different outputs.. one stable at 5V and one variable, rated at 1 ampere each. The power comes from a transformer. Schematic and PCB is available on Eagle format.
A lot of emphasis was put on making this power supply very stable, a big 4700uF cap takes care of the ripple, then come the regulators, after that a 220uF clean any noises that the regulator might have let pass. The polyester capacitors do a more subtle filtering.
Dual Variable Power Supply using LM317 and LM7805 - [Link]
This is simple to build microcontroller controlled power supply that can switch between 5 (or 32 or more) preconfigured voltages between 1.2 to 33 volts dc and up to 3 amps. This guide will walk you through every aspect of the building process; however some basic familiarity with electronics and microcontrollers will be required to program the microcontroller.
Digital Multiple Voltage Power Supply - [Link]
A variable DC power supply is one of the most important tools for an electronics hobbyist. In order to carry out an experiment you need a reliable DC power source that can be varied according to the need of the experiment. Last week I felt I must have one on my workbench, and thought to make one for myself. This design is very simple but is great for powering almost all kinds electronic projects. It uses LM350 (a 3-pin IC) to generate a variable DC power supply. I would recommend to read the datasheet before doing this project.
Variable DC Power Supply (1.25 – 18V) using LM350 IC - [Link]
The following circuit Diagram of (DUAL VOLTAGE POWER SUPPLY ) can be used for Misc.. application. It requires a few components to built. The most important components of this circuit are REGULATORS. 1 : (AN) 7812 and 2 : (AN) 7912 AN7812 is the Positive Voltage Regulator.
Dual Voltage Power Supply – [Link]
The limitation of car supply voltage (12V) forces to convert the voltages to higher in order to power audio amplifiers.
In fact the max audio power x speaker (with 4 ohm impedance) using 12V is (Vsupply+ – Vsupply-)^2/(8*impedance) 12^2/32 = 4.5Watts per channel, that is laughable…
For powering correctly an amplifier the best is to use a symmetric supply with a high voltage differential. for example +20 – -20 = 40Volts
40^2/32 = 50 Watts per channel that is respectable.
This supply is intended for two channels with 50W max each (of course it depends on the amplifier used). Though it can be easily scaled up or the voltages changed to obtain different values.
Automotive 12V to +-20V converter (for audio amplifier) - [Link]
This is a very useful project for anyone working in electronics. It is a versatile power supply that will solve most of the supply problems arising in the everyday work of any electronics work shop. It covers a wide range of voltages being continuously variable from 30 V down to 3 V. The output current is 2.5 A maximum, more than enough for most applications. The circuit is completely stabilized even at the extremes of its output range and is fully protected against short-circuits and overloading.
3-30 V/2.5 A Stabilized power supply – [Link]
This PSU has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. Let us see what we have got here. The power transformer should be capable to deliver at least 25A at 17.5 to 20V.
13.8V 20A power supply - [Link]
This project is a power adapter that is able to convert any PC ATX PSU to an adjustable laboratory power supply ranging from 0V to 20V. Characteristics are:
- Output current: 4A-12V 2A-20V
- Input voltage: multiple PC ATX 2.0 connector
- Operating Frequency: 40kHz
- Effectiveness: 90%
- Output voltage: between 0V to 20V adjustable, auxiliary +12 V and-5V
- Protections: over current (4 A) in IC2
0V to 20V adjustable power supply using ATX PSU – [Link]