- Blog entry posted in 'Lab equipment', July 18, 2014.
So, issue i'we been having with my isolation transformer is huge inrush peak during startup. around 400A current pops fuse every now and then, so i decided to desgin inrush current limiter. of course this costs more than fuses, but in long run it's worth it. the idea is simple: timer controls bigger 10A relay, which in turn shorts current limiter resistor that is in series with transformer. Works like charm!. of course, one possible flaw is that if relay's contacts are stuck close, limiter doesn't work as intended, but doesnt affect satefy. there are couple ways to go around it, but relays are long-life after all.
current limiter is now just 60w bulb, but i'we ordered 1k/100w resitor to take it's place.