Re: current limiting choke
>From: "Harri \"Haba\" Suomalainen" <haba-at-cc.hut.fi>
>Subject: Re: current limiting choke
>No wonder! 1.5mm^2 wire will heat to about 70 degr centigrade when you
>put a constant 10A through it. The wire you used has a cross sectional
>area of only some 0.32mm^2! That is for a single wire. For transformers
>etc a good rule of thumb is to head for about 4.5A/mm^2 current density
>in the wire. That is for heading towards constant power handling.
The 0.32mm^2 wire was on the outside layer, I knew what I was doing to
it. It's been rewound back on a spool and larger wire replaced. (It is
much happier now;)
The 4.5A/mm^2 rateing is for confined wire with a 100% duty cycle.
Much smaller wire can be used for "air cooled" or low duty cycle
applications. In this case, I knew that I would be useing it for a
VERY low duty cycle, so I decided to go ahead and wind it rather than
delay untill I could buy some larger wire.
jim BSEE: University of California, Berkeley 1978