Tired of AC bricks? Try the DCBuddy

[theatrus]

Small design update:

Still working on the base board and the battery backup board, but I made an overall upgrade to move to supporting a 20A load (in the 400W DC range) for a single supply instead of a 200W design. In order to operate at 20A, I've swapped to a 5mm pluggable terminal block, or using the 6 pin MicroFit connector. The DIN4 connector on the Meanwell supplies is limited to around 10A, and a barrel connector even less. There are a number of sealed power supplies that can be used (usually sold as LED drivers) which are bare wire outputs, hence the switch to terminal blocks.

The PCB requires a few more changes (2oz copper everywhere). I also still need to test the board to board connectors and do a little shrinking.

 

[David_CO]

This is a really sweet project. I picked up a hydros kraken a while back and have been wondering why there aren’t more products in this space (without being an EE).

I think a 20A load is probably overkill. Lights and heaters are the only thing that would get you up there on 99% of systems and you need big boy batteries if you want to power those for any reasonable extended period. I opted to get my gas furnace’s f a battery backup and just heat my whole house. Way easier than trying to back up 1200w of tank heaters.

 

[Mark Gray]

Small design update:

Still working on the base board and the battery backup board, but I made an overall upgrade to move to supporting a 20A load (in the 400W DC range) for a single supply instead of a 200W design. In order to operate at 20A, I've swapped to a 5mm pluggable terminal block, or using the 6 pin MicroFit connector. The DIN4 connector on the Meanwell supplies is limited to around 10A, and a barrel connector even less. There are a number of sealed power supplies that can be used (usually sold as LED drivers) which are bare wire outputs, hence the switch to terminal blocks.

The PCB requires a few more changes (2oz copper everywhere). I also still need to test the board to board connectors and do a little shrinking.

Nice I am in the market keep us posted

 

[Reef-Engineer]

This is an awesome project. I am excited to see it as it develops. Powering 5, 12, 24, 36V from a small stack of electronics vice 10 power supplies would be outstanding.

Definitely staying tuned. It might prevent me from executing the power bus solution another user posted a couple pages ago.

 

[yury88]

Small design update:

Still working on the base board and the battery backup board, but I made an overall upgrade to move to supporting a 20A load (in the 400W DC range) for a single supply instead of a 200W design. In order to operate at 20A, I've swapped to a 5mm pluggable terminal block, or using the 6 pin MicroFit connector. The DIN4 connector on the Meanwell supplies is limited to around 10A, and a barrel connector even less. There are a number of sealed power supplies that can be used (usually sold as LED drivers) which are bare wire outputs, hence the switch to terminal blocks.

The PCB requires a few more changes (2oz copper everywhere). I also still need to test the board to board connectors and do a little shrinking.

I'm also thinking to make something like this project, but much simpler(and compact). Just like DC distributor to ports with power measurement and support for backup power + Home Assistant integration.
But why you decide to use this 4-pin connectors for loads?

Look at the CV Kraken controller. Its utilizing GX12-2 ports that can handle 5A+.
Its robust solution, and so far the best that I saw.

 

[theatrus]

I'm also thinking to make something like this project, but much simpler(and compact). Just like DC distributor to ports with power measurement and support for backup power + Home Assistant integration.
But why you decide to use this 4-pin connectors for loads?

Look at the CV Kraken controller. Its utilizing GX12-2 ports that can handle 5A+.
Its robust solution, and so far the best that I saw.

Would love to know your simplification- there already isn’t much here (ideal OR, load switches).

The MicroFit 3.0 connector is both compact, handles 5-8A per pin, and is used by the Neptune 1Link which has some cross compatibility (for example, passing through the CAN-MODBUS signals). It’s also super easy to source and get assemblies made for it.

 

[yury88]

Would love to know your simplification- there already isn’t much here (ideal OR, load switches).

The MicroFit 3.0 connector is both compact, handles 5-8A per pin, and is used by the Neptune 1Link which has some cross compatibility (for example, passing through the CAN-MODBUS signals). It’s also super easy to source and get assemblies made for it.

Oh, sorry, I'm not from North America and am not familiar with the Neptune System. So it can be controlled by Apex directly? Cool.

I want just a box with 8 plugs to distribute power from one large power supply to many loads. With a mosfet switch and current sensor on each load.

