Lots of specialized soldering fluxs and fillers out there - Might be worth investigating, or even talking to a welding engineer, if one's handy. ---- Russell McMahon wrote: > I want to be able to make my own custom valued current sense resistors > in lowish volumes - 1's to perhaps 100's. > Requirements are > > - 0.02 ohm to 1 ohm range > - Temperature stable > - Up to 1 Watt dissipation - usually far less. > - Non inductive within reason. > - Reasonably compact. > - Easy and cheap to manufacture. > > If nichrome wire was easily soldered then winding nichrome or other > resistance wire on a high value resistor is an obvious solution. > Nichrome and similar is cheap and readily available and has near-zero > temperature coefficient of resistance. > > However, resistance wire types that I am aware of tend to dislike or > hate being soldered. Other termination means are usually necessary > including welding, spot welding, brazing or crimping. I'll consider > all such ideas but thought that someone may have a bright idea on how > to achieve this. Crimp contacts seem the next easiest solution but > this is not a 'nice' solution. > > I do not want to employ existing commercial resistors, at least at > this stage as > > - Values are custom and may need to be adjusted during prototyping. > > - Suitable wattage, temperature invariant sub 1 ohm resistors tend to > be specialist and expensive compared to other costs in this > application. > > - Temperature invariant resistors are relatively rare. > > - I can control inductance etc as required. > > > These are to be current sense resistors handling currents of up to 5 > amps. Resistor value will vary with current. > > > Thoughts ? > > > Russell > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist