Essential Power Bar - DIY Single PCB design with 3D printed case

[theatrus]

===
Essential Links:

GitHub repo: https://github.com/blueacro/reefvolt-essential-power-bar/
Build guide: https://blueacro.github.io/reefvolt-essential-power-bar/ (Coming Soon)
===

Hi! You may remember me from some other past projects around here (often complicated, supply constrained and pandemic delayed, possibly forever). One thing I needed for a personal aquarium build was a pretty simple power bar for controlling heaters, chillers, and hosting a few simple sensors for the above. I figured, why not make a very simple design, as a single PCB, using nothing but simple through hole parts, as a build-it-yourself design? And then just share it?

This project is designed to not have me as the critical path to building it - you can order the parts from the usual electronics distributors, print (or get printed) the case, and order the PCB from the PCB supplier of your choice from the uploaded Gerber files. Realistically, you should be able to get this built for ~$100 USD, not counting time and the 3d printed case.

For the first post, I will caution I haven't built this yet, so some changes will inevitably crop up. Documentation will be updated as needed. Including pictures in this first post.

A quick look at the concept:

Basic specs:
- 4 outlets (designed for North America, sorry, but maybe can be spun with other connectors)
- 4 heavy-duty relays switching it (Omron G5RL series, 16A rated), with MOV snubbers on the AC side of the relay
- On-board fuse
- On board 12V 20W power supply (Meanwell IRM-20-12)
- On board 5V 5W DC/DC converter (CUI module)
- Mounting positions for either an ESP32 board, or a Raspberry Pi Zero, depending on how you want to control it.
- An on-board loud buzzer for alarming

- On board quick terminal blocks for:
- 2 1Wire temperature sensor channels (for redundancy with failed sensors, second channel will require changes in ReefPi to work)
- I2C connection
- Two float switches or other simple on/off switches
- A header allowing an expansion board to be added


This board is designed for hand soldering assembly using nothing but a basic solder iron, and gives you everything you might need (the essentials), in one controller. Note that I don't intend to offer pre-built boards for this - this is a purely DIY project.

 

[Sisterlimonpot]

Looks good, what processor are you going to use?

 

[theatrus]

Looks good, what processor are you going to use?

The ESP32 full size dev boards (as cloned by many) or a Raspberry Pi Zero. User’s choice. Both pin outs are on the board.

 

[Sral]

The ESP32 full size dev boards (as cloned by many) or a Raspberry Pi Zero. User’s choice. Both pin outs are on the board.

Very nice !

I’m guessing one could also use this as a controllable power bar by only connecting 8 of the PI‘s pins with some cable, like a DB9 ?

Would be a great addition to expose the leftover PI pins as through holes if there is space left.

 

[Sisterlimonpot]

Very nice !

I’m guessing one could also use this as a controllable power bar by only connecting 8 of the PI‘s pins with some cable, like a DB9 ?

Would be a great addition to expose the leftover PI pins as through holes if there is space left.

Isn't that what's on the bottom right of the pcb?

 

[dschuffert]

Nice design. I look forward to seeing the finished project.

 

[theatrus]

Very nice !

I’m guessing one could also use this as a controllable power bar by only connecting 8 of the PI‘s pins with some cable, like a DB9 ?

Would be a great addition to expose the leftover PI pins as through holes if there is space left.

Well, 4 due to there being only 4 outlets .

The relay driver is a simple transistor, you can use it as an external relay power bar from external GPIOs for sure.

As for more pinouts, I added 5 GPIO + I2C on a pin header but can pretty easily route some more out - will do so!. I’m keeping everything intentionally large traces with wide clearance to make sure it can be built on the cheapest PCB process available.

 

[Sisterlimonpot]

I'm happy to see others offering their expertise to help the good of the community! Thank you!

I almost want to build this just for the sake of doing so... if you need help with the case let me know. I'm pretty sure I can take one of the files that are required for pcb manufacturing and transfer it over to solidworks to Boulder off of.

 

[theatrus]

I'm happy to see others offering their expertise to help the good of the community! Thank you!

I almost want to build this just for the sake of doing so... if you need help with the case let me know. I'm pretty sure I can take one of the files that are required for pcb manufacturing and transfer it over to solidworks to Boulder off of.

Always love some thoughts on design aspects.

I uploaded a few of the design files (not finalized yet) including a Parasolid and a DWG:

reefvolt-essential-power-bar/pcb/parasolid_dxf/rv_pwr_es.dwg at main · blueacro/reefvolt-essential-power-bar

DIY Power Bar Design Files. Contribute to blueacro/reefvolt-essential-power-bar development by creating an account on GitHub.

github.com

https://github.com/blueacro/reefvolt-essential-power-bar/raw/main/pcb/parasolid_dxf/rv_pwr_es.x_t

Also initial schematics and BOM in the PDF:

reefvolt-essential-power-bar/pcb/pdf/schematics_bom_assembly.pdf at main · blueacro/reefvolt-essential-power-bar

DIY Power Bar Design Files. Contribute to blueacro/reefvolt-essential-power-bar development by creating an account on GitHub.

github.com

 

[Sisterlimonpot]

Just want to verify. Is the overall dimension of the PCB 8.2" x 4.9" (126.46mm x 208.28mm)

 

[theatrus]

Just want to verify. Is the overall dimension of the PCB 8.2" x 4.9" (126.46mm x 208.28mm)

Yup - I wanted to make sure I was < 220mm or so in the longest dimension to be able to have a hope for an Ender series printer to be able to do a one-part print. I can squeeze things tighter but its already pretty compact around the plugs. And a more square orientation kinda looked weird

 

[Gumbies R Us]

===
Essential Links:

GitHub repo: https://github.com/blueacro/reefvolt-essential-power-bar/
Build guide: https://blueacro.github.io/reefvolt-essential-power-bar/ (Coming Soon)
===

Hi! You may remember me from some other past projects around here (often complicated, supply constrained and pandemic delayed, possibly forever). One thing I needed for a personal aquarium build was a pretty simple power bar for controlling heaters, chillers, and hosting a few simple sensors for the above. I figured, why not make a very simple design, as a single PCB, using nothing but simple through hole parts, as a build-it-yourself design? And then just share it?

