Copper wire round some form of core. Depends on the design. Could be
ferrite, laminated iron...
Brian

--
From the Bed of Brian Gaff.
The email is valid as
Blind user.
"Fred" wrote in message
...
Hi,

Whilst helping the relatives have a spring-clean, I found an old
exterior light, it is rather like a street lamp, so more
commercial/industrial than domestic. It looks as thought the fitting
is largely made of aluminium, so I was hoping to take it to the scrap
man.

I think they may be sodium lamps as the bulbs look something like a BC
version of this:
http://www.screwfix.com/p/sylvania-h...ges-250w/90688

I notice the description says "golden white" whatever than is! I
thought they were orange.

Inside the fitting is a large (in terms of size, not capacitance)
capacitor and a heavy metal ballast. The ballast is a sealed unit.
Does it have an iron core? Is that why it is so heavy? I'm just
wondering what bag to throw it into to take to the scrap yard. Do I
throw it in with all the steel? Perhaps I should angle grind it open
to see what's inside?

TIA