Improving Active Loads

May 3, 2015 by Brian Benchoff 6 Comments

[Texane]’s job requires testing a few boards under a set of loads, and although the lab at work has some professional tools for this it seemed like a great opportunity to try out the Re:load 2. It’s a nifty little active load that’s available can of course be improved with an injection of solder and silicon.

While the Re:load 2 is a nice, simple device that can turn up to 12 Watts directly into heat, it’s not programmable. The ability to create and save load profiles would be a handy feature to have, so [Texane] took a Teensy 3.1 microcontroller and installed a resistor divider in front of the Re:load’s amplifier. A simple script running on a computer allows [Texane] to set the amount of current dumped and automate ramps and timers.

There is a more fundamental problem with the Re:load; the lowest possible current that can be dumped into a heat sink is 90mA. [Texane] replace the amplifier with a zero-drift amp that brought that 90mA figure down to 7mA.

Of course the Re:load and Teensy 3.1 are sold in the Hackaday store, but if you’re looking for a ready-built solution for a computer-controlled active load you can always check out the Re:load Pro, a fancy-smanchy model that has an LCD. The Pro costs more, and [Texane] just told you how to get the same features with the less expensive model we’re selling, though…

Adding PID Control To A Non-Adjustable Iron

April 28, 2015 by George Graves 10 Comments

Do remember your first soldering iron? We do. It plugged into the wall, and had no way to adjust the temperature. Most people call these kind of irons “fire starters.” Not only are they potentially unsafe (mainly because of the inadequate stand they come with) they can be hard to use, slow to heat up, and you never know what temperature you are soldering at.

[Mike Doughty] wondered if you could hack a cheap iron to be temperature controlled. He began by taking apart an iron, and adding a K-type thermocouple to the mica heating element with the help of a fiberglass sleeve. After a few tries at fitting and finding the right placement for the thermocouple, he then reassembled the iron, and attached everything to an off-the-shelf industrial PID controller.

Not one to trust that everything was working, [Mike] began to test the iron. He used a Hakko FG-100 soldering iron tip thermometer to measure the “real” temperature of tip, and compared it to the value the K-type thermocouple was reporting it to be. The results were fairly impressive (as seen in the video after the break). Only about 10 degrees out. Not too shabby.

He concluded that although it did work, it wasn’t a replacement for a high quality soldering station. We suspect the real problem with this idea is that the mica heating element is way to slow to respond to any thermal load that the tip is given (but then neither did the unmodified iron.) If you’re interested in hacking together your own soldering station, you might be interested in the open source soldering iron driver.

[via Dangerousprototypes]

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Workbench Eye Candy From Around The World

April 27, 2015 by George Graves 14 Comments

The workbench. We’re always looking for ways to make the most out of the tools we have, planning our next equipment purchase, all the while dealing with the (sometimes limited) space we’re allotted. Well, before you go off and build your perfect electronics lab, this forum thread on the EEVblog should be your first stop for some extended ~~drooling~~ research.

You’ll find a great discussion about everything from workbench height, size, organization, shelf depth, and lighting, with tons of photos to go with it. You’ll also get a chance to peek at how other people have set up their labs. (Warning, the thread is over 1000 posts long, so you might want to go grab a snack.)

We should stop for a moment and give a special note to those of you who are just beginning in electronics. You do not need to have a fancy setup to get started. Most of these well equipped labs is the result of being in the industry for years and years. Trust us when we say, you can get started in electronics with nothing more than your kitchen table, a few tools, and a few parts. All of us started that way. So don’t let anything you see here dissuade you from jumping in. As proof, we’ve seen some amazingly professional work being done with the most bare-bones of tools (and conversely, we seen some head-scratching projects by people with +$10,000 of dollars of equipment on their desk.)

Here’s some links that you might find handy when setting up a lab. [Kenneth Finnegan] has a great blog post on how his lab is equipped. And [Dave Jones] of the EEVblog has a video covering the basics. One of the beautiful things about getting started in electronics is that used and vintage equipment can really stretch your dollars when setting up a lab. So if you’re looking into some vintage gear, head on over to the Emperor of Test Equipment. Of course no thread about workbenches would be complete with out a mention of Jim Williams’ desk. We’ll leave the discussion about workbench cleanliness for the comments.

DIY Wet Media Blast Cabinet

April 26, 2015 by Rich Bremer 27 Comments

Most people have heard of sand blasting, a process used for cleaning parts by spraying a high pressure air and sand mixture. At this speed, the sand becomes abrasive and will remove paint, rust and general gunk leaving a clean surface behind. There is one downside to the process, breathing the silica dust created by the sand blasting process can lead to a lung disease called silicosis, which is not curable and can even lead to death.