This project is designed to not have me as the critical path to building it - you can order the parts from the usual electronics distributors, print (or get printed) the case, and order the PCB from the PCB supplier of your choice from the uploaded Gerber files. Realistically, you should be able to get this built for ~$100 USD, not counting time and the 3d printed case.

For the first post, I will caution I haven't built this yet, so some changes will inevitably crop up. Documentation will be updated as needed. Including pictures in this first post.

A quick look at the concept:

Basic specs:
- 4 outlets (designed for North America, sorry, but maybe can be spun with other connectors)
- 4 extra-heavy-duty relays switching it (Omron G6QE series, 36A rated), with MOV snubbers on the AC side of the relay
- On-board fuse
- On board 12V 20W power supply (Meanwell IRM-20-12)
- On board 5V 5W DC/DC converter (CUI module)
- Mounting positions for either an ESP32 board, or a Raspberry Pi Zero, depending on how you want to control it.
- An on-board loud buzzer for alarming

- On board quick terminal blocks for:
- 2 1Wire temperature sensor channels (for redundancy with failed sensors, second channel will require changes in ReefPi to work)
- I2C connection
- Two float switches or other simple on/off switches
- A header allowing an expansion board to be added

I have yet to design the case, but the PCB is designed to snap into it, but also provide two sections internally - high voltage and low voltage, which will allow you to open the connector side without exposing the mains side. More on this soon.

This board is designed for hand soldering assembly using nothing but a basic solder iron, and gives you everything you might need (the essentials), in one controller. Note that I don't intend to offer pre-built boards for this - this is a purely DIY project.

Stay tuned for the case design, design file upload, and first builds/instructions.

This will be neat once it is fully finished! Pretty awesome right now!

 

[theatrus]

Been experimenting with the case, and in doing so did a few PCB updates:

- Swapped the DC/DC converter for the 5V system to one which can supply 2A, primarily for the Raspberry Pi use case. The good news is the series of converters from CUI are the same rough footprint (different height), so you can put the cheaper converter in if you don't need it. (CUI P78E05-1000 vs CUI P7805-2000-S)
- Added some more large holes in the PCB to support case bosses to secure the lid. Files in GitHub updated.

The concept here is the AC side of the case will have long tall formed-in standoffs on the top-half of the clamshell secured by screws on the bottom, while the DC side will have the opposite with the standoffs formed into the bottom as pictured and screwed into the top (for ease of access to wiring, etc). I realize long tall cylinders aren't the strongest when 3D printing with the bottom of the case on the bed, so will likely have a bit of a snap in feature on the parting line if I can make it happen.

Bottom screws holes are currently designed for a #4 plastic thread forming screw. It could also take heat stake brass inserts into the built in standoffs, but more process. Will test a few things.

 

[theatrus]

Did a few more mounting hole adjustments on the models and did a few test prints to check the PCB features. The case is clearly not done (the walls are just arbitrarily 1" high, for example), but it was enough to order Qty5 of the PCB (cost before shipping, $2.76 each, but required 5).

Example printed in white ASA (about 3hr 40min on a Bambu X1C)

Bottom screw seats are well recessed for these #4 plastic thread forming screws. No supports were required for the tapered hole, which is a win.

I can drive a very long thread forming screw into the tall bosses without any issue (except muscle). The hole size could use some widening. This green example was done in PLA and was an earlier iteration (no strength fillets), about 4hr 10min print time (PLA prints slower).

Once I have the top case designed, the high voltage side will mount roughly like this to the bottom of the case, with the bottom screw driving into the top case boss/standoff. The opposite happens on the logic side, so screws are easily accessible on top. There are two top sections entirely for this reason

 

[Sisterlimonpot]

That looks awesome! I've been extremely occupied with other things, I fully intended on helping with the case but it looks like you got it taken care of. Although those longer screw dowels may need some sort of spline to support them.

Did you see the new petg that is UL rated? Perfect for this situation.

 

[theatrus]

That looks awesome! I've been extremely occupied with other things, I fully intended on helping with the case but it looks like you got it taken care of. Although those longer screw dowels may been some sort of spline to support them.

Did you see the new petg that is UL rated? Perfect for this situation.

I haven’t seen it with PETG but I do have a spool of 94V0 rated ABS from 3dxtech. Haven’t run it through a printer yet.

Also happy to have different ideas on the case front. I’m really not an ME but I’m dangerous enough to work my way around with the extrude tool.

 

[Sisterlimonpot]

Is there a step file of the pcb with all the parts on them?

That would make building a case so much easier for me, and I could justify carving out time to offer my spin on a design.

 

[theatrus]

Is there a step file of the pcb with all the parts on them?

That would make building a case so much easier for me, and I could justify carving out time to offer my spin on a design.

The parasolid (.x_t) has all (most, some models are broken but not critical) of the models which usually imports as an assembly. I can try to build a fused step file as well if it would help.

 

[Sisterlimonpot]

Let me look again, I've always had a hard time navigating github. There's something fundamental that I'm missing to make it all make sense. Hehe

 

[Sisterlimonpot]

How do I download the rv_pwr_es.x_t file?

Honestly, I don't even know how I downloaded the dwg file... it's not intuitive for the way my brain is wired... for sure