SMA Connector Footprint Design For Open Source RF Projects

When you first start out in the PCB layout game and know just enough to be dangerous, you simply plop down a connector, run a trace or two, and call it a hack. As you learn more about the finer points of inconveniencing electrons, dipping toes into the waters of higher performance, little details like via size, count, ground plane cutouts, and all that jazz start to matter, and it’s very easy to get yourself in quite a pickle trying to decide what is needed to just exceed the specifications (or worse, how to make it ‘the best.’) Connector terminations are one of those things that get overlooked until the MHz become GHz. Luckily for us, [Rob Ruark] is on hand to give us a leg-up on how to get decent performance from edge-launch SMA connections for RF applications. These principles should also hold up for high-speed digital connections, so it’s not just an analog game.

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Flexible Actuator Flaps For 100,000,000 Cycles Without Failure

Flexible PCBs are super-useful things, but they can have a limited fatigue life. [Carl Bugeja] has been using them to create flexible actuators, though, and he’s getting an amazing 100,000,000 cycles out of them after some rigorous development.

[Carl] explores all manner of optimizations to his flippy actuators in the video. He tried making them oscillate faster by putting a hole in the middle to reduce drag. Other tricks include getting the arm thickness just right, and experimenting with rigidity through adding or removing sections of soldermask.

Fundamentally, though, he learned the key to longevity laid in the copper traces on the flex PCBs themselves. After enough flexural cycles, the traces would fail, killing the actuator. He experimented with a variety of solutions, eventually devleoping a ruggedized two-arm version of his actuator. Twenty samples were put to the test, oscillating at 25 Hz for two weeks straight. All samples survived the test, in which they were put through around 107,820,000 cycles.

[Carl] has put in plenty of hard work on this project, and his actuators have come a long way since we saw them last. He hopes to use the better actuators to improve his FlexLED display. Video after the break.

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More Ideas For Setting Up An Electronics Workbench

Setting up an electronics work area is a highly personal and situational affair, with many interesting problems to be solved, and for many of us, significant budget constraints. The requirements for electronics development vary wildly depending upon the sort of work to be undertaken, but there is core equipment that many of us would consider a bare minimum for usability. [Badar Jahangir Kayani] is at the start of his career as an electrical engineer, and has documented the kitting out of his personal work areas for others to learn from.

A place for everything, everything in its place

As we already touched upon, the cost is often the main driving factor determining what we end up with, and this cost-vs-performance/quality tradeoff is what makes some of us fret over a buying decision. Buying secondhand off eBay is an option, but a lack of warranty and the unknowable condition are not great selling points.

[Badar] has a good grasp of the basic concepts of usability, such as keeping the most frequently used tools, instruments, and components out in the open. Less frequently used stuff is stored in drawers, bins, and compartment boxes. Buying the same storage systems keeps things as consistent as much as possible since it makes storing them easier. We were particularly interested in the use of the cloud-based database solution, Airtable used to create a parts database for minimal outlay.

Oooh! Cable tray action

There is also a lot of detail about how to walk that cost/quality/performance tightrope and get the best-valued gear currently on the market. Some notable examples are the UNI-T UT61E Digital Multimeter for general test use, the Controleo3 reflow controller for SMT assembly, and the Omnifixo OF-M4 magnetic fixament kit for that fiddly wiring part. [Badar] also recommends the FumeClear Solder Fume Extractor, although they lament that particular bit of kit is still under evaluation.

Obviously, we’ve talked about work areas a lot on these pages, like this time. For those with more space, this flippin’ awesome bench will be of interest, and if space is tight (or travel is a regular thing) might we suggest this 3D printed DIN-rail mounting cube as a starting point?

