Doug Ford, former head designer from Rode Microphones continues with Part 2 of the microphone technology series by explaining the construction of noise cancelling Figure 8, cardioid, and hyper cardioid microphones. Also, how the polar patterns and responses relate to the physical construction, and how the frequency response is affected.
Proximity boost effect,
Microphone calibration is also discussed using a home made artificial voice speaker box.
And practical considerations about foldback wedges used in stage performances and how to avoid feedback using proper microphone technique.
EEVblog #605 – Fig.8 & Cardioid Microphone Patterns - [Link]
This video describes the basic concept behind eye patterns on an oscilloscope and how they can be used to evaluate the quality and signal integrity of a serial bit stream or data stream. It discusses how signal impairments such as jitter, ringing, overshoot, undershoot, noise, etc. can all be evaluated on a serial bit stream using an eye pattern.
What is an Eye Pattern on an Oscilloscope - [Link]
H-Bridge Motor Speed Controller Tutorial - [Link]
This is a review / buyer’s guide / tutorial on the Rigol DS2000 / DS2072A. As this is my first oscilloscope review I’ve gone into a little more detail for those new to oscilloscopes. I’m trying to use a standard set tests for this review which will carry through to future reviews so comparisons can be made between oscilloscopes.
I will do a side by side review of the Rigol DS2000 vs the Agilent DSOX2000 in the future. In this review I do make comparisons and references to the Agilent 2000 X series.
Review: Rigol DS2000 Oscilloscope - [Link]
What’s inside a Dräger Multiwarn II gas detection warning system used in mining, oil, chemical, and emergency services etc to detect hazardous or explosive atmospheres.
Intrinsic safety design and how both catalytic bead and infrared IR gas detectors work, and pellistors. And a teardown of a Hydrogen Sulfide (H2S) sensor.
EEVblog #603 – Gas Sensor Teardown – Dräger Multiwarn II - [Link]
Ray Wang @ youtube.com writes:
This is Part 2 of the NeoDen Tm-240A pick and place machine demo. This time I am using it for a production run to assemble the OpenSprinkler Pi circuit board. Details can be found in this blog post: http://rayshobby.net/?p=6688
NeoDen TM-240A Automatic Pick and Place Machine Demo - [Link]
In the first of a series of videos tutorials on microphones, Doug Ford, former head designer at Rode Microphones explains the basics of how microphones work, the different types – carbon, dynamic, ribbon, condensor/electret, and how the omnidirectional pattern works. Also, the internal construction of a high end measurement microphone.
EEVblog #602 – Introduction to Microphones - [Link]
Why do digital oscilloscopes appear noisier than traditional analog oscilloscopes?
Dave busts the myth that digital scopes are noiser than analog scopes, and demonstrates what inherent advantages digital scopes can have over analog scopes in terms of true waveform capture. And also why your analog scope may be hiding important signal detail from you.
Demonstrations of how memory depth, analog bandwidth, averaging, and intensity graded displays can all effect the signal detail you see on your digital oscilloscope.
And how long exposure camera shots on analog oscilloscopes can reveal detail you can’t see with your eyes.
EEVblog #601 – Why Digital Oscilloscopes Appear Noisy - [Link]
Build this homemade “one-size-fits-most” speed controller for use with your hobby projects. It’s small, it’s flexible, and it’s built with off-the-shelf components around the venerable 555 timer IC.
Dial-a-Speed Motor Controller - [Link]