Path: utzoo!attcan!uunet!samsung!usc!srhqla!quad1!psivax!torkil From: torkil@psivax.UUCP (Torkil Hammer) Newsgroups: sci.electronics Subject: Re: Fluorescent light ballasts Message-ID: <2956@psivax.UUCP> Date: 24 Nov 89 23:51:26 GMT References: <22334@gryphon.COM> <4995@ae.sei.cmu.edu> <7835@ttidca.TTI.COM> <5068@ae.sei.cmu.edu> Reply-To: torkil@psivax.UUCP (Torkil Hammer) Organization: Pacesetter Systems Inc., Sylmar, CA Lines: 15 In article <5068@ae.sei.cmu.edu> rsd@sei.cmu.edu (Richard S D'Ippolito) writes: # #with two 40w tubes, fixture, cord and ballast. The ballast nameplate reads #"120V 60Hz .85A", UL, minimun starting temperature 50 deg. F." # #More enterprising folks might be able to calculate the power factor. We can't do so without knowing the efficiency factor, aka cosine of phase angle, which is measured as the ratio between watts and voltamperes. Questions: 1. Why is there a minimum starting temp for the ballast? 2. Do today's ballasts come with a capacitor or other phase compensation to optimize the irregular, but predictable, current pattern of flourescent tubes? Brought to you by Super Global Mega Corp .com