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29 Aug 2014

## Build a 2.5V to 14V 3A adjustable power supply!

A tutorial on feedback resistors in DC-DC converters and how to build a high current adjustable power supply using an LM2678.

29 Aug 2014

## Flir One teardown

A look inside Flir’s thermal imaging add-on.

29 Aug 2014

## EEVblog #656 – Pacemaker Monitor Teardown

What’s inside a dial-in pacemaker monitor system?

EEVblog #656 – Pacemaker Monitor Teardown – [Link]

23 Aug 2014

## DC Power and Energy Measurement Meters – Pt 1

by mjlorton:

In this series of video I want to take a look at what the industry has to offer in terms of DC Power and Energy Measurement Meters / Analyzers (Analysers). There seems to be a distinct lack of affordable instrumentation in this area.

DC Power and Energy Measurement Meters – Pt 1 – [Link]

18 Aug 2014

## How a Diode Ring Mixer works | Mixer operation theory and measurement

This video describes how a classic double-balanced diode-ring mixer operates. Very basic mixer theory is quickly reviewed, which describes how the sum and difference of the LO (local oscillator) and RF (Radio Frequency) inputs are generated at the IF (intermediate frequency) output. It is also noted that the sum and differences of the harmonics of the LO and RF are also present at the IF output. Math waveforms on the oscilloscope are used to illustrate the operation of the mixer, and the actual waveforms from the mixer are compared to the math waveforms and the differences are discussed. A detailed description of the operation of the mixer is presented, including the switching action of the diodes. Finally, the frequency components are are expected from the mixer are shown on the spectrum analyzer.

How a Diode Ring Mixer works | Mixer operation theory and measurement – [Link]

18 Aug 2014

## EEVblog #652 – Oscilloscope & Function Generator Measurement Trap

Dave explains a big trap in high frequency measurement with your oscilloscope. Based on a viewer request, Dave demonstrates how to incorrectly and then correctly measure the signal output level over frequency of your function generator using your oscilloscope. Some whiteboard transmission line theory is thrown in as well.

EEVblog #652 – Oscilloscope & Function Generator Measurement Trap – [Link]

13 Aug 2014

## Theory, Design and Characterization of Delta-Sigma Analog to Digital Converters

TheSignalPathBlog writes:

In this episode Shahriar explores the world of Delta-Sigma modulators with emphasis on a Delta-Sigma Analog to Digital Converter (ADC). The basic concepts of analog to digital conversion is presented, particularly with respect to quantization noise spectral shape and power density. Next, oversampling ADCs are presented to demonstrate the possibility of increasing SQNR (ENOB) through manipulation of quantization noise spectrum.

Due to the practical limitations of high oversampling ratios, delta-sigma modulations is explored. The principle operation behind delta-sigma ADCs is presented with detailed explanation on noise shaping, filtering and decimation. The signal and noise transfer functions for a 1st order and 2nd order delta-sigma ADC are derived. Finally, as a practical example, a 2nd order delta-sigma ADC based on a 1-bit quantizer is presented. The ADC uses two Miller integrator op-amps, one comparator and a D-Type flip-flop. The complete measurement of this delta-sigma ADC is presented. The impact of over sampling ration, op-amp linearity and input signal bandwidth is presented. The slides for this video can be downloaded from The Signal Path website.

Theory, Design and Characterization of Delta-Sigma Analog to Digital Converters – [Link]

4 Aug 2014

## Video Series – Touring Factories in Shenzhen

by limpkin @ limpkin.fr:

During the month of July I was visiting Beijing and had an extra 10 days to spare. What to do? Well it took me less than a few minutes to decide to go the wonderful city that is Shenzhen…

Video Series – Touring Factories in Shenzhen – [Link]

4 Aug 2014

## EEVblog #646 – Gravity Detection Using A Frequency Counter!

Did you know you can use your frequency counter to detect gravity? You’ve likely done it before and you didn’t even know it!
Dave demonstrates the phenomenon of 2g-tipover on quartz crystal oscillators in an Agilent 53131A frequency counter.

EEVblog #646 – Gravity Detection Using A Frequency Counter! – [Link]

2 Aug 2014

## Touring in Shenzhen video series from Limpkin

Touring factories in Shenzhen: Visiting an assembly line, Seeedstudio and a CNC shop

Shenzhen is the geek’s paradise and can be described as an awesome concentration of very different companies, all within an hour cab ride from your hotel. If you ever go there, I highly recommend you to have a look at Ian’s article to get practical informations. Shenzhen is located in the south of China, right next to the border with Hong Kong. I therefore decided to spend my first day in this former British colony to buy myself a nice camera to bring back cool videos of my adventures.

[via]

Touring in Shenzhen video series from Limpkin – [Link]