Build a Variable Lab Bench Power Supply
Introduction: Build a Variable Lab Bench Power Supply
Working on electronic projects at the workbench, whether prototyping with a circuit, powering a small desktop device, or simply testing a component, all require a specified source of power. Using power adapters and other DC sources such as batteries won't always be enough as they're only temporary power solutions. This is where the variable Lab Bench Power Supply unit comes in being a hands-down essential apparatus to have on any maker's workbench.
With this homemade variable Power Supply unit, you can set a specific voltage (0-36V) and current limit (0-5A) for that circuit you want to power. 134
The device even has some common fixed voltage outputs at the front as well. As a cherry on the cake, you may charge up to two Lithium-Ion cells at a time with the 2-cell automatic cut-off 18650 cell charger on the side! To top things off, all these power features internally are fully temperature regulated with the heat-activated fan seen at the top of the Power Supply Unit. Having all of these features handy, you'll be even more well-equipped in the world of hobby electronics.
Today, with this Instructable, you'll learn how to make a similar Power Supply of your own, the DIY way!
Resources:
Full circuit diagram: https://drive.google.com/file/d/1irprbFX7_oeV_-6inQfxwCJbcMkWcS6f/view
Power Supply's front and rear face blueprints: https://drive.google.com/file/d/1XNKHJ-Ro4WkKZqn6Q0eCUHvU8jWViU1o/view
MOSFET-based Temperature controlled switch - Circuit Diagram: (Credits to YT channel - ABTabi)
https://drive.google.com/file/d/1xT-7rCxKNZLwKLg-iPQoXNK4AownCvSo/view
Supplies
List of Materials & Parts:
• Numerical Control DC 6-55V to 0-50V 5A Step Down Power Supply Module - https://amzn.to/3GepraP
• 180W AC to DC 100-240V AC to 36V 5A DC SMPS Step Down Converter
• LM2596 Step-Down Buck Converter - amzn.to/386B1bv
• (x2) TP4056 Single Cell Li-Ion/LiPo Charger module - amzn.to/3wzs4zq
• 5V 3A Dual USB output charging module - amzn.to/3wBp1H8
• 5V LM7805 voltage regulator - amzn.to/3PApEJF
• Temp-controlled Switch board with MOSFET & Thermistor - Homemade
• (x2) Blue LED
• (x3) Red LED
• (x1) Green LED
• IN5408 3A Rectifier Diode - amzn.to/385tGZE
• SPDT 3 pole Toggle Switch - https://amzn.to/3G5uhHn
• SPST 2 pin 10A Rocker Switch
• Banana Plugs/RCA connectors (Male & Female) - https://amzn.to/3MD8YiU
• DC Jack Connector -
• Deans/XT60 Input Battery Connector
• Alligator clips - https://amzn.to/3yNvAsZ
• DC 12V PC Fan 80mm
• PC Fan Grill
• 18650 Li-Ion 2-Cell Battery Tray - https://amzn.to/3MAhXBb
• Single Socket AC Outlet Connector
• 3-prong AC Input Connector
• 3-Wire AC Power Cord with Compatible Connector
• 14, 20, 32AWG Enameled Stranded Electrical Wire
• Perforated Prototyping boards
• 3M Shortened Philips Head Screws
• Rubber Nobs for PSU Feet (Nerf Dart Heads)
• Plywood Board 4mm
• Sheet Metal 1mm
• PSU Case (x2 CD/DVD ROM Driver Shells)
Step 1: Metalworking - Preparing the Unit's Enclosure Shells
On 2 CD/DVDROM driver shells (salvaged from old PCs) we'll begin by marking out areas where we'd want certain components and parts to stick out. Afterward, we'll cut out these areas with an angle grinder, as well as some shell-adjoining tabs. 33