Engineering and technology notes

Raspberry Pi • View topic – Power for an external HDD

Jovan Stosic February 24, 2017

I have the Raspberry Pi Model B with its original power adapter (1A). If I connect a USB external drive to it, the drive tries to start spinning but it won’t, and the Raspberry Pi does not detect it. If I connect it using a Y USB cable (1 USB for data + power and the second USB only for power), the Raspberry Pi restarts and the drive does not start spinning anyway. If I use the Y USB cable, but connect the data + power to the Raspberry Pi and the second USB (power only) to an external USB adapter (from a

Source: Raspberry Pi • View topic – Power for an external HDD

John William Strutt, 3rd Baron Rayleigh

Jovan Stosic February 23, 2017

John William Strutt, 3rd Baron Rayleigh OM PRS (/ˈreɪli/; 12 November 1842 – 30 June 1919) was a physicist who, with William Ramsay, discovered argon, an achievement for which he earned the Nobel Prize for Physics in 1904. He also discovered the phenomenon now called Rayleigh scattering, which can be used to explain why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves. Rayleigh’s textbook, The Theory of Sound, is still referred to by acoustic engineers today.

Source: John William Strutt, 3rd Baron Rayleigh – Wikipedia