EEVblog - The Electronics Engineering Video Blog » measurement http://www.eevblog.com No Script, No Fear, All Opinion Thu, 09 Feb 2012 08:56:12 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Copyright © David L. Jones 2011 eevblog@gmail.com (David L. Jones) eevblog@gmail.com (David L. Jones) 1440 http://www.eevblog.com/images/logo/EEVblogDaveLab144x144logo.jpg EEVblog - The Electronics Engineering Video Blog http://www.eevblog.com 144 144 No Script, No Fear, All Opinion David L. Jones David L. Jones eevblog@gmail.com no no EEVblog #215 – Gaussian Resistors http://www.eevblog.com/2011/11/08/eevblog-215-gaussian-resistors/ http://www.eevblog.com/2011/11/08/eevblog-215-gaussian-resistors/#comments Tue, 08 Nov 2011 06:22:55 +0000 EEVblog http://www.eevblog.com/?p=1767

Just how far out is that +/-1% metal film resistor you are using?
Is it just random?
Does it follow the classic bell shaped Gaussian response?
What are the odds of getting one that’s spot on, or right out at the limits?
Dave thought he’d find out, the hard way…

Original Data can be found here, in both Open Office and Excel formats, play around yourself!
http://www.eevblog.com/forum/index.php?action=dlattach;topic=5460.0;attach=16808

See here for more analysis on the data by Bob from Ohio:
http://www.eevblog.com/forum/index.php?topic=5460.msg71085#msg71085

]]> http://www.eevblog.com/2011/11/08/eevblog-215-gaussian-resistors/feed/ 23 0:32:48 Just how far out is that +/-1% metal film resistor you are using? Is it just random? Does it follow the classic bell shaped Gaussian response? What are the odds of getting one that’s spot on, or right out at the limits? Dave thought he[...] Just how far out is that +/-1% metal film resistor you are using? Is it just random? Does it follow the classic bell shaped Gaussian response? What are the odds of getting one that’s spot on, or right out at the limits? Dave thought he’d find out, the hard way… Original Data can be found here, in both Open Office and Excel formats, play around yourself! http://www.eevblog.com/forum/index.php?action=dlattach;topic=5460.0;attach=16808 See here for more analysis on the data by Bob from Ohio: http://www.eevblog.com/forum/index.php?topic=5460.msg71085#msg71085 David L. Jones no no EEVblog #141 – AA Alkaline Battery Capacity Measurement http://www.eevblog.com/2011/01/27/eevblog-141-aa-alkaline-battery-capacity-measurement/ http://www.eevblog.com/2011/01/27/eevblog-141-aa-alkaline-battery-capacity-measurement/#comments Thu, 27 Jan 2011 00:37:03 +0000 EEVblog http://www.eevblog.com/?p=1304

How much Wh capacity does a typical Alkaline AA battery have? Dave intends to find out with his new Gossen Metrawatt Metrahit Energy multimeter

]]> http://www.eevblog.com/2011/01/27/eevblog-141-aa-alkaline-battery-capacity-measurement/feed/ 25 0:19:40 How much Wh capacity does a typical Alkaline AA battery have? Dave intends to find out with his new Gossen Metrawatt Metrahit Energy multimeter How much Wh capacity does a typical Alkaline AA battery have? Dave intends to find out with his new Gossen Metrawatt Metrahit Energy multimeter David L. Jones no no EEVblog #140 – Battery Capacity Tutorial http://www.eevblog.com/2011/01/23/eevblog-140-battery-capacity-tutorial/ http://www.eevblog.com/2011/01/23/eevblog-140-battery-capacity-tutorial/#comments Sat, 22 Jan 2011 22:20:07 +0000 EEVblog http://www.eevblog.com/?p=1301

Ever wanted to know what battery capacity is? Dave takes you through everything you need to know about amp-hours, mAh, watt hours, internal or series resistance, temperature effects, battery cutoff voltages, and characteristic curves.
Part 2 coming soon.

