Introduction: Bench Power Supply
In this instructable I will be showing you how to build a bench power supply using some simple off the shelf components and a custom 3D printed cases. The goal was to make a compact and sleek looking power supply which is powerful enough for most applications.
This is my first project video on my youtube channel so consider giving it a look and subscribing if you are interested in more videos of the kind. This one is pretty simple as my focus was the video making part of it but the videos to come will be more original and involved. So look forward to those.
Youtube Channel: Badar's Workshop
Facebook Page: fb.com/badarsworkshop
Step 1: Parts Required
Step 2: Designing the Case
I designed the case in SolidWorks. Before getting started, I glued some nuts in the housing of the power supply so that I can secure it with the plastic housing. The idea was to make a shell to house everything but not to enclose it entirely so I designed it with an open base.
I made all the measurements using a caliper and designed the case using a simple geometric approach. No fancy curves or anything, just something that is easy to print and ergonomic. That is why I angled the interface at a 45 degree angle to make it easy to see and use.
I paid attention to air flow because under load, the power supply will get warm and I dont want to worry about melting the plastic housing. So I incorporated a fan at the top and a exhaust grill on the side. The bottom has some open area too. The idea is that air will enter from the top and take the heat from the power supply and the module as it exits from the side and bottom.
One more thing to take into consideration while designing is that how will it all go together. Its easy to overlook size of the components while designing because you cant visualize the components. So I had to take account of connectors so that I leave just enough room for easy assembly and disassembly.
Step 3: 3D Printing and Reprinting
I printed the case with an orientation that would give the best surface finish. It took me a couple of tries to get it to print right as the model would detach from the bed while printing. After some trial and error, I figured out the right combination. The trick was to heat the bed just a little bit to 30 C and apply the painters tape on a clean surface.
The first successful print revealed some issues with hole placement for the mounting screws and some size issues. That is usually the case with 3D printed case and I was expecting it to be like so. I made the corrections and reprinted it. Everything seemed to fit right so I went ahead with assembly.
I have attached the stl file and the Solid Works file so feel free to modify it however you like it.
Important Note: I have one extra 3D printed case which I will be giving away to one of you guys who wants to build the power supply. All you have to do is subscribe to my channel and send me a message. I will ship it to the first person who reaches out to me. (US Only)
Step 4: Assembly
The good thing about working with custom 3D printed cases is that if you put thought into the design part of it, assembly can be very simple and satisfying. Just follow the simple steps:
- Secure the banana posts on the front panel using the nuts and washers that come with it.
- Screw in the IEC Jack on the back using M4 screws.
- Pop in the power switch.
- Start the wiring by crimping spade connectors to the appropriate length wires.
- Solder the fan regulator to the output line of the power supply.
- Set the output to 12 V and then solder the fan to the output.
- Screw in the fan using M4 screws and glue in the regulator.
- Finish up the wiring and connect the power supply and power regulator.
- Screw in the power supply using M3 screws and finish up by sticking some rubber feet.
The wiring is pretty simple so I wont go through drawing up a schematic. The AC input of the power supply is connected to the IEC jack through the power switch. The output of the power supply is connected to the input of the power regulator and the fan regulator. The output of the power regulator is connected to the banana jack posts. And the output of the fan regulator is connected to the fan.
Step 5: Testing
The power module is very versatile as you can adjust both, the voltage and the current. It can be used to test circuits and charge batteries among other uses. I tested it running on max load for a few hours and didn't notice any thermal effects.
Step 6: Conclusion
I hope you found this simple project interesting. This project was mainly aimed at getting a start into the video making part of projects as I plan on building a youtube channel.
Let me know what you think in the comments and give me some feedback about my video. I will be making more videos soon.
If you are making a similar power supply and need a 3D printed case, subscribe to my channel and send me a message. I will send it to the first person who reaches out to me. (US Only)
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Please be positive and constructive.
In step 5's picture you are putting your fingers around the cables, since you have to rotate the encoder with your right hand and there are the cables in between. Maybe having them under the display (in the non-45-tilted area) would have been a better choice, wouldn't it?
Hi again bad ars tinkerer , say does your 5 amp model ask for a blocking diode on positive out to prevent back flow from capactive or battery charging ? Mine doe's I just mentally compensate the small difference . Almost perfect device.
Can you use two of these PSU modules and two independent switch mode AC to DC adapters (240v to 30V) to create a dual polarity power supply? (i.e. connecting the negative terminal of PSU A to positive terminal of PSU B to create a common ground)
I think that would be possible. But to be honest I have not yet encountered a need for pos/neg supply other than Cicuits lab. And this wont be the best way to implement such a power supply as you would have to set them up seperately. Not so convenient.
Could this work with a PC power supply?
Well yes an no. My original plan was to use a mini ATX power supply but the module is a step down module. So the voltage range will be capped at 12 volts. Which doesn't really make it very useful. For an ATX power supply, I would recommend using a step-up/down module with a voltage/current meter. I will be doing a build on that soon.
I don’t have a 3D printer can I purchase a printed case from you ? Thanks Gary Demarco Ohio
I have an extra case that I can send to you. Its not the best quality when it comes to 3D printing but it will get the job done. Just message me your mailing address and follow my work on youtube and facebook.