App note: Transformers

via Dangerous Prototypes

an_minicircuits_AN20-002

App note from Mini-Circuits on transformer types and some basics of them. Link here (PDF)

The purpose of this application note is to describe the fundamentals of RF and microwave transformers and to provide guidelines to users in selecting proper transformer to suit their applications. It is limited to core-and-wire and LTCC transformers.

 

App note: USB hardware design guide

via Dangerous Prototypes

1apps

An app note from Silicon Labs with design guidelines for implementing USB host and device applications using USB capable EFM32 microcontrollers. Link here. (PDF!)

This document will explain how to connect the USB pins of an EFM32 microcontroller, and will give general guidelines on PCB design for USB applications. First some quick rules-of-thumb for routing and layout are presented before a more detailed explanation follows.
The information in this document is meant to supplement the information already presented in Energy Micro application notes AN0002 Hardware Design Considerations and AN0016 Oscillator Design Considerations, and it is recommended to follow these guidelines as well.

Reamer Regrinding Using a Toolpost Spindle

via hardware – Hackaday

How often have you wished you could reduce the size of a drillbit? [Ben Katz] has a bunch of projects in mind that use a tight-tolerance 22mm bore–but he didn’t have a 22mm reamer handy. Rather than buy one, he thought, why not regrind a larger one to the right size?

He first ground down the shank to fit in the lathe’s drill chuck. Once it was loaded into the chuck,  he reground the edge of a 7/8″ (22.225mm) reamer, reducing its diameter down to 22mm by spinning it on his lathe in conjunction with a toolpost spindle with a grinding wheel attached. The final diameter was 21.995mm—off by 5 microns!

[Ben]’s homebuilt spindle is a cool project in itself, and we publish a lot of posts about those handy tools. Check out our pieces on a brushless DC motor used as a CNC spindle, and this 3D printer outfitted with a spindle. Also check out [Ben]’s electric tricycle build we featured a few years ago.


Filed under: hardware, tool hacks

Free PCB coupon via Facebook to 2 random commenters

via Dangerous Prototypes

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Facebook with a coupon code for the PCB drawer.
  • Limit one PCB per address per month, please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

PRECIsion Power SUpply project

via Dangerous Prototypes

pics-block-600

PreciPSU, a high performance power supply project from Mare & Gal Electronics:

PreciPSU is an attempt to build high performance power supply. The idea started few years ago but it was never realised. Some major target performance specs are as follows:

  • three isolated channels
  • around 50W per channel
  • 24V/3A output per channel
  • lowest possible ripple at fastest response
  • small size
  • programmable via USB
  • nice housing with minimalist user interface (2 plugs per channel, knob, button and small display

Read the full post here.

Michael Reeves and the ridiculous Subscriber Robot

via Raspberry Pi

At the beginning of his new build’s video, YouTuber Michael Reeves discusses a revelation he had about why some people don’t subscribe to his channel:

The real reason some people don’t subscribe is that when you hit this button, that’s all, that’s it, it’s done. It’s not special, it’s not enjoyable. So how do we make subscribing a fun, enjoyable process? Well, we do it by slowly chipping away at the content creator’s psyche every time someone subscribes.

His fix? The ‘fun’ interactive Subscriber Robot that is the subject of the video.

Be aware that Michael uses a couple of mild swear words in this video, so maybe don’t watch it with a child.

The Subscriber Robot

Just showing that subscriber dedication My Patreon Page: https://www.patreon.com/michaelreeves Personal Site: https://michaelreeves.us/ Twitter: https://twitter.com/michaelreeves08 Song: Summer Salt – Sweet To Me

Who is Michael Reeves?

Software developer and student Michael Reeves started his YouTube account a mere four months ago, with the premiere of his robot that shines lasers into your eyes – now he has 110k+ subscribers. At only 19, Michael co-owns and manages a company together with friends, and is set on his career path in software and computing. So when he is not making videos, he works a nine-to-five job “to pay for college and, y’know, live”.

The Subscriber Robot

Michael shot to YouTube fame with the aforementioned laser robot built around an Arduino. But by now he has also be released videos for a few Raspberry Pi-based contraptions.

Michael Reeves Raspberry Pi Subscriber Robot

Michael, talking us through the details of one of the worst ideas ever made

His Subscriber Robot uses a series of Python scripts running on a Raspberry Pi to check for new subscribers to Michael’s channel via the YouTube API. When it identifies one, the Pi uses a relay to make the ceiling lights in Michael’s office flash ten times a second while ear-splitting noise is emitted by a 102-decibel-rated buzzer. Needless to say, this buzzer is not recommended for home use, work use, or any use whatsoever! Moreover, the Raspberry Pi also connects to a speaker that announces the name of the new subscriber, so Michael knows who to thank.

Michael Reeves Raspberry Pi Subscriber Robot

Subscriber Robot: EEH! EEH! EEH! MoistPretzels has subscribed.
Michael: Thank you, MoistPretzels…

Given that Michael has gained a whopping 30,000 followers in the ten days since the release of this video, it’s fair to assume he is currently curled up in a ball on the office floor, quietly crying to himself.

If you think Michael only makes videos about ridiculous builds, you’re mistaken. He also uses YouTube to provide educational content, because he believes that “it’s super important for people to teach themselves how to program”. For example, he has just released a new C# beginners tutorial, the third in the series.

Support Michael

If you’d like to help Michael in his mission to fill the world with both tutorials and ridiculous robot builds, make sure to subscribe to his channel. You can also follow him on Twitter and support him on Patreon.

You may also want to check out the Useless Duck Company and Simone Giertz if you’re in the mood for more impractical, yet highly amusing, robot builds.

Good luck with your channel, Michael! We are looking forward to, and slightly dreading, more videos from one of our favourite new YouTubers.

The post Michael Reeves and the ridiculous Subscriber Robot appeared first on Raspberry Pi.