]]> http://www.eevblog.com/2011/01/23/eevblog-140-battery-capacity-tutorial/feed/ 23 0:28:57 Ever wanted to know what battery capacity is? Dave takes you through everything you need to know about amp-hours, mAh, watt hours, internal or series resistance, temperature effects, battery cutoff voltages, and characteristic curves. Part [...] Ever wanted to know what battery capacity is? Dave takes you through everything you need to know about amp-hours, mAh, watt hours, internal or series resistance, temperature effects, battery cutoff voltages, and characteristic curves. Part 2 coming soon. David L. Jones no no EEVblog #133 – Dodgy Digikey Components http://www.eevblog.com/2010/12/14/eevblog-133-dodgy-digikey-components/ http://www.eevblog.com/2010/12/14/eevblog-133-dodgy-digikey-components/#comments Tue, 14 Dec 2010 00:31:46 +0000 EEVblog http://www.eevblog.com/?p=1243

Dave cuts loose on Digikey (or Bourns?) for providing dodgy resistors which made their way into his

]]> http://www.eevblog.com/2010/12/14/eevblog-133-dodgy-digikey-components/feed/ 69 0:17:40 Dave cuts loose on Digikey (or Bourns?) for providing dodgy resistors which made their way into his Dave cuts loose on Digikey (or Bourns?) for providing dodgy resistors which made their way into his David L. Jones no no EEVblog #105 – Electronics Thermal Heatsink Design Tutorial http://www.eevblog.com/2010/08/15/eevblog-105-electronics-thermal-heatsink-design-tutorial/ http://www.eevblog.com/2010/08/15/eevblog-105-electronics-thermal-heatsink-design-tutorial/#comments Sat, 14 Aug 2010 22:44:43 +0000 EEVblog http://www.eevblog.com/?p=986

A follow on from some of the recent blogs that have involved basic thermal heatsink calculation. This time around Dave takes you though the basic theory of thermal design and how heatsink calculations work. Then there are some real world temperature measurements to see how close to the theory we get.

How do you read a heatsink thermal response graph? What is emissivity? It’s all here in thermal design 101.

]]> http://www.eevblog.com/2010/08/15/eevblog-105-electronics-thermal-heatsink-design-tutorial/feed/ 20 0:00:01 A follow on from some of the recent blogs that have involved basic thermal heatsink calculation. This time around Dave takes you though the basic theory of thermal design and how heatsink calculations work. Then there are some real world te[...] A follow on from some of the recent blogs that have involved basic thermal heatsink calculation. This time around Dave takes you though the basic theory of thermal design and how heatsink calculations work. Then there are some real world temperature measurements to see how close to the theory we get. How do you read a heatsink thermal response graph? What is emissivity? It’s all here in thermal design 101. David L. Jones no no EEVblog #86 – Buy a real Analog Oscilloscope PLEASE! http://www.eevblog.com/2010/05/11/eevblog-86-buy-a-real-analog-oscilloscope-please/ http://www.eevblog.com/2010/05/11/eevblog-86-buy-a-real-analog-oscilloscope-please/#comments Tue, 11 May 2010 02:46:02 +0000 EEVblog http://www.eevblog.com/?p=699 Dave is sick of getting emails asking if the cheap toy DSO’s and FPGA/PIC/AVR oscilloscope kits are worth buying.
Guess his response… answers by telepathy please.

