Posted by daestrom on June 22, 2010, 10:16 pm
Which is why I think the Navy (submarines) used circles and bars. A bar
lit up meant the valve was shut, and a circle was open.
On drawings, sometimes a 'filled in' valve symbol means normally shut
and a hollow one normally open.
Then add on to that air-operated valves where a filled in symbol for the
operator meant air pressure to open the valve and a hollow one meant air
pressure to shut the valve. (I think).
Posted by danny burstein on June 22, 2010, 10:22 pm
Meanwhile, the European standard for electricl switches
usese a circle (as in a zero) to indicate that
the switch is open - meaning no current, and
a line to indicate that current is going through...
Knowledge may be power, but communications is the key
[to foil spammers, my address has been double rot-13 encoded]
Posted by vaughn on June 22, 2010, 10:42 pm
In the world of the electronics technician, black is traditionally negative,
which is typically ground. After being an electronics tech for about ten years,
I moved into the traffic signal biz, which runs by electrician's rules. In the
electrician's world, black is always hot. I made some spectacular fireworks
before I got that straight in my head!
Posted by Jim Wilkins on June 23, 2010, 12:37 am
For one low-budget electric vehicle project the only wire they had
that was flexible enough and met gauge, voltage and temperature specs
was bright orange, so I wired everything with it, both sides of the
battery pack, controller and motor. I taped the ends at first but that
got lost during artsy chassis modifications. I kinda hope I never see
that thing again.
Posted by RamRod Sword of Baal on June 20, 2010, 4:50 pm
Neutrals are always needed as the power flows from the active wire through
the appliance and back through the neutral (over simplification).
I actually live is Australia, but did live in the UK for a while quite a few
years ago so I am not 100% up to date on how things are wired there.
So I can only with any accuracy talk about how things are wired in
We use a system called MEN, that is Mains Earth Neutral, or Multiply Earth
Neutral, this means that the earth wire and the neutral wires are connected
together in the switchboard of each house.