There is also some transformerless power supplies on Discover Circuits website: http://www.discovercircuits.com Great website too! MJ Brush ----- Original Message ----- From: "Charles Craft" To: Sent: Thursday, May 27, 2004 10:06 AM Subject: Re: [EE:] Obtaining 5 Volts from live wire > There's a couple web sites where people reverse engineered the X10 schematics. > > And then lo and behold, they're posted on the Microchip site now! (when did this happen) > http://ww1.microchip.com/downloads/en/AppNotes/00236a.pdf > (pg. 19 - transformerless power supply) > > > Here's the original Microchip whitepaper/tech brief on transformerless supplies: > http://ww1.microchip.com/downloads/en/AppNotes/91008b.pdf > Transformerless Power Supply - TB008 > > A search on "transformerless" at www.microchip.com brought up 5 documents: > > AN236 - X-10 Home Automation Using the PIC16F877A Release Date: 10/30/02 > TB008 - TechBrief Tranformerless Power Supply Release Date: 8/26/97 > DD2016 - Freezer Protector Release Date: 4/22/98 > DD1009 - PIC12C508-Based Timer Release Date: 4/22/98 > DD2009 - Programmable Lights Release Date: 4/22/98 > > > And just for kicks, the Agilent Powerline modem IC data sheet has one on the last page: > http://cp.literature.agilent.com/litweb/pdf/5989-0402EN.pdf > Agilent HCPL-800J PLC Powerline DAA IC > > > > -----Original Message----- > From: William Chops Westfield > Sent: May 27, 2004 1:27 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: [EE:] Obtaining 5 Volts from live wire > > On Wednesday, May 26, 2004, at 18:39 US/Pacific, roines reenig wrote: > > > I think we have drifted a little bit from what I attempted to describe > > initially. > > I was wondering about that. You were mostly interested in how to get > power at (for instance) a lightswitch, when you only have access to the > "hot" side of the connection, and the load, right? > > Most things that do this (ie X10 dimmer switches, or regular dimmers, > for that matter) rely on the load being essentially a slightly > resistive path to the return (a 100W lightbulb has a resistance of only > 130 ohms or so, so it's pretty easy to get 50mA worth of 5V out of > there somehow. > That's why they "only" work on resistive loads. Sneaky, eh? > > BillW > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics