Hey, thanks again, for 0.22 (just to be sure) that would need, by my calculations, 62mm
I assume the inductance of this is a worry though?
Being an LCD bias, it can't be more than a few mA, the data sheet specifies '4mA max', so I guess 6 would be enough to cover it. Thats on the output though, which should probably be about -18V. Rough guess at input current.. 35mA max. so I won't need a big inductor or anything, and I'm sure the wire would do just fine. I have just desoldered a few 0.1R's and 0.01Rs from a old broken motherboard these should do, although I'm completely ignorant when it comes to working out the value for the Rsense (reading the datasheet over and over still).
Cheers for the tips, and sorry for bringing such a basic quesiton to the forums, but you know, thinking 'out loud' (or typing it) helps with the process
Blueteeth
edit: just worked out the Rsense value. I think I'll just use good 'ol trial and error, with a pot on the output to adjust the load. Measuring the voltage output, and adjusting the pot should provide a fairly accurate cut off output current (god bless V=IR). And I'll just keep reducing rsense until its sweet...first SMPS design right here