Author Archives: DP

App note: Silicon Labs’ TS3004 VS. the CMOS 555 – Determining lowest supply current for battery-powered applications

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Good read on this app note from Silicon Labs comparing their low power but obsolete timer. Link here (PDF)

The 555 timer is the workhorse of ICs, with close to a billion of them manufactured every year. Introduced in 1972, the 555 is still in widespread use because of its ease of use, reasonable price, and good stability. It can be found in a wide variety of applications for oscillation, timing and pulse generation. But what if you need a timer IC for ultralong life, low-frequency battery-powered/portable applications where a low supply current is a requirement? Is the CMOS555 timer your best option?

App note: Single-cell regulated Q-pump draws low quiescent current

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Q-pump an alternative to inductor charge pump boost regulator for low power and sleepy microcontroller from Silicon Labs. Link here (PDF)

In the switch-mode power supply world, capacitor-based charge pumps (or Q-pumps) generally aren’t useful for heavy lifting, but work well in niche micropower applications where space is at a premium. They work best in applications where the output voltage is an integer multiple of the input voltage, which are operating points that result in peak efficiency. However, they can also shine when powered from a variable input like a battery, particularly when quiescent battery drain is more important than heavy-load efficiency. This might be the case when powering a microcontroller that spends most of its life sleeping.

Free PCB coupon via Facebook to 2 random commenters

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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.

Sweeperino, Arduino based test instrument

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Ashhar Farhan (VU2ESE) made an Arduino based sweeper for ham radio homebrewing, that is available on GitHub:

The Sweeperino a very useful Arduino based test instrument. It is the following:
*A very stable, low noise signal generator from 4 MHz to 160 MHz without any spurs
*A high precision power meter with 90 db with 0.2db resolution
*A sweeper that can be your antenna analyzer, plot your crystal or band pass filter through the PC
*It fits in your jacket
*It can be assembled in an evening
*Costs about $50 in new parts

See the full post on VU2ESE’s radio experiments blog.

“Cigarette Pack”- 14MHz SSB QRP Micro-Transceiver

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Peter Rachow (DK7IH) built a 14MHz SSB QRP Micro-transceiver into a cigarette packet size case:

This article describes the “Cigarette Pack” SSB QRP transceiver” for 14MHz that I first had mentioned some months before. Recently, when taking it from the shelf, the transceiver dropped to the floor and was severely damaged. This lead to serious defects in the front panel area, the main frame, the cabinet and so on. The interior parts were, luckily, not affected by the crash. So, I had to revise the whole radio, make a new front panel and cabinet, ply the frame straightly (as far as possible) and so on. This is the full description of the rig now to complete the files here. The good news: The radio is fine again and fully operational!  And the even better news: I still have not started smoking!

See the full post on Amateur Radio Engineering Projects blog.