DIY Workbench Power Supply

Next Task: Design…

I’ve needed a decent, variable bench power supply fro some time. So I decided that creating y own would be a great idea, I can customise what features I want, and it actually works out more cost effective. My PSU needed to have various features including a high current output, and a variable voltage output. Like most of my projects, I followed theImage result for systems development life cycle systems development life cycle to plan and create my PSU. In doing this I can cover all the needed features and have good documentation to aid me along the way.

Plan:

As this is one of my own personal projects, I have the luxury of a deadline that’s not set in stone. This will allow me to ensure that the end product is of great quality, meets the specifications needed and works well. I don’t want to spend more that £20 on this project. This project doesn’t need to be too advanced, the components are cheaply sourced and the chassis will be 3D printed. To make the project easier, I’m going to try and source various an all-in-one component for the more advanced features. For example, I’ll use voltage display modules and Boost/Step down converters instead of voltage dividers and complex voltage detection circuitry. This will help save time and will probably work out more cost effective on the long run.

Analysis and Specification:

My current solution involves tapping into my 3D printers 12V 30A power supply, which works okay but I’d prefer a sperate piece of equipment, I also need to have the ability to work at different voltages to use different components and fix old electronics. To meet the above conditions, I have devised the following specification;

  • Moderately sized – So it has the ability to be relocated if needed
  • Solid, sturdy design – To ensure a durable build and quality feel
  • Variable High Current Output – For use with Li-Po chargers and other high current applications
  • 3A > Variable voltage output – For use in testing applications
  • Voltage and Current Display for Variable output – For easy use
  • 12V, 5V 3.3V and 24V outputs on a 5A >  rail – For use with fixed voltage applications
  • 2X common ground ports – For easy connectivity
  • Fused Rails – For protection
  • Main power Switch and LED – For easy use
  • 240V wall input – To avoid using an additional external PSU
  • Active cooling for the internal components – To keep everything cool and ensure longevity
  • Positive Pressure Cooling Environment – To prevent dust build up inside the unit
  • Potentiometer based voltage control – For easy use
  • Vent holes in chassis – For component cooling and airflow
  • Binding Post connections – For easy use
  • 5.5mm Power jack for different voltages – To allow alternative hookup methods
  • Exposed connection for different voltages – To allow for clip con style collections
  • Switches to control each output – For safe use

Design and Project Development

Components

  • 230V to 24V 10A Switching ATC PSU
  • 3D Printed Chassis
  • 4 x Binding Posts (Red and Black Pair)
  • Voltage & Ampers LCD display
  • 5x Rocker Switch
  • 4x LM2596 DC-DC Step-down module
  • 4x Addition heat skins for Step down modules
  • Green LED
  • Potentiometer
  • Female 230V Kettle Plug
  • Fuses: 1x 10A 2x 5A
  • 3x Fuse Holder
  • 40mm fan

Costs Spread Sheet Link

Dimensions

24V 10A PSU Dimensions  (terminals facing left): X = 19.7cm Y = 11.1cm Z = 4.85cm

Binding post: Binding screw shaft= M4 (4mm) Head= 11mm

Potentiometer shaft diameter = 6mm

Circuit Design

 

Casing Design

 

3D Modeling

3D Printing

 

Implementation and Testing

 

Evaluation

 

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