And a circuit to switch power to a backup source With esp32 onboard for control.
I can imagine that it can be 1/6 the size of DCBuddy. And with compact size no problem to use separate box for 5, 12, 24V.

Currently, I'm using just relay modules, but it's messy, and I want to organize it.

 

[theatrus]

Oh, sorry, I'm not from North America and am not familiar with the Neptune System. So it can be controlled by Apex directly? Cool.

I want just a box with 8 plugs to distribute power from one large power supply to many loads. With a mosfet switch and current sensor on each load.

And a circuit to switch power to a backup source With esp32 onboard for control.
I can imagine that it can be 1/6 the size of DCBuddy. And with compact size no problem to use separate box for 5, 12, 24V.

Currently, I'm using just relay modules, but it's messy, and I want to organize it.

Sounds good - the original had some wasted space, but ... it's not big. Hard to cram connectors and current monitoring into a useful space. Yes I could have reduced the vertical space here quite a bit, but at some point connectors get so closely packed you can't fit large human hands into the gaps.

No banana for scale, but a metric ruler instead . We can call it banana sized, or really the size of a 120W power brick.

I've been busy doing a few side projects with the ESP32 and the HomeAssistant ecosystem and it's absolutely where I'm leaning with DCBuddy v2. The biggest ESP32 issue is the relatively garbage ADC remains, so multi-channel current sensing needs that outsourced to an ADC or a small STM32 or similar.

 

[yury88]

Sounds good - the original had some wasted space, but ... it's not big. Hard to cram connectors and current monitoring into a useful space. Yes I could have reduced the vertical space here quite a bit, but at some point connectors get so closely packed you can't fit large human hands into the gaps.

No banana for scale, but a metric ruler instead . We can call it banana sized, or really the size of a 120W power brick.

I've been busy doing a few side projects with the ESP32 and the HomeAssistant ecosystem and it's absolutely where I'm leaning with DCBuddy v2. The biggest ESP32 issue is the relatively garbage ADC remains, so multi-channel current sensing needs that outsourced to an ADC or a small STM32 or similar.

Actually, I like this original more. Some space can be saved by getting rid of DC-DC step-down converters.
But later, it will all be used by MOSFETs for each plug....
About adc: 2 pieces of adc1115 will solve the problem.


Actually, I have a question about the scheme with a 2x power source at 24 volts.
What scheme are you using to switch power to the second source?
Because if it's a battery, it can have a higher voltage than a power supply...

 

[theatrus]

Actually, I like this original more. Some space can be saved by getting rid of DC-DC step-down converters.
But later, it will all be used by MOSFETs for each plug....
About adc: 2 pieces of adc1115 will solve the problem.


Actually, I have a question about the scheme with a 2x power source at 24 volts.
What scheme are you using to switch power to the second source?
Because if it's a battery, it can have a higher voltage than a power supply...

No need for a FET, the load controllers on each port already have one, and feature over current shut down. The V2 board is actually smaller - adding the INA28x current amps at each port with the shunt eats space… I’d consider moving to a more expensive load controller with a current output pin just to keep it simple.

This input scheme is two ideal-OR controllers based on an NFET and the LM5050, which was designed for load sharing two adapters or if an adapter gets unplugged, fails, etc. As you said, a battery can easily get to 28 V+ (too high for some equipment that wasn’t designed to run on a battery), and the single FET control can’t turn off an input. If I needed to firmly shut off an input I’d switch to a different controller which handled back to back FETs.

The battery in this case is fronted by a TI BQ25756 which is a bi-directional buck-boost converter. Input/output of 12-60V, battery of 12-60V. Output is regulated by the converter to a programmable value. It also manages charging the LiFePO4. Its designed for USB-PD and PPS power banks, but kinda works fantastic for any general battery backup system. Laying out the test coupon was super quick so I have some enroute.

You plug the power supply into the battery charger (with a reverse blocking diode), and the charger into the DCbuddy. An extra data line signals the DCbuddy it’s lost adapter power and that this input is battery, letting you do load shedding.

The logic is always supplied by standard diode-OR and its own buck regulator.

 

[MikeTheNewbie]

Sounds good - the original had some wasted space, but ... it's not big. Hard to cram connectors and current monitoring into a useful space. Yes I could have reduced the vertical space here quite a bit, but at some point connectors get so closely packed you can't fit large human hands into the gaps.

No banana for scale, but a metric ruler instead . We can call it banana sized, or really the size of a 120W power brick.

