Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!pasteur!helios.ee.lbl.gov!ucsd!ucsdhub!hp-sdd!hp-pcd!hplsla!tomb From: tomb@hplsla.HP.COM (Tom Bruhns) Newsgroups: sci.electronics Subject: Re: Watt Hour Meters Message-ID: <5170068@hplsla.HP.COM> Date: 16 Jan 90 21:41:40 GMT References: Organization: HP Lake Stevens, WA Lines: 18 jgk@osc.COM (Joe Keane) writes: > >A _good_ switching power supply looks like a resistive load, the resistance >slowly changing in response to changes in output current and input voltage. > >---------- Just to continue the basenote drift and give y'all some more food for thought (munch, munch :-) -- two questions (with additional sub- questions :-) : What sort of resistance do you suppose a switching supply looks like? What happens when you hook huge numbers of these up to the power grid? Assume that the switching supply draws a pulse of current synchronized to the line voltage, centered around the peak of the voltage. Thus the current isn't leading or lagging the voltage. What is the power factor? Why?