Full Power Magnetic Charging Card

That’s so awesome and looks great @Moe_Wigs! Thanks for the upload, I’ll check it. I also just order the board as well :smile:

just ordered. cant wait to try it out when they arrive in a month

which case design do you recommend? i could print ahead of time while i wait for the usb adapter

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ok cool ill give the 2nd redesign a shot first and see how that goes. estimated arrival for the board is june 14 so i got some time to mess around with prints

Looks awesome! Now I am super excited for mine to arrive :slight_smile:
I went with some PTEG for the print, but it came out a bit stringy, might give it a shot with PLA as well, or just tweak some settings.

At the start of this discussion there is a link to “Magnetic USB-C Cables are not recommended”
I noticed in a thread that the motherboard has “ESD protection diodes” fitted to protect from static electricity damage to the board, am I correct in assuming that the warning about using a magnetic coupler is negated by the diodes?

Unless there are specifically protection measures on the USB-c ports on the motherboard - I wouldn’t rely on it. @Kieran_Levin said that the protection diode was on a battery connector signal. Perhaps there’s room for a magnetic charging card similar to what people are building with appropriate protection circuitry built into the expansion card?


Thanks for the clarity I suppose this is a question for framework support. :grin:

No, not really. Every good USB device has protection diodes, but they can only do so much. There are also different kinds of protection diodes, the power lines have relatively beefy ones, as they’re the connections which you can touch or which are inserted first on a normal USB connector

The data lines, especially the USB-3.0 super speed lines only have very flimsy protection diodes, as using the bigger ones degrades the signal too much. Which is the reason the high speed connections are very far inside the standard USB connectors where you normally can’t touch them.

If I were to design such a magnetic card, the prototypes by @Moe_Wigs look great, but I’d use a custom PCB instead where the super speed lines simply wouldn’t be connected. And then I’d probably add some more high quality protection diodes, just to be safe.

Would still likely violate the USB specs, though, but at least I’d feel much safer.


Thanks Jonathan_Haas for the clear and concise explanation, I definitely will not be using a magnetic coupler now that I fully understand the risk.

Then you could only charge the laptop and would have no data transfer. I think you’d need to keep the CC lines connected for power delivery to work.

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The protection diodes should probably go between VCC and GND (so they short-circuit excess voltage).

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Yes, I’ve updated the diagram.

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got my usb part in and printed the case last night. i went with the redesign 2. i had to cut off the over hang at the opening cause the usb was just a little too long. and i did have to cut the shoulders off the usb so it would fit. the original redesign would prob be the perfect one for me to print which i may try later in the week. but overall i think it came out great!



That’s great to hear. Glad it worked out for you.

@John_R_Conti I think I might have run into the same issue as you. My board just arrived and looks like the build is slightly different from @Moe_Wigs. I am going to attempt to shorten up the side that would connect to the framework to see if there is a better fit.

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Anything specific I should do? I was just going to snip them off with a small needlenose

Are the shoulders functional in that they hold the port in any way. If so couldn’t the card be amended to allow them to indent the housing?

@Moe_Wigs Do you what printing settings I should use when printing the ExpansionCard mag charge second redesign?

@Ramon_Gonzalez i just cut mine off not thinking of any consequences. no problems so far

@Nathan3 every printer is different. you need to do what works best for you. but i changed my nozzle to .2 and did a layer height of .12 for extra detail. infill 5%. speed 60. supports everywhere