I've been busy doing a few side projects with the ESP32 and the HomeAssistant ecosystem and it's absolutely where I'm leaning with DCBuddy v2. The biggest ESP32 issue is the relatively garbage ADC remains, so multi-channel current sensing needs that outsourced to an ADC or a small STM32 or similar.

This project looks awesome. Have you considered looking into Neptune's EB832 CAN signal and making this behave as a DC version of it? I've always been curious about the communication between Apex and its accessories but never tried analyzing it.

 

[theatrus]

This project looks awesome. Have you considered looking into Neptune's EB832 CAN signal and making this behave as a DC version of it? I've always been curious about the communication between Apex and its accessories but never tried analyzing it.

It’s possible, and will reserve that feature for later.

On the simplified DC Buddy front I’ve made a bunch of updates for manufacturing (part availability and stock and price) and swapped around a lot of parts. The good news is we now have both:
- Per port current measurement with up to 5A per port.
- WiFi control via Home Assistant. Embedded ESP32 running easy to modify ESPHome firmware.

For sake of simplicity I’m going to roll a single input, 8x output, 12-36V version first. Dual input and stackable versions to follow.

 

[MikeTheNewbie]

It’s possible, and will reserve that feature for later.

On the simplified DC Buddy front I’ve made a bunch of updates for manufacturing (part availability and stock and price) and swapped around a lot of parts. The good news is we now have both:
- Per port current measurement with up to 5A per port.
- WiFi control via Home Assistant. Embedded ESP32 running easy to modify ESPHome firmware.

For sake of simplicity I’m going to roll a single input, 8x output, 12-36V version first. Dual input and stackable versions to follow.

After trying to read CAN over the aquabus cable all morning, I realized it doesn't use the CAN protocol. The I saw an old post stating it uses CAN transceivers (link layer) but not the protocol

 

[theatrus]

After trying to read CAN over the aquabus cable all morning, I realized it doesn't use the CAN protocol. The I saw an old post stating it uses CAN transceivers (link layer) but not the protocol

Correct. It uses a proprietary layer built on top of FreeModbus. There are a number of handshake steps you need to perform, but there is code available to emulate some modules. Fully emulating the EB832 with per port power is trickier.

 

[theatrus]

Starting to polish! I owe people an FAQ, but I'm happy with where this ended up:

Key changes:
- Open Hardware design.
- 12V to 36V design. All ports share the same voltage, but you can pick the adapter voltage of your choice.
- No longer dual adapter input. If you want backup, this can be done, but it's now external (coming soon!)
- Ditched the stacking connectors and using a Micro-Fit 3.0 as a module connector for both battery input and attaching other adapters.
- Now ESP32 (C3) powered. USB-C programming port. OTA capability. Planning on releasing an ESPHome firmware configuration due to its sheer simplicity and ease of customization, and dead-drop simple tie in into Home Assistant.
- Now with per-port current monitoring, up to 5A per port.
- Output connector is now a 2.1x5.5mm jack, using a male to male power cable. Why? Simply, cable availability that's inexpensive. No need for custom cables (that I'd have to get made...), when you can buy something on Amazon or other market places.
- Still three types of power input (2.1x5.5mm, DIN4 for Meanwell OWA adapters, Micro-Fit 3.0 6 pin)
- Micro-Fit connector uses off the shelf cables from Molex.
- Micro-Fit connector carries a CAN bus signal allowing reliable signaling from the upcoming battery backup system.
- 5mm LEDs on all ports and two status LEDs, which shine through the top case nicely like this: https://www.reef2reef.com/threads/e...ign-with-3d-printed-case.999511/post-12454877


Design files are starting to be posted to:

GitHub - blueacro/reefvolt-dcbuddy: Various DC power accessories for the aquarium market

Various DC power accessories for the aquarium market - blueacro/reefvolt-dcbuddy

github.com

Manufacturing status:
- Most of the ICs have already been purchased.
- Planning an initial prototype run of boards (~5) this week after I've checked off a few more things.

Case status:
- Not started design yet. Soon.

 

[theatrus]

Initial batch (5) of PCBs ordered! Mostly assembled, minus the LEDs and two of the connectors which are hand solder parts right now. Exciting stuff.

I did make some... upgrades.

Mostly the display, because they're cheap and doesn't change anything on the board except for a header and some holes.

There is a buzzer as well.

I started some of the case layout. Very much in progress!