]]> http://www.eevblog.com/2010/05/11/eevblog-86-buy-a-real-analog-oscilloscope-please/feed/ 55 0:00:01 Dave is sick of getting emails asking if the cheap toy DSO’s and FPGA/PIC/AVR oscilloscope kits are worth buying. Guess his response… answers by telepathy please. Dave is sick of getting emails asking if the cheap toy DSO’s and FPGA/PIC/AVR oscilloscope kits are worth buying. Guess his response… answers by telepathy please. David L. Jones no no EEVblog #75 – Digital Multimeter Buying Guide http://www.eevblog.com/2010/04/14/eevblog-75-digital-multimeter-buying-guide/ http://www.eevblog.com/2010/04/14/eevblog-75-digital-multimeter-buying-guide/#comments Wed, 14 Apr 2010 11:46:17 +0000 EEVblog http://www.eevblog.com/?p=649 Who else in the industry can give you 52 solid minutes of beginner advice on buying a multimeter?
Dave of course!, who started out wanting to give some “quick” advice, but as usual Dave likes to rant…
So you get a feature-by-feature breakdown on what makes a good digital multimeter. It turns out there is a surprising amount of stuff to talk about on the humble multimeter.

The other video on meter counts & accuracy:
http://www.youtube.com/watch?v=U4JFeU-o2kc

And this is what happens to cheap meters when you overload them:
http://gossenmetrawatt.com/english/seiten/cautiondangerousmultimeters.htm


]]> http://www.eevblog.com/2010/04/14/eevblog-75-digital-multimeter-buying-guide/feed/ 51 0:00:01 Who else in the industry can give you 52 solid minutes of beginner advice on buying a multimeter? Dave of course!, who started out wanting to give some “quick” advice, but as usual Dave likes to rant… So you get a feature-by-featur[...] Who else in the industry can give you 52 solid minutes of beginner advice on buying a multimeter? Dave of course!, who started out wanting to give some “quick” advice, but as usual Dave likes to rant… So you get a feature-by-feature breakdown on what makes a good digital multimeter. It turns out there is a surprising amount of stuff to talk about on the humble multimeter. The other video on meter counts & accuracy: http://www.youtube.com/watch?v=U4JFeU-o2kc And this is what happens to cheap meters when you overload them: http://gossenmetrawatt.com/english/seiten/cautiondangerousmultimeters.htm David L. Jones no no EEVblog #72 – Let’s Design a Product http://www.eevblog.com/2010/04/08/eevblog-72-%e2%80%93-let%e2%80%99s-design-a-product/ http://www.eevblog.com/2010/04/08/eevblog-72-%e2%80%93-let%e2%80%99s-design-a-product/#comments Wed, 07 Apr 2010 21:56:05 +0000 EEVblog http://www.eevblog.com/?p=635 In this supersized lecture length episode, Dave foolishly attempts to explain how to design an example product (the uCurrent) from start to finish.

Read the FULL ARTICLE.
The uCurrent WEB PAGE


]]> http://www.eevblog.com/2010/04/08/eevblog-72-%e2%80%93-let%e2%80%99s-design-a-product/feed/ 20 0:00:01 In this supersized lecture length episode, Dave foolishly attempts to explain how to design an example product (the uCurrent) from start to finish. Read the FULL ARTICLE. The uCurrent WEB PAGE In this supersized lecture length episode, Dave foolishly attempts to explain how to design an example product (the uCurrent) from start to finish. Read the FULL ARTICLE. The uCurrent WEB PAGE David L. Jones no no EEVblog #67 – Hacking the Princeton Tec EOS LED Headlamp with a Cree XPG http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/ http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/#comments Tue, 09 Mar 2010 21:58:07 +0000 EEVblog http://www.eevblog.com/?p=599 Dave does a teardown of the Princeton Tec EOS headlamp and mods it with a new Cree XPG LED.
Throw in a quick reverse engineer of the circuit, gratuitous scope shots, torturing a thermistor, a practical demonstration of why you really do need 5 multimeters on your bench, and as usual Dave finds no problems filling up 25 minutes.


