6 Sep
2014
6 Sep
'14
7:16 a.m.
Bob, does your mass budget allow you to include a fuse in series with the burn resistor?
eg Looking at: http://www.matronic.de/pdf/herstellerkataloge/littelfuse_katalog/Chapter10Su...
Your 15R burn resistor will draw ~ 0.5A from your 7.5V supply? Looking at the fuse curves for the "FLAT-PAK Slo-Blo Fuse 203 Series" on page 23 of that PDF, the 1/4A variant of those fuses should open after about 6 seconds @ 0.5A (might blow a bit quicker in a vacuum though since there is no atmosphere to convect heat away from the fuse?)
There will be other suitable fuses - the above is just an example (I do not work for Littelfuse).
73 ZL2WRW Ross Whenmouth