Hi Terry, I have a powered USB hub you could borrow if you are still in need of one. It reports to be 3A and was used to power a Pi and some USB bitcoin miners.
No idea if it will back feed a Pi as I powered the Pi from one of the "Fast Charge" USB ports on the hub.
http://www.dlink.com/uk/en/home-solutions/connect/usb/dub-h7-7-port-usb-2-0-hub Regards David On 31/12/16 14:08, Terry Coles wrote:
Hi, I have a request for a loan of an externally powered USB Hub with at least 4 ports. If anyone is in a position to loan me such a device, I'd be happy to collect and return it within a day or so. I'm having a problem with the Wimborne Model Town hardware. I am using one of these with a Pi Zero: https://www.modmypi.com/raspberry-pi/accessories/usb-hubs/hackable-naked-7-port-usb-hub-uk-5v-2.5a/?search=Hac[1] It comes with a 2.5 A supply and is supposed to be able to back-power the Pi. The trouble is that it works when I power-up the Pi with only the mouse and keyboard attached and then attach the other peripherals one by one (three USB Audio Adaptors and a WiFi dongle). It crashes the Pi if I try to boot with said devices all attached. I have run some tests on the PSU brick which comes with this and found that with a 2 Ohm load, I only get 2 A or so and the terminal voltage drops to 4.8 V. We could power the Pi separately, but that adds to the cost and needs a separate mains outlet. However, before I ask for a refund, I'd like to remove this Hub from the equation. I get a similar problem when I use an unpowered hub, but I would expect that, since the WiFi Adaptor takes 240 mA and each of the Audio Adaptors takes another 170 mA (and that's steady state; the inrush current is going to be higher). If I can prove that my peripherals aren't causing the problem, I'd be inclined to go for one of these: https://thepihut.com/products/zero4u-4-port-usb-hub-for-raspberry-pi-zero[2]
-- Next meeting: Bournemouth, Tuesday, 2017-01-03 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:[email protected] / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
