Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!rphroy!caen!uwm.edu!linac!att!pacbell.com!lll-winken!telecom-request From: uccxmgm@unx2.ucc.okstate.edu Newsgroups: comp.dcom.telecom Subject: How Many Walkmansz? Message-ID: Date: 28 Mar 91 06:32:52 GMT Sender: Telecom@eecs.nwu.edu Organization: TELECOM Digest Lines: 21 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 247, Message 5 of 6 While a 9-volt 500A supply is a pretty big beast, it wouldn't really be that difficult to come up with that kind of voltage. If you have a 12-volt center-tapped transformer, you will get 6 volts RMS each side of center. If rectifier diodes are connected back-to-back and their other ends connected to the two outside ends of the center tap, you have a center-tapped full-wave rectifier configuration. If you now put a capacitor between the center tap lead and the junction of the diodes, you have a filtered full-wave DC supply. This voltage will be 1.414 or the square root of two times the RMS voltage. For a 6-volt RMS output, this means that your DC will be at the peak voltage or 6*1.414 or close to 9 volts. Such an arrangement has some 120hz ripple in it, but it's close enough for government work. I wonder if they used electrolitic rectifiers back then to handle that kind of current? Martin McCormick Oklahoma State University Computer Center Stillwater, OK WB5AGZ