2018-03-10, 09:18 AM
I got a couple of the sealed 3 amp units (Mine says CPT on it) but I haven't had a chance to characterize and test them yet. However I do know that the little LM2596 based open modules that claim to be 3 amps will start crapping out at about 2 amps because they don't have copper ground plane to adequately sink the heat at much over 2 amps and they start crapping out and the output gets really ugly. I have been able to get them to work a bit over 2.5 amps with thermally conductive adhesive and a small heatsink on the bottom side. Before I added the heatsink my windows tablet would slowly discharge even though it is only rated at 2 amps but after it could keep up. It also couldn't keep up with a Raspi 3 with a 5" touchscreen LCD and a webcam that I had on one of my 3D printers.
Also on my Raspis for embedded designs I've been using 20 gauge silicone wire and tacking it directly to the PCB under the USB port and using liquid black tape to insulate it and provide some strain relief. USB power cables are always a crap shoot and even the best only use 22 gauge for the power leads. It also allows me to use a little circuit for foolproof shutdown using a DPDT slide switch, a GP transistor, a relay, diode and a couple of resistors without having to butcher a USB cable
Also on my Raspis for embedded designs I've been using 20 gauge silicone wire and tacking it directly to the PCB under the USB port and using liquid black tape to insulate it and provide some strain relief. USB power cables are always a crap shoot and even the best only use 22 gauge for the power leads. It also allows me to use a little circuit for foolproof shutdown using a DPDT slide switch, a GP transistor, a relay, diode and a couple of resistors without having to butcher a USB cable