Design

Microwave brain scrambler?
Could you use amplitude modulated microwaves to disable a bad guy? Picture this: A robber enters a restaurant, swings a pistol around and demands money. Secreted in the ceiling of the dining room is a microwave transmitter equipped with a parabolic dish that can be aimed to cover any portion of the eating area... 28 Mar 2010 17:53

Low cost PCB's for proto
What is the concensus on the best low cost PCB services for protoyping and small runs of basic double sided boards? There are so many to choose from, in Europe and China, I don't know where to start. Any recommendations? Mark Shriver ... 12 Mar 2010 01:46

Schematic Software Schematic Software
Schematic Software Schematic Software SchematicPro, Custom Design Electrical Schematics Exstensive Parts Library, Import Export Schematics Save in many formats including graphic files http://vehiclerepair.org/schematicpro/schematicpro.htm ... 11 Mar 2010 21:21

Einstein's Biggest Blunder - - Wasn't???
fitz wrote: Einstein's Biggest Blunder Did your mother have any kids that lived? -- Greed is the root of all eBay. ... 10 Mar 2010 22:01

Summing analog signals
Can anyone give me some pointers for mixing DC-20KHz analog signals from different sources? For example, generated noise, sinewaves, etc. I have read about it and tried various circuits, resistor networks, a summing op amp, but it does not appear so straightforward. Adding a signal causes a voltage drop in the su... 12 Mar 2010 12:47

3 phase from func.gen. IC
What would be the simplest way to derive a simultaneous three phase output from a sine wave produced by a single function generator IC ... that does not change as the frequency is varied? Specifically, two additional sinewaves remaining 120 and 240 degrees out of phase with the original as the frequency is varied... 22 Mar 2010 16:50

Durofix RL435
Does anyone have a schematic on the Durofix RL435 emergency lite? I want to look into modifying it for use on 220v. I could just get stepdown transformers (and that ultimately may be the cheapest/easiest fix) but I'd love to be able to just plug these guys in directly. Looks like a switching supply to me. ... 8 Mar 2010 17:33

Variable Square Wave to Sine Wave
Hiya folks. I've been interested in trying to build myself a radio receiver for various bands, primarily as a learning experience. The thing is, though, I've heard that it's kind of hard to build a stable VFO above 50mhz. One of the bands I'd eventually like to receive is 2 meters (144-148mhz). Might be fun to ... 11 Mar 2010 02:23

TL431 stability
The TI data sheet for the TL431 shows two different stability graphs, one for "All TL431 and TL431A devices except for SOT23-3, SC-70 and Q- temp devices" while the other is for "All TL431B, TL432, SOT23-3, SC70 and Q-temp devices". Both graphs are for 25 deg C only. Are these really all the same device, or are ... 10 Mar 2010 01:59

Death & Destruction of a Fluke Multimeter
The title says it all really. See what happens when I try to destroy Fluke's new 28-II Multimeter: http://www.youtube.com/watch?v=qlA7-fh5nDQ Dave. -- --------------------------------------------- Check out my Electronics Engineering Video Blog & Podcast: http://www.eevblog.com ... 10 Mar 2010 07:29