Rhys Goodwin @ rhysgoodwin.com wanted to automatically start up his GPS unit when he turn the key of his car. To achieve that he should apply 5 volt to pin 6 at the base connector of the Ipaq. In that way the Ipaq wakes up. This seems easy to do but that method has some problems. To manage these problems Rhys Goodwin rebuild the power supply with a 10 sec delay on the output to Ipaq using a circuit found online.
Ipaq Auto-wake for in-car Application – [Link]
LM2596 is a step-down (buck) Switching Regulator capable of delivering 3A of current and it is working at 150 KHz switching frequency. Using a few external components you are able to build a powerful power supply. It comes on 3.3V, 5V, 12V, and adjustable output versions.
Switching Power Supply Regulator with LM2596 - [Link]
This circuit is an overload protection circuit for a power supply. It is working by disconnecting the load when over current is detected. The circuit consists of three main parts: the current detect circuit, the relay control and the overload display. The current detect circuit consists of R5,R6,VR1 and T3, the relay control circuit consists of T1,R1,D1 and RY and overload display consists of R2,R3,LED1 and Q2. Check details on the link below.
Overload Circuit for power supply – [Link]
This article discuss about power supplies, what a power supply is and about Transformer-based AC/DC converters. Check it out…
A power supply is a device that supplies power to another device, at a specific voltage level, voltage type and current level. For example, when we talk about a 9VDC @ 500mA power supply can provide as much as 500mA of current and the voltage will be at least 9V DC up to that maximum current level.
What is a power supply? Transformer-based AC/DC converters – [Link]
This is a DC to DC converter for car power amplifier. 12V input generates +30V and -30V output for preamp or power amplifiers. Circuit uses SG3525 IC, Mosfets and switching power supply.
12V to +/- 30V DC to DC Converter - [Link]
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]