Exploiting Hardware-Level Parallelism In The Manticore Hardware-Accelerated RTL Simulator

Before a chip design is turned from a hardware design language (HDL) like VHDL or Verilog into physical hardware, testing and validating the design is an essential step. Yet simulating a HDL design is rather slow due to the simulator using either only a single CPU thread, or limited multi-threading due to the requirements of fine-grained concurrency. This is due to the strict timing requirements of simulating hardware and the various clock domains that ultimately determine whether a design passes or fails. In a recent attempt to speed up RTL (transistor) level simulations like these, Mahyar Emami and colleagues propose a custom processor architecture¬†– called Manticore – that can be used to run a HDL design after nothing more than compiling the HDL source and some processing. Continue reading “Exploiting Hardware-Level Parallelism In The Manticore Hardware-Accelerated RTL Simulator”

Op-Amp Challenge: A Low Noise Amplifier For Those Truly Low Noise Measurements

When something is described as “Low Noise”, it is by the nature of the language a relative phrase. The higest quality magnetic tape is low noise compared to its cheaper sibling for example, but still has noise many would consider unacceptable. In instrumentation however, “Low Noise” has to really mean just that, with a range of specialist techniques to produce circuitry with a truly low noise level for the most demanding of signal applications. As an example [Floydfish] has created a low noise instrumentation amplifier that should serve as a learning exercise for anyone interested in pushing low noise circuitry to the limit.

Anyone who can dredge the hazy recesses of their mind for barely-remembered electronics lectures will know that the overall noise figure of a system is dictated by that of its first component. Thus perhaps the most interesting part of the schematic is at the input, where a row of low-noise op-amps are presented in parallel. We have to admit having to look this one up, to find that it’s a technique whereby the signal outputs of each chip are the same and thus sum, while the noise output of each is different and thus the summed noise output is proportionally lower. This stage is then followed by a buffer and a set of filters for different output frequency ranges.

Our op-amp competition of which this is a part is certainly delivering the goods when it comes to the amny techniques with which these versatile parts can be used. Few of us may need to make such a low noise amplifier, but at least now we’ve learned how.

Op-Amp Challenge: Light Up Breadboard Shows Us The Signals

Most Hackaday readers will no doubt at some point used a solderless breadboard for prototyping. They do the job, but sometimes their layout can be inflexible and keeping track of signals can be a pain. There’s a neat idea from [rasmusviil0] which might go some way to making the humble breadboard easier to use, it’s a breadboard in which each line is coupled via an op-amp buffer to an LED. In this way it can be seen at a glance some indication of the DC voltage present.

It’s an idea reminiscent of those simple logic probes which were popular years ago, but its implementation is not entirely easy. Each circuit is simple enough, but to replicate it across all the lines in a breadboard makes for a huge amount of quad op-amp chips stuffed onto one piece of stripboard as well as a veritable forest of wires beneath the board.

The effect is of a breadboard crossed with a set of blinkenlights, and we could see that for simple digital circuits it could have some utility if not so much for higher frequency or analogue signals. Certainly it’s an experiment worth doing, and indeed it’s not the first tricked out breadboard we’ve seen.

Op-Amp Challenge: Get More From A Single Wire With An Analogue Adder

It’s been a running battle in some quarters for years, whether analog sensor processing is better than digital. Proponents of digital are sometimes driven by lack of familiarity with analog circuitry, while analog die-hards point to delays and software crashes in microcontrollers. We’d probably toe the line that a mixture of the two skills is best, but [paul] has gone full-on for the analog side with his position and limit sensor for a remote telescope. The ‘scope had only one control wire carrying a digital signal, so how was he to get extra information down it? The solution was to overlay a DC voltage, and use a summing network composed of a series of op-amps to encode position and limit data as voltage.

In operation, the circuit is a straightforward DC summing amplifier of the type that op-amps were designed for and at which they excel. We’re not so sure it needs the high-precision resistors and the choice of op-amps seems the wrong way round with the AD8532’s high current output being better suited to driving the line than straightforward summing, but we can see it does the job. If you’re after a demonstration of a DC summing amplifier using an op-amp, here’s your project. Meanwhile if you’re curious about an op-amp inside the black box, take a look at one of the simplest integrated circuit op-amps ever made.