Phil Leigh;586094 Wrote: > Interesting John. > My (modded) DAC already has Schottky's in place and there is a snubber > across the transformer... plus my "mains filter" uses a choke (actually > 2 chokes)... > > Of course the fact that the parts are there doesn't guarantee it all > works properly. > How would you measure the re-injected artifacts? > thx > Phil
The chokes that one sees in PS designs are usually tiny little RF chokes, they are designed to work at MHz ranges. They do nothing at line frequencies. The ones I'm talking about are designed for line frequency (120 or 100Hz). Thats takes a big iron core and a lot of wire. The one speced in this design weighs several pounds and fills up your hand when you try and hold it. The choke is actually bigger than the transformer. For measuring it I take a line voltage to 6V transformer, put a plug (and fuse!) on the primary and a resistive divider on the the secondary. Use a resistance that will draw a few mA, it doesn't need to be a lot. I run this into a spectrum analyzer, but you can send it into a line in of a soundcard and use FFT software. Look at the results when plugged into different sockets, with different boxes plugged in. If using a soundcard it won't have enough bandwidth to see the 150KHz stuff unfortunately but you can still see a lot of the results of the current spikes. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=82648 _______________________________________________ Touch mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/touch