[Roger] wanted to clean his motorcycle parts and decided to build a wet media blasting cabinet. Unlike sand blasting, wet media blasting mixes the cleaning media with water instead of air. The media and water slurry is sprayed at the part needing cleaning and has the same effect as sand blasting without creating any dust.

As you can clearly see from the image, the main blasting chamber is made from a 55 gallon plastic drum. It even has a removable lid on one side to make loading in parts easy. A large hole was cut into the drum in order to install a window. Look close – there is even a wind shield wiper from a car installed on the inside of the window to aid in seeing the part being cleaned!

Underneath the blasting chamber is another plastic drum cut in half. This serves as a slurry tank. A regular pool pump is used to both agitate the slurry mixture and power the spray nozzle. Overall, [Roger] is happy with his blast cabinet made from found parts and says it has become his all-time favorite cleaning device. He says that the part surface finish obtained was well worth the effort building the blast cabinet.

DIY Dust Cyclone A Traffic Cop Would Be Proud Of

April 26, 2015 by Rich Bremer 45 Comments

Sure, having a wood shop is super handy but it also can get real dusty. Hooking up a shop vac to suck up dust coming off a wood-cutting machine works for all of 3 minutes before the vacuum’s filter gets clogged with dust. There is a solution, though, and it is called a dust separator.

A dust separator does just as its name suggests, it separates dust from air. There is a common type of dust separator made in the DIY community, it has a cone-shaped body and is generally referred to as a cyclone-style. [Dror] built his own cyclonic dust collector out of an odd object… a traffic cone. Looking at it now, we wonder why this isn’t much more common!

The dusty air enters the PVC pipe and ends up spinning around the inside of the cone. Since the dust particles have mass, they are thrown to the outside of this chamber as they spin. They lose speed and drop down into the 5 gallon bucket below. The dust-free air then outlets through the top of the dust separator which is connected to a shop vac.

You’ll notice that [Dror] decided to use threaded rod to hold his separator pieces together. While this may seem like overkill, he had tried several glues and could not get any to stick to the traffic cone!

If you’d like to get in on the dust separator action but don’t have a traffic cone, they can also be 3D printed or made from metal.

The Ultimate Tool For Homebrew PCB Manufacturing

April 26, 2015 by Brian Benchoff 37 Comments

While OSHPark, Seeed Studio, and DirtyPCB have taken most of the fun and urgency out of making your own circuit boards at home, there are still a few niche cases and weird people who like to go it alone. For them, [Jarzębski] has created the ultimate homebrew PCB manufacturing solution (.pl, here’s the Google translatrix).

[Jarzębski] is using UV-sensitive photomasks for his PCBs, but he’s not doing something simple like a blacklight to develop his boards. He’s using a 30 Watt UV LED for exposing his boards. This, of course, generates a lot of heat and to mitigate that he’s added a Peltier cooler, temperature sensor, and a fan to cool off this retina-burning LED. 30 Watts will get the job done, considering [Jarzębski] was using a quartet of 4.5W LEDs before this build.

Developing a PCB is only one part of the equation; you need to etch it, too. For this, [Jarzębski] is using a small 1.6 Liter aquarium and four aquarium heaters for dunking 120mm x 120mm PCBs in the tank. There’s no mention of what chemistry [Jarzębski] is using – ferric chloride, cupric chloride, or otherwise – but the heaters and aerator should make etching go very smoothly.

There’s a video (English) going over the rest of the project below.

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Massive Wood Joints With Chainsaw Mortiser

April 25, 2015 by Rich Bremer 21 Comments

One common joinery method used in wood working is the mortise and tenon. A mortise is basically a hole in a piece of wood and the tenon is another piece of wood cut to tightly fit in that hole. The tenon is usually secured in place with either glue or a wooden pin or wedge.

The folks over at [WayOutWest] were building a fence and needed a way to cut a bunch of mortises in 4×4 inch posts to accept 2×6 inch rails. Although they had a chainsaw, trying to cut a mortise with it by hand turned out to be super dangerous because the chainsaw would kick up every time the tip of the blade touched the wood. The team had some parts kicking around so they made a fixture to hold the chainsaw as it is plunged into the 4×4’s.

The contraption’s frame is made from an old scaffolding stand and the slides are just pipes inside of pipes. The chainsaw is bolted to the slide and a lever moves it forward and back. A second lever moves the piece of wood getting mortised up and down so that the mortise can be cut to any width. This is a pretty ingenious build that only cost a little effort and will end up saving a bunch of time mortising countless fence posts.

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