Live on Kickstarter: Tiny USB 2.5W V/I controllable power supply

[PlainName]

with USB 2.0 we are limited to 500mA @ 5V = 2.5W

Clearly not applicable to V1, but couldn't you use one of the off-the-shelf fast-charge chips to get 1A or more at 5V?

[OwO]

Also in practice most PC USB ports are fine delivering 1-2A, and since you have the current auto-backoff feature, maybe allow drawing up to 2A by default

[Kasper]

Cool idea. Nice job. You mentioned injection molding. Did you look at urethane cast, vacuum forming or off the shelf enclosures?

[electrodacus]

Just made a pledge on the naked version
Take a look at my current Kickstarter https://www.kickstarter.com/projects/electrodacus/solar-bms-and-digital-mppt-for-pv-electricty-and-h  and especially look at how I done the enclosure for my devices as that may be a good solution for your's also.
Your devices looks to be very small so the PCB case should work and cost about as much as the plastic molded one but look better (just my opinion about the look).
Hope your project will be successful but is not looking that great at this point in time.

[Kilrah]

Also in practice most PC USB ports are fine delivering 1-2A, and since you have the current auto-backoff feature, maybe allow drawing up to 2A by default

+1 on that, it's mandatory to default to 500mA max, but there should be "expert" software switches to allow for 1A/2A limits since most ports since years support fast charging.

[brrup]

Many thanks to all my new supporters!

I was thinking a lot about how to increase output current.

In my opinion, USB-BC (USB Battery Charging 1.5A) and USB-PD (up to 100 W) are not that common that it would be okay to increase costs/size for people having it, especially in a first version.

My focus was on USB 3.0 that would allow 900mA but only after the device requests for it. Hope I not overlooked it, but I was not able to find a valid answer how to request 900mA when having a USB 2.0 device, all ends in conclusion that I must have native USB 3.0 support on device then.
Some of the PCs I tested here did active limiting to 500mA when using the USB 3.0 port. It depends on the Host chip, some are more tolerant. It seems to be no problem to shortly get more (I think because mobile USB hard drives need enough initial current to run).

The answer will be USB Type-C, here the concept is nice, they separated USB transmission protocol and power setup mechanism: Up to 15W, there is no need of using USB PD specification, the output current is configured by a simple passive resistor setup for both, the cable and the device. This allows using USB 2.0 together with 15W. When needing more than the 15W again, the USB PD protocol must be implemented.

Yes, I would really like to add this hidden switch to enable more power for people that know what they do, but the final hardware design does not allow this.
I calculated/simulated/tested all for 500mA now, increasing to 900mA or more would be a significant difference and requiring other components.

So sorry, you have to wait for the next version that hopefully will come one day.

Hope your project will be successful but is not looking that great at this point in time.

Your are right, it is not looking that great for the moment. There are too many people on world, that seems not knowing about my project.
Yes, your PCB case style is really cool, never seen this before.
Good luck to you.

Did you look at urethane cast, vacuum forming or off the shelf enclosures?

The truth is, I did not. There are online supplier that are focused on injection molding for smaller prototype quantity. They use aluminum molds that are much better to process automatically. When calculating the total costs for 500 samples, it ends in something between $2 and $5 for small cases. This is still a lot for something that will cost some little cents for larger amounts, but it was okay for me.

[Kasper]

Did you look at urethane cast, vacuum forming or off the shelf enclosures?

The truth is, I did not. There are online supplier that are focused on injection molding for smaller prototype quantity. They use aluminum molds that are much better to process automatically. When calculating the total costs for 500 samples, it ends in something between $2 and $5 for small cases. This is still a lot for something that will cost some little cents for larger amounts, but it was okay for me.

That cost is not too bad then. Based on your funding goal, I figured it was higher.

Finding a small batch method could still help to reduce your goal on the next try. Going the other direction, I was recently told steel molds are better than aluminum if you plan to tune the design because steel molds are easier to weld and cut.  That advice was from my most expensive quoter though so...

