Design

Low cost anemometer, I need some help
> How are you going to calibrate it? Hold it out the car window in a windless day. Travel at 20mph in both directions. ;-) Dave ... 23 Jul 2010 16:56

ZigBee and alternatives - low power radio links
I'm looking for an inexpensive way to poll a device from about 200 feet outdoor, line of sight. USA-only, no FCC license needed, etc... We need to exchange about 50 characters or so back in forth, a couple times in a session. Data timing is NOT critical. If more than one device is present, we need to know that... 25 Jul 2010 09:44

Baxandall class D oscillator, can it produce a triangle likewaveform?
John Fields a �crit : On Fri, 23 Jul 2010 08:53:46 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: On Thu, 22 Jul 2010 15:04:46 +0100, "markp" <map.nospam(a)f2s.com> wrote: Hi All, If I had a Baxandall class D resonant oscillator, would it be possible by m... 24 Jul 2010 12:19

The effect of the price of copper on the thickness of TO220 packages
My old 7805 stabilisrs have 1.3 mm thick copper. The new ones I bought today are .5 mm. The new ones you can just bent with plyers, even break the tab off. Wonder when we go to .25 :-) ... 25 Jul 2010 15:07

Relay Question
I need a way to test if there is current in the Service BEFORE it reaches the Main Disconnect. I could put a relay coil across it, but I need a better, safer more reliable way. Does anyone know? http://jons-math.bravehost.com/transfer.html ... 28 Jul 2010 21:46

StereoZoom 4 Focus Knob Repair
Anyone know of a mechanical/service reference for the B&L StereoZoom 4 focus focus assembly? In my infinite wisdom, I disassembled mine to clean /repaint and now cannot get it back together so that it operates smoothly.. I've found little internet information on the actual mechanical workings of this assy, o... 24 Jul 2010 10:10

component name id prefixes
Hello everyone. We're just starting to use a new CAD system which means that we can standardise on PCB component id prefixes. At the moment engineers use what they feel like, although if I tried using U1 instead of IC1 there would be a revolt in our CAD dept. Somewhere there is an IPC (I think) standard for th... 31 Jul 2010 13:59

Totally O/T: what was that system called?
Back in the early 90's I read about an artillery radar system called "red......". In operation it detected an incoming round, computed the trajectory and source coords, and then controlled the local artillery to return fire at the source before the incoming round had arrived. Anyone here recall what it was calle... 25 Jul 2010 04:25

AC to DC conversion without using diodes and no external supply
Hi, Firstly the reason I have the constraints of not using diodes is that the AC input voltage is very low (200mV) and even low voltage Schottkey diodes have a forward drop of (230mV). And regarding external power supply, this circuit is aimed at energy harvesting, so the aim is to do everything with only the... 26 Jul 2010 12:44

ADC techniques, was Re: Diode-Connected Transistors
On Thu, 22 Jul 2010 06:57:55 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: On Thu, 22 Jul 2010 15:14:13 +1000, Grant <omg(a)grrr.id.au> wrote: On Wed, 21 Jul 2010 20:33:03 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> wrote: On Wed, 21 Jul 2010 19:59:24... 22 Jul 2010 18:02