]]> http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/feed/ 42 0:00:01 Dave does a teardown of the Princeton Tec EOS headlamp and mods it with a new Cree XPG LED. Throw in a quick reverse engineer of the circuit, gratuitous scope shots, torturing a thermistor, a practical demonstration of why you really do need 5 multi[...] Dave does a teardown of the Princeton Tec EOS headlamp and mods it with a new Cree XPG LED. Throw in a quick reverse engineer of the circuit, gratuitous scope shots, torturing a thermistor, a practical demonstration of why you really do need 5 multimeters on your bench, and as usual Dave finds no problems filling up 25 minutes. David L. Jones no no EEVblog #50 – Solid State LED Lighting, and How Thermal Design Sucks http://www.eevblog.com/2009/12/19/eevblog-50-solid-state-led-lighting-and-how-thermal-design-sucks/ http://www.eevblog.com/2009/12/19/eevblog-50-solid-state-led-lighting-and-how-thermal-design-sucks/#comments Sat, 19 Dec 2009 05:47:13 +0000 EEVblog http://www.eevblog.com/?p=458 Dave lights up his new backyard deck with Cree XPG LEDs, and then winds up measuring the wind from a storm instead. And who can spell efficacy?

LINKS:
Cree XPG LED Datasheet
Arctic Silver Thermal Adhesive
Luminous Efficacy Graph
Graph #1
Graph #2
LED Strip, Mounted LED
700mA 35W Mains LED driver

]]> http://www.eevblog.com/2009/12/19/eevblog-50-solid-state-led-lighting-and-how-thermal-design-sucks/feed/ 38 0:00:01 Dave lights up his new backyard deck with Cree XPG LEDs, and then winds up measuring the wind from a storm instead. And who can spell efficacy? LINKS: Cree XPG LED Datasheet Arctic Silver Thermal Adhesive Luminous Efficacy Graph Graph #1 Graph #2[...] Dave lights up his new backyard deck with Cree XPG LEDs, and then winds up measuring the wind from a storm instead. And who can spell efficacy? LINKS: Cree XPG LED Datasheet Arctic Silver Thermal Adhesive Luminous Efficacy Graph Graph #1 Graph #2 LED Strip, Mounted LED 700mA 35W Mains LED driver David L. Jones no no EEVblog #48 – Solar Power Hope http://www.eevblog.com/2009/12/04/eevblog-48-solar-power-hope/ http://www.eevblog.com/2009/12/04/eevblog-48-solar-power-hope/#comments Thu, 03 Dec 2009 23:45:44 +0000 EEVblog http://www.eevblog.com/?p=441 Can solar power hope beat out the engineering reality for Dave’s latest project?
Was Doc Brown right?

Solar Cell DATASHEET

]]> http://www.eevblog.com/2009/12/04/eevblog-48-solar-power-hope/feed/ 40 0:00:01 Can solar power hope beat out the engineering reality for Dave’s latest project? Was Doc Brown right? Solar Cell DATASHEET Can solar power hope beat out the engineering reality for Dave’s latest project? Was Doc Brown right? Solar Cell DATASHEET David L. Jones no no EEVblog #38 2of2 – Seismic Survey Boats & Insulation Resistance Measurement http://www.eevblog.com/2009/10/16/eevblog-38-2of2-seismic-survey-boats-insulation-resistance-measurement/ http://www.eevblog.com/2009/10/16/eevblog-38-2of2-seismic-survey-boats-insulation-resistance-measurement/#comments Fri, 16 Oct 2009 11:35:27 +0000 EEVblog http://www.eevblog.com/?p=262 Dave explains errors and problems associated in insulation resistance measurement through a relay test matrix.
Betcha no one else has covered that one before!

]]> http://www.eevblog.com/2009/10/16/eevblog-38-2of2-seismic-survey-boats-insulation-resistance-measurement/feed/ 11 0:00:01 Dave explains errors and problems associated in insulation resistance measurement through a relay test matrix. Betcha no one else has covered that one before! Dave explains errors and problems associated in insulation resistance measurement through a relay test matrix. Betcha no one else has covered that one before! David L. Jones no no