Ideally your mech design can be built with any method but at the least it is nice to have 1 small batch method and 1 large batch method.

3DHubs has a lot of info on different materials and processes and will auto quote simple builds which I found really helpful when I started learning about enclosures.

[electrodacus]

Hope your project will be successful but is not looking that great at this point in time.

Your are right, it is not looking that great for the moment. There are too many people on world, that seems not knowing about my project.
Yes, your PCB case style is really cool, never seen this before.
Good luck to you.

Did you look at urethane cast, vacuum forming or off the shelf enclosures?

The truth is, I did not. There are online supplier that are focused on injection molding for smaller prototype quantity. They use aluminum molds that are much better to process automatically. When calculating the total costs for 500 samples, it ends in something between $2 and $5 for small cases. This is still a lot for something that will cost some little cents for larger amounts, but it was okay for me.

For how small your device is and 250 to 500pcs the PCB case may look better (I'm biased about that ) and cost about the same likely around 2 to $3.

[Kilrah]

To me PCB casing looks like an "amateur"/"can't afford more" solution. If he can get an injection moulded plastic case for about same price it's a no-brainer.

Too bad about the higher current capability

In my opinion, USB-BC (USB Battery Charging 1.5A) and USB-PD (up to 100 W) are not that common

All my computers in the past years have suppported USB-BC. It's rarely mentioned but they do. Would imagine the vast majority out there does.

[electrodacus]

To me PCB casing looks like an "amateur"/"can't afford more" solution. If he can get an injection moulded plastic case for about same price it's a no-brainer.

Have you seen my devices made out of PCB ?
I think they look better than what I can do with injection molding and since they are FR4 they are also fire proof. It allows for capacitive touch buttons also at no additional cost.

[brrup]

On of the big players for small batch series injection molding is https://www.protolabs.com/ I think. There you can upload your 3D model, and the next day you get an online offering about the costs.
The big drawback is, if you later want to order e.g. 15.000 parts, the price will be still at > $2 per part.
As I understand aright, the aluminum mold must be replaced by a new one after 15k to 30k samples, but manufacturing is > 50% faster (=lower price). Steel is much hardener, you can produce 100k or more with the same mold.

[grizewald]

It's a shame that this didn't reach the funding goals, but to be honest, I didn't expect it to as the goal was unrealistic.

@brrup: Do you have any plans to still make these, despite the Kickstarter not being funded?

[ANTALIFE]

OP, you should fund this via Crowd Supply. I'm certain you will get more traction there

[brrup]

Now, after more then 2 years, it was possible to finish the project in my spare time!
I have 300 units prefabricated ready for shipping.

The last days, I relaunched the Kickstarter campaign with a funding goal much lower than the first time - so I hope this time it will work!

Here is the new campaign link:

https://www.kickstarter.com/projects/507351807/sirubox-the-v-i-controllable-power-supply-for-your-pocket

[PlainName]

Mine just arrived - thanks!

But... it doesn't work. When I plug it into my PC (W7) I get a popup about the driver being installed, and Windows goes off to Windows Update to find it, but then it exits as nothing applicable being found. Of course, with no driver there is no network and no web page.

Have I missed something, like some specific driver I should manually install? Couldn't find any instructions anywhere, and the website is 'coming soon'.

[PlainName]

Fixed. RNDIS needs to be installed manually, and rather than paraphrase the process here, this is where I found excellent instructions:

https://developer.toradex.com/knowledge-base/how-to-install-microsoft-rndis-driver-for-windows-7

Gosh, it's a long time since I last saw those!

[PlainName]

And having played with it some, it's an excellent piece of kit. Brilliant for shoving in the laptop bag.

A suggestion, though: when the range is being used, the graphs would be better covering only that range rather than the possible fill scale. For instance, when simulating battery power, the range might be set to 2-3V but the graph scale remains 0-15V. It would be much better to show just 2-3V. (Having said that, it's still possible for the voltage to drop below the minimum if current limiting takes place, so perhaps an even better solution would be to scale to the visible min/max values, plus a little for padding.)