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