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] 

-- 



                Terry Coles

--------
[1] 
https://www.modmypi.com/raspberry-pi/accessories/usb-hubs/hackable-naked-7-port-usb-hub-uk-5v-2.5a/?search=Hac
[2] https://thepihut.com/products/zero4u-4-port-usb-hub-for-raspberry-pi-zero
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