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EEVblog #612 – Mailbag

Mailbag Monday What should Dave do with his new lab internet bandwidth? Thermocouple Tutorial Arduino Tape Shield Arduino Thermocouple Shield MAX31855 Boldport PCBmodE Artistic PCB layout program System MERA-400 computer schematic Elecktronika MK-61 Russian Calculator Forum HERE Podcast: Download

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EEVblog Lab Shelving Upgrade Continues

The EEVblog lab continues to get upgraded. Some more shelving installed in the office cubicle. Another lot to go in the main area, and a new island bench to come as well. Still have 3.7m of ESD matting left over from that 10m roll. They fitted just perfectly in the …

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EEVblog #611 – Electret Microphone Design

Part 5 – Doug Ford explains the design of Electret Microphone circuits, and all the associated traps: Transconductance, correct biasing, and temperature effects, leaky JFETS, non-linear clipping & headroom, current noise and voltage noise, and pseudo bias resistors. Also, the non-intuitive concept of higher resistance = less noise, and how …

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Announcement – Hack A Day Prize – WIN a trip to SPACE!

Hack A Day are running the biggest electronics hardware design contest ever. The winner gets to fulfill every nerds fantasy, a trip to space! Dave is going to be one of the judges, so start sucking up now… The contest is to design an “open connected device”. So basically anything …

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EEVblog #610 – Why Digital Scopes Appear Noisy – Part 2

Why do digital oscilloscopes appear noisier than traditional analog oscilloscopes? PART 2 Learn how and why your digital storage oscilloscope display the noise that it does. In this 2nd installment Dave shows how waveform update rate affects the apparent displayed noise of a waveform, and alters the waveform update rate …

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EEVblog #609 – Condenser Microphone Design Tutorial

Part 4 of microphone technology with Doug Ford, former head designer at Rode Microphones. In this video Doug discusses how to design a condenser microphone, in particular the Rode Classic II microphone. Many things discussed include: External polarisation voltage generation and the relationship with sound pressure. The trade-offs involved in …

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EEVblog #607 – Agilent B2912A Source Measure Unit SMU Teardown

What’s inside a $13K Agilent Source Measure Unit capable of 15fA and 100nV resolution? Plus triaxial cables, and low current measurement connection. Data Sheet Connection Guide Component Datasheets: FDS8978 Dual MOSFET OPA1611 Audio Opamp ISO7240A Isolators ADS8202 Diff Amp ADS1675 24bit ADC 30N06 MOSFET Forum HERE High Resolution Teardown Photos: …

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EEVblog #606 – Mailbag

Dave flips the bird. A 1970’s Mattel car racing game. Sex on a stick multimeter probes. Sagan, Mrs EEVblog, and a whole lot more in today’s Mailbag Monday Bob Widlar poster Easy EDA Channel Engineer on Youtube We Make Things http://felitek.de/ http://www.probemaster.com/ Forum HERE Podcast: Download

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EEVblog #605 – Fig.8 & Cardioid Microphone Patterns

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. …

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EEVblog Server Issues

The EEVblog dedicated server which hosts this site and the forum went down for most of today. It was not a fault of the server itself, but a major outage for all dedicated servers hosted with HostGater, the company I use that provides the server. Here is some info Sorry …

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EEVblog #603 – Gas Sensor Teardown – Dräger Multiwarn II

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. …

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EEVblog #602 – Introduction to Microphones

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. …

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