Power through USB port on MK3
Hello guys. I wanted to know if I can power an LED strip light through the USB port on the MK3. If so what is the recommended load I can put on that port. Thanks in advance
Re: Power through USB port on MK3
The USB port on the printer is a device port, not a host port, as indicated by it being a B style connector - this means it is not required to be able to supply any current by USB specification.
In practice, if it is connected to the printer's 5V rail, it would be limited by the onboard regulator's capabilities minus the parts its driving. This 5V supply on the board can power a Pi Zero W on the back, but in testing not many of the more capable Pi boards, so I'd suspect it can probably supply only an Amp or so in total to external devices, and this is only if the power rail is connected to the USB's power pin (typical designs have the host power the device and the rails to be split, so that the regulators on each device don't fight).
If you have to be taking power off the Einsy board, I'd do it through the headers and not the USB port, but you will be limited to some degree and run the risk of damaging the board if you overdraw. Still better would be taking the 24V from the power supply's line feeding the electronics/heater (since the line feeding the heated bed should use more current). Then your best bet would just be an external supply - they're cheap and easy to get, and you run no risk of overdrawing printer bits and causing issues.