Nixies, was Re: Octal

Most UK mains sockets (even at that time) would be the 3 pin 13A rectangular-pin ones. There is no 2-pin plug that fits these, they are polarised. But in the 1950s it would not be that uncommon to find 2 pin mains sockets. No earth, and not polariesed. These came in 2A, 5A, and 15A versions IIRC. There were also 3 pin versions [1] but in wonderful piece of design, the pin spacing was diferent -- 2 pin plugs do not properly fit the 3 pin sockets. [1] The spec mentions a 30A version. I have never seen one, I have never met anyone who's seen one. A friend who works in the electricity supply industry can make the same claim. However, it is a very Bad Thing to assume that neutral is close to ground voltage and safe to touch. It would break a few safety regulations for one thing -- mainly because a defective connection on that side of the cable would make the accessible metalwork live with only the effective resistance of the device to limit the current. That's unlikely to limit the current to a safe (for humans) level. -tony