#FreePCB via Twitter to 2 random RTs

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter 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.

PortL2 – Portable electric vehicle charger

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Here’s a project log covering the build of a portable level 2 electric vehicle charger by Andrew Rossignol:

This is a battery-powered EV charger that allows destination charging where L2 charging is not ordinarily available. This can be used as a range extender for electric vehicles with smaller batteries. This system has a ~7kWh battery which should charge my Cadillac ELR to more than 60%. This has been a fun project with plenty of lessons learned.

More info at The Resistor Network.

Check out the video after the break. Continue reading “PortL2 – Portable electric vehicle charger”

App note: Why honest weigh scales are application specific

App note from Maxim Integrated discussing strain gauge and accompanying circuit are used in today’s weight measurement applications. Link here (PDF)

Current laws and regulations require honesty, tolerance, and accuracy in weigh scales. The most commonly used weight-measurement element is the strain gauge. This application note explains how strain gauges are useful in multiple applications that must measure stress and pressure and their effects. The electronics of honest weigh scales are varied, and can provide the resolution and accuracy that each application demands.

App note: How to shrink your USB Type-C battery charger

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Maxim’s app note on a highly compact Type-C charger solution. Link here (PDF)

A highly integrated solution, as seen with the MAX77860 USB Type-C 3A switch-mode charger, dramatically reduces system complexity by integrating the charger, the power path, the Safeout LDO, ADC, and the USB-C CC and BC 1.2 detection in a small 3.9mm x 4.0mm, 0.4mm pitch, WLP package. OTG functionality is seamlessly integrated without the need for an extra inductor. This level of integration simplifies the design, enabling the delivery of more power and more functionality in minimal PCB space.

App note: Overture series high power solutions

Overture Application Note AN-1192

This application note (PDF) from TI discusses the different aspects of the Overture series high-power solutions, and discusses three application circuits: parallel, bridged, and bridged/parallel configurations

The objective is to provide simple high-power solutions that are conservatively designed, highly reliable and have low part count. This document provides three specific, but not unique, application circuits that provide output power of 100W, 200W,
and above. These circuits are the parallel, bridged, and bridged/parallel configurations.
These three circuits are simple to understand, simple to build and require very few external components compared
to discrete power amplifier designs. Simplicity of design and few components make this solution much more reliable than discrete amplifiers. In addition, these circuits inherently possess the full protection of each individual IC that is very difficult and time consuming to design discretely. Finally, these circuits are well know and have been in industry for years.

USB mini media keyboard

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Sven Krasser built a small USB keyboard input device for media control and wrote a post on his blog detailing its assembly:

The project is based on a Pro Micro, an Arduino-compatible ATmega 32u4 board (the 32u4 allowing to easily create USB devices). For iteration 1, I added a couple of buttons and a rotary encoder to a breadboard alongside the Pro Micro to see how I can get media controls over USB to work. Turns out, Nico Hood’s HID library makes that quite simple.

Control the bicycle traffic signal with a Particle Photon

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Glen has been working on a Wi-Fi enabled bicycle traffic signal project:

In the first post in this series, we built a miniature LED bicycle traffic signal using 3D printing, laser cutting, a sticker, and an Adafruit Neopixel Jewel. In this post, we’ll look at bringing the signal to life using a Particle Photon. We’ll start with basic code to blink the traffic signal green, yellow, and red then add code to control the color over the web using the Particle Cloud or locally using an iPad and the Art-Net protocol.

More details on Photons, Electrons, and Dirt blog.

1750Hz tone generator

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Dilshan Jayakody published a new build:

The 1750Hz tone bursts are often used to trigger repeaters. There are several methods to build 1750Hz tone generators which including TC5082 divider, using MCUs, etc.
In this post, I present another 1750Hz tone generator which I built using 74HC4060 high-speed 14-stage binary ripple counter and 7.168MHz crystal. In this design, 74HC4060 is used to drive the crystal and divide its output by 4096. By using 7.168MHz crystal, this circuit produces 1750.0Hz square wave output with a 50% duty cycle.

See the full post on his blog.

App note: Magnetometer placement in mobile devices

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App note from Kionix about magnetometer integration challenges from the mobile equipment point of view, and gives guidelines for the mounting position of the magnetic sensor. Link here (PDF)

Electronic devices contain many parts which can affect a magnetic sensor. When deciding the mounting position, it is necessary to consider the types of materials and the amount of current carried in proximity of the magnetic sensor. Accuracy of an electronic compass depends upon getting clean geomagnetic data from the magnetic sensor output without errors caused by other magnetic elements. These errors need to be canceled by calibration or correction.

App note: Using two tri-axis accelerometers for rotational measurements

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App note from Kionix on utilizing 2 linear accelerometers to determine angular rotational rates. Link here (PDF)

In many applications, customers would like to measure rotational motions (angular velocity, angular acceleration) in addition to linear motions. Most often, gyroscopes are added to their end product to obtain the rotational information. In some instances, customers already have a system that contains two or more accelerometers. With some understanding of fundamental physics, they can extract more than just linear acceleration data from their system.

Decap a Chinese chip at home: Clone or not?

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Sjaak writes, “It has been a while before I posted something useful. On my search for obscure chips, I came around another interesting Chinese chip (which I don’t reveal yet). The chip was advertised as a cheap drop-in replacement for a American IC so I suspected it would be a clone. I wanted to look inside the chip to check if that is true.”

More details at smdprutser.nl

Teardown of a Marconi 2305 modulation meter

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Kerry Wong did a teardown of a Marconi 2305 modulation meter:

I picked up a Marconi 2305 modulation meter off eBay the other day. As the name indicated, a modulation meter is used to measure the modulation characteristics of a source signal. The Marconi 2305 is capable of measuring amplitude/frequency and phase modulated signals from a few hundred kHz all the way up to 2 GHz.
The Marconi 2305 was built sometime between the late 70’s and 80’s. It is a pity that the iconic British Marconi Instruments went under in 1998 and had since changed hands a couple of times.

See the full post on his blog.

Check out the video after the break. Continue reading “Teardown of a Marconi 2305 modulation meter”

#FreePCB via Twitter to 2 random RTs

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter 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.

DIY inline refractometer

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DIY inline refractometer project from Anfractuosity:

The idea of this project is to image the refractometer output, then convert the position of the blue line, to a digital reading, using image processing. The idea is to measure the brix of wort during mash and sparging, so that sparging can be stopped around 1.010 SG, to avoid tannins.

More details on Anfractuosity blog.

Check out the video after the break. Continue reading “DIY inline refractometer”

App note: Light quality – White light parameters

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App note from OSRAM on consistency of colors specifically white lights. Link here (PDF)

White light is not the same as white light. When different light sources are used, color differences may become visible. To understand why this can happen, it is necessary to understand how people perceive color and light. Nevertheless, it is possible to reduce the color shifts by choosing suitable white LEDs combined with an appropriate system setup. This application note provides basic information on optical quantities, color spaces and CIE chromaticity diagrams. Furthermore, it describes how color consistency for white light applications can be achieved.

App note: Ambient lighting design utilizing RGB LEDs

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App note from OSRAM on using RGB LEDs or their MULTILED® for automotive interior lighting. Link here (PDF)

This application note describes the advantages and challenges of utilizing RGB LEDs for ambient lighting control. Besides pointing out practical challenges, preferred solutions for RGB LEDs are outlined and discussed to assist customers with engineering design solutions.

Free PCB coupon via Facebook to 2 random commenters

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:

Continue reading “Free PCB coupon via Facebook to 2 random commenters”