WARNING Don't Buy ANY USB PD Products Until You See This!

[@g.h.190]

Looks like a nice utility to get a PD capable power supply to shift to higher voltage. If I get it right, chip getting warm 73(8?)L05 is only voltage regulator for PD control chip. Heat in that chip should only depend on input voltage, not current. Heat seen I guess is mostly coming from positive trace at the bottom, that is a bit narrow at input. Traces looks like they go straight from input to output. Voltage dropping at 3A+ at 5V is power supply not able to deliver more.

[@Jueyes-vg2gb]

is PD just power distribution? If so I dont get why people are even saying it, but is that what it means

[@LynxElectronicsLab]

Because a standard usb supply can not provide but the 5v power. So adding the PD lets you know it is one that can provide the higher voltages if requested.

[@LynxElectronicsLab]

Correct the one spot is the 7805 getting hot from the 20v being dropped to 5v. This is why it is not hot on the 5v setting. But the traces heat up also as they and the connector in my opinion is not suitable for high power like the 100 watts the Chinese claim. I might check this, but the supply provides more than 15 watts (3A X 5V) to my soldering iron so I would not expect to fail to provide it to this board. The supply is rated at 65 watts. So I doubt it can only supply 18% of that.

[@Jueyes-vg2gb]

@@LynxElectronicsLab ahh so the power bank I have that has a PD usb-c can suppoedly then provide all these voltages if the device request it, got it.

[@LynxElectronicsLab]

@@Jueyes-vg2gb Yes!

[@timmeh87]

The PD specification says the max current at 5v is 3A so your 65W adaptor is obeying the spec

[@LynxElectronicsLab]

Ok, thanks for that information! That explains it. I’m glad you chimed in with this important information. RJ

[@rrowan327]

Hi RJ, that is so much better board than the previous one. Its crazy what that little board can handle. No active cooling and I don't think I saw a heat sink. On a different subject. I saw on a couple different sites where people are seeing up to 100vac on the tip of the USB soldering irons. There is little to no current so its mostly safe. The problem seems to be grounding which in theory could be an esd static issue. Take care Rick

[@LynxElectronicsLab]

Yeah Rick, they could be useful as a supply for projects you want to power by USB. That’s interesting about the soldering irons. What irons are they seeing this on? RJ

[@rrowan327]

@@LynxElectronicsLab one y-tuber Tony359 said all USB irons since they don't connect to the mains ground. He tested the Kaiweets and Sequre. The kaiweets module looks close to the Fnirsi. There is zero issue if using a power bank. I guess to test yours with a meter connect to earth and the tip of the iron. Power off and power on. Hope that helps Rick

[@LynxElectronicsLab]

Thanks Rick, might take a look at that. RJ

[@Jueyes-vg2gb]

I dont think ill ever truly understand grounding, can they not use like piece of material in a device to use as a ground? Or is it that becuase its not a true ground, sure they can use the piece of material, but the material better be able to disipate the voltage?

[@chasbader]

Power Delivery... Had to look it up.

[@LynxElectronicsLab]

👍

[@davegeorge7094]

what does the pd thing do?

[@darrenmurphy6251]

communicates with the pd compatible wall plug, to tell it to deliver a certain voltage ie, 5v 9v 12v 20v that you set on the dip switches you have that chip or similar in your phone, laptop,tablet ect to do this power delivery negotiation , this board is for if you are making something yourself or adapting something old to use the new universal pd wall adapters ,its just a digital handshake

[@LynxElectronicsLab]

Just as @darrenmurphy said.

[@chasbader]

Power Delivery... Feedback from the charging device back to the charger allows for variation in the amount of power delivered based on the amount required. Much like a voltage sense return line in a classic remote DC power supply, which compensates for the IR loss in the wiring in a chassis.

[@chasbader]

There is this: en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery

[@darrenmurphy6251]

why the heat? its just a digital handshake , it does no voltage convertion for the output just its own supply , suppose if its linear regulation and converting 20v down to 5v or 3.3v for its own chipset but really low current ,a few milliamps but totally irrelavent to load current , just set voltage, what iam i missing??? resistace losses in the pcb traces ?? or does the output current get monitored in the chipset for overload cutout??

[@Jueyes-vg2gb]

dunno but nothing is 100% efficient and you will always have losses and all losses are almost always heat

[@LynxElectronicsLab]

The traces are not able to handle unlimited current as do to resistance they will heat up so there are limits. The hot spot you see is the voltage regulator getting hot when we moved to 20v.

[@Big-hg5zf]

@@LynxElectronicsLab The resistance of the _TRACE_ and the current being drawn by the load soley determine the power drop on the trace, i.e. P=I^2*R. Your IR camera is auto-ranging and the colors are relative to the range it’s displaying. The voltage drop you observe is purely determined by your USB power supply, not the PD device. It’s the USB power supply that is dropping the voltage, not the PD limiting it; there is NO voltage regulator on that specific PD device. 43C is 109F, that’s nothing for the trace or for you in the shower.. Take it to 100C and then it’s something to be concerned about. And you’ve not stated ambient temperature at the time of the test.

[@LynxElectronicsLab]

Do not disagree with anything you are saying. But the supply has demonstrated it can provide more power than I was seeing through the pcb. Based on this I will be redoing this test with more instrumentation to see what the limits I saw were. Look out for a follow up on it soon. I might find a way to get 100 watts into it to see what we get then. RJ

[@timtim8468]

Funny thing about all this, the idea of PD is to use higher voltage to get the amps down. As it's done when it comes to overland lines.

[@uni-byte]

Yeah, these boards are 300% better than the previous ones.

[@LynxElectronicsLab]

No uni, if I am going to use a random percentage I’m going 837%! 🤪 Just got done watching the last load video. Turned out very nice good job 👍 RJ

[@uni-byte]

@@LynxElectronicsLab Thanks RJ.

[@makermatthew]

Does the Kapton tape help with pick and place?

[@LynxElectronicsLab]

Good question, I’m not sure but normally they use kapton tape to protect from heat of the solder and flux vapors. RJ

[@makermatthew]

@@LynxElectronicsLab Indeed, wondered if it also allowed the vacuum pickup of the pick and place machine to hold the part. You sometimes see a small square of kapton tape on usb mini connectors, assuming this is for the same reason 🙂

[@LynxElectronicsLab]

Sounds like a good possibility. That might be it. RJ

[@darrenmurphy6251]

i dont use parts so small that i have to stop breathing when soldering, just so they dont get blown off the board! also find the smaller they are the more likelly to tombstone

[@LynxElectronicsLab]

Exactly! RJ