AD5933 Part 3 (Pinout and Arduino Library Introduction)

 AD5933 Part 3

AD5933 - Part 2

 AD5933 - Part 2

AD5933 阻抗转换器 网络分析仪模块 1M 采样率 12bit 分辨率 测量电阻 - ¥199 

AD5933 - Part 1

AD5933 1 MSPS, 12-Bit Impedance Converter

AD5933 1 MSPS, 12-Bit Impedance Converter, Network Analyzer Data Sheet 

GENERAL DESCRIPTION 

The AD5933 is a high precision impedance converter system solution that combines an on-board frequency generator with a 12-bit, 1 MSPS, analog-to-digital converter (ADC). 

The frequency generator allows an external complex impedance to be excited with a known frequency. 

The response signal from the impedance is sampled by the on-board ADC and a discrete Fourier transform (DFT) is processed by an on-board DSP engine. 

The DFT algorithm returns a real (R) and imaginary (I) data-word at each output frequency. 

Once calibrated, the magnitude of the impedance and relative phase of the impedance at each frequency point along the sweep is easily calculated. 

This is done off chip using the real and imaginary register contents, which can be read from the serial I2C interface. 

A similar device, also available from Analog Devices, Inc., is the AD5934, a 2.7 V to 5.5 V, 250 kSPS, 12-bit impedance converter, with an internal temperature sensor and is packaged in a 16- lead SSOP.

How to improve my Blogger site - Part 2

How to improve my Blogger site - Part 2

Longtime Stack Overflow Mods Quitting Because of Toxic Culture - Nate Swanner, 2019oct17

Late last year, Stack Overflow began actively trying to manage its often-toxic community with new rules. Unfortunately, it might not be working, and longtime moderators are fed up.

In its original messaging effort, Stack Overflow was full of platitudes; for example, it ordered the community to be “clear and constructive” and “kind and friendly.” It wanted to be “a community that is rooted in kindness, collaboration, and mutual respect.” Still, moderators aren’t feeling the love.

In a blog post, long-tenured Stack Overflow moderator George Stocker outlined three main points for his departure. First, he says, the company has “forgotten how to lead, how to persuade, and how to talk with the community,” noting it has been in decline since at least 2014. “They no longer want to build a relationship with the community they have.”

He also feels those at the company make decisions about moderator reviews and removals unilaterally, and mods (who are unpaid) are being treated more like volunteers than partners in building a better community. This all culminates in Stocker’s third point: he’s lost faith in Stack Overflow leadership.

Stocker also took to Twitter. In a long thread, Stocker says two other long-time moderators have quit, bringing the site’s total down to 19 from 22. Stack Overflow staffer “@shog9” shared Stocker’s post on Twitter, adding he’s been saying goodbye too much of late, which seems a direct reference to Stocker’s point about long-time moderators quitting:

Been saying goodbye a lot lately. Lotta noise on twitter, so I wanna make something clear: these are good people who care deeply Stack Overflow; they’re leaving not because of the work in front of them, but because they feel we don’t have their backs. https://t.co/KLczVlUJd8— Shog9 (@shog9) October 15, 2019

How Best to Moderate?

In an unrelated interview with The Verge, Twitch CEO Emmett Shear had some interesting thoughts on how to moderate the site he runs. He uses Reddit communities as an example, saying: “The one with good, strong moderation, in many ways, is actually the place with freer speech. Because it was actually the place where people could express themselves and not just get destroyed by trolls and abuse and harassment.”

As Shear also points out, Twitch is giving its moderators and channel owners better moderation tools… and is doing so specifically because streamers didn’t feel they had enough tooling at their disposal to moderate their channels as they needed or wanted to. “We decided we had to do better. And I think it’s a big step in the right direction,” Shear adds.

Stack Overflow and Twitch are very different entities, but have a similar issue: toxicity. The difference is Twitch has decided its streamers and moderators are partners in an effort to stomp out bad actors, and Stack Overflow has decided something different. Furthermore, Stocker says, Stack Overflow has stopped listening to moderators:

All criticisms of company actions have been lumped together as “this is just meta, they’re malcontents, we don’t need to listen to them.” They do not partake in the activities that are needed to build and grow a community. They overwork their Community Managers and force them to act as intercessors without giving them the authority to help build the community.

In 2018, Stack Overflow placed the onus on users to shape up. It didn’t work; its 2019 developer survey shows 73 percent of users feel the site is “just as welcoming,” with the most popular request being a fix for the “community culture.”

At the time, we wrote: “When you’ve got to wade through a river of ego and spite before being told to ‘Google it,’ we start to wonder how long people will tolerate a Stack Overflow where a ‘cultural shift’ hasn’t yet taken hold.”

Stack Overflow has failed its moderators, and Twitch’s position shows supporting your moderators is the best way to improve your community. Unfortunately, Stack Overflow’s toxic corporate culture seems to get in the way. We know where moderators have drawn the line, but we’re still waiting to see when users give up on Stack Overflow.

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Rpi CM4 Setting Up Notes - Part 2 (IO Board)

 Rpi CM4 Setting Up Notes - Part 2 (IO Board)

Tunnel diode models — Carmon Dale Thiems, University of Missouri, 1969

Tunnel diode models for electronic circuit analysis program - Carmon Dale Thiems, University of Missouri, 1969

Tunnel Diode Models

Abstract

"In this paper ECAP models for the tunnel diode are presented. Results showing the model, the current-voltage charateristics [sic] are discussed. Operation in typical circuits is presented. A summary of the current state of the art in modeling appears in Appendix I. Since ECAP is only structured to accept piecewise-linear models of these devices, that type of model is presented here. All of the models are developed to approximate the typical tunnel diode current-voltage characteristic"--Introduction, page 1.

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Tunnel Diode 2BS4A Load Line Analysis and Oscillator Design

 Tunnel Diode 2BS4A Load Line Analysis and Oscillator Design

Now I have found a document about 2BS4A load line and parameters for designing an astable. 

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