Free PCB Sunday: Pick your PCB

BP-600x373

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

Be the first to comment, subscribe to the RSS feed.

from Dangerous Prototypes https://ift.tt/2MC1fWB

App note: AC ripple current calculations solid tantalum capacitors

an_vishay_tantalum_limit

Application note from Vishay on power and voltage limitations of solid tantalum capacitors for both low and high frequency applications. Link here (PDF)

Solid tantalum capacitors are preferred for filtering applications in small power supplies and DC/DC converters in a broad range of military, industrial and commercial systems including computers, telecommunications, instruments and controls and automotive equipment. Solid tantalum capacitors are preferred for their high reliability, long life, extended shelf life, exceptional stability with temperature and their small size. Their voltage range is 4 to 50 volts for the most common types. Tantalum chip capacitors for surface mount applications are manufactured in very small sizes and are compatible with standard pick-and-place equipment.

from Dangerous Prototypes https://ift.tt/2L7cLV0

App note: Electrolytic capacitor lifetime estimation

an_jianghai_elcap_lifetime_est

Lifetime estimation methods for elcap app note from Jianghai. Link here (PDF)

Aluminum Electrolytic Capacitors (“alu-elcaps”, “elcaps”) are essential for the function of many electronic devices. Ever increasing for enhanced efficiency, the expanding utilization of renewable energy and the continuous growth of electronic content in automotive applications have driven the usage of these components.

In many applications, the lifetime of electronic devices is directly linked to the lifetime of the elcaps inside. To ensure reliable operation of electronic devices for a defined period, a thorough knowledge of the vital properties of elcaps is mandatory.

The present article outlines the construction of elcaps and explains related terms like ESR, ripple current, self-heating, chemical stability, and lifetime. Two estimation tools for obtaining elcap lifetime approximations in an application are introduced and illustrated by an example.

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Open source RISC – Eclipse with RISC-V on the SiFive HiFive1 board

sifive-hifive1-board

Erich Styger writes:

Open Source software has been around for decades. But open source on hardware especially microcontroller is not much a reality these days. But there is something which might change this: RISC-V is a free and open RISC instruction set architecture and for me it has the potential to replace some of the proprietary architectures currently used. RISC-V is not new, but it gets more and more traction in Academia (no surprise). Not only because it is open: Think about all the recent security issues with proprietary architectures: Spectre, Meltdown, and Foreshadow just be the most recent one.
I wanted to play with RISC-V for over a year, but finally a week ago I did one of these “hey, let’s buy that board” thing again. Sometimes these boards get on a pile to wait a few weeks or longer to get used, but that one I had to try out immediately :-).

More details on MCU on Eclipse site.

from Dangerous Prototypes https://ift.tt/2BiTmkv

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:

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.

from Dangerous Prototypes https://ift.tt/2MVVTlU

Teardown of an MEDA PLM-100 AC Magnetometer

PLM100

Kerry Wong did teardown of an MEDA PLM-100 AC magnetometer:

I did a teardown a while ago on a cheap eBay electromagnetic radiation detector, and if you recall the performance of that meter was mediocre at the best. This time around though, I’ve got a MEDA PLM-100 AC magnetometer. Since MEDA (Macintyre Electronic Design Associates) specializes in fluxgate and search coil magnetometers, this PLM-100 magnetometer is a piece of professional test equipment. In this blog post, you will see some teardown pictures and for those who want to see some real world actions you can take a look at the video included towards the end.

See the full post on his blog here.

Check out the video after the break.

from Dangerous Prototypes https://ift.tt/2OF7I0a

Free PCB Sunday: Pick your PCB

BP-600x373

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

Be the first to comment, subscribe to the RSS feed.

from Dangerous Prototypes https://ift.tt/2MblqLn

App note: Replacing mechanical potentiometers with digital potentiometers

an_analog_AN1121

Another application note from Analog Devices this time about the superiority of digital over mechanical potentionmenters. Link here (PDF)

Potentiometers have been widely used since the early days of electronic circuits, providing a simple way to calibrate a system, adjusting offset voltage or gain in an amplifier, tuning filters, controlling screen brightness, among other uses. Due to their physical construction, mechanical potentiometers have some limitations inherent to their nature, such as size, mechanical wear, wiper contamination, resistance drift, sensitivity to vibration, humidity, and layout inflexibility.

Digital potentiometers are designed to overcome all these problems, offering increased reliability and higher accuracy with smaller voltages glitches. The mechanical potentiometer has now been relegated to environments where the digital potentiometer cannot be a suitable replacement, such as high temperature environments or in high power applications.

Comparing both technologies is the simplest way to discern which is the optimal solution for your system.

from Dangerous Prototypes https://ift.tt/2nyGVXY

App note: Precision signal conditioning for high resolution industrial applications

an_analog_AN1264

App note from Analog Devices on robust precision signal conditioning. Link here (PDF)

Industrial measurement and control systems often need to interface to sensors while operating in noisy environments. Because sensors typically generate very small electrical signals, extracting their output from the noise can be challenging. Applying signal conditioning techniques, such as amplification and filtering, can aid in the extraction of the signal because these techniques increase the sensitivity of the system. The signal can then be scaled and shifted to take full advantage of high performance ADCs.

from Dangerous Prototypes https://ift.tt/2vEySxg

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:

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.

from Dangerous Prototypes https://ift.tt/2M6jGmG