Coffee Table Model Railroad With All The Bells And Whistles (and Lights And Sirens)

December 22, 2017 by 14 Comments

For some, the allure of a real, physical world that you create and control is overwhelming. Combine that with a love of trains, and you get the model railroad. Some are incredibly detailed, and it seems like the larger the layout the better. Not everyone has the real-estate to devote to such a hobby, though, and moving down to N-gauge railroads is often the key to scratching the model railroad itch in a confined space.

But [Chris Plumley]’s complete N-gauge model railroad in a coffee table takes the concept to a new and tiny level. The superlatives to describe this layout are many and begin with the coffee table itself, a free-form sculptural design intended to evoke the natural contours of a landscape. Removing the lid reveals an intricately detailed world that rises up on a lift. The mainline train and a two-station trolley line ply the imaginary world under full computer control, complete with sound effects and animated lighting. An LCD screen stands in for a drive-in movie theater — remember drive-ins? — and a house fire rages on, never to be quenched by the arriving fire engines. And as a bonus, the locomotive has a dash cam to provide an engineer’s eye view of the layout. The attention to detail is wonderful, but the kicker is that this layout has existed in one form or another for sixty years. Talk about persistence!

If you’re intrigued by combining the world of microcontrollers and model railroads, you should really check out this tutorial to get started.

Continue reading “Coffee Table Model Railroad With All The Bells And Whistles (and Lights And Sirens)” →

VFD Puts The Suck Back Into Desoldering Station

December 22, 2017 by 19 Comments

A dedicated desoldering station is a fantastic tool if you’re in the business of harvesting components from old gear. Having heat and suction in a single tool is far more convenient than futzing with spring-loaded solder suckers or braid, but only as long as the suction in the desoldering tool has a little oomph behind it. So if the suction on your solder sucker is starting to suck, this simple VFD can help restore performance.

Luckily for [Mr. Carlson], his Hakko 470 desoldering station is equipped with an AC induction motor, so it’s a perfect candidate for a variable frequency drive to boost performance. He decided to build a simple VFD that boosts the frequency from 60-Hz mains to about 90-Hz, thereby jacking the motor speed up by 50%. The VFD is just a TL494 PWM chip gating the primary coil of a power transformer through a MOSFET. Duty cycle and frequency are set by trimmers, and the whole thing is housed in an old chassis attached to the Hakko via an anachronistic socket and plug from the vacuum tube days. That’s a nice touch, though, because the Hakko can be returned to stock operation by a simple bridging plug, and the video below shows the marked difference in motor speed both with and without the VFD plugged in.

We’ve marveled at [Mr. Carlson]’s instrument packed lab before and watched his insider’s tour of a vintage radio transmitter. Here’s hoping we get to see more of his hopped-up solder sucker in action soon.

Continue reading “VFD Puts The Suck Back Into Desoldering Station” →

Rickroll The Masses With A Coin Cell Throwie

December 22, 2017 by 17 Comments

If there is one educational institution that features on these pages more than any other, it may be Cornell University. Every year we receive a pile of tips showing us the engineering term projects from [Bruce Land]’s students, and among them are some amazing pieces of work. Outside the walls of those technical departments though, we suspect that cool hacks may have been thin on the ground. English Literature majors for example contain among their ranks some astoundingly clever people, but they are not known for their handiness with a soldering iron or a lathe.

We’re happy to note then that someone at Cornell who is handy with a soldering iron has been spreading the love. In the form of coin cell powered throwies that intermittently Rickroll the inhabitants of the institution’s halls of residence. We have few technical details, but they seem to be a simple affair of a small microcontroller dead-bug soldered to a coin cell and a piezoelectric speaker. If we were embarking on such a project we’d reach for an ATtiny of some description, but similar work could be done with a PIC or any number of other families.

The Cornell Daily Sun write-up is more a work of investigative journalism detailing the perplexed residents searching for the devices than it is one of technical reference. We’re pleased to note that the university authorities have a relaxed attitude to the prank, and that no action will be taken against the perpetrator should they be found.

Thus we’d like to take a moment to reach out to the Cornell prankster, and draw their attention to our Coin Cell Challenge competition. There is still time to enter, and a Rickrolling throwie would definitely qualify. This isn’t the first tiny Rickrolling prank we’ve shown you on these pages.

Thanks [Simon Yorkston] for the tip.

Art, Craft, Make, Hack, Whatever

December 22, 2017 by 15 Comments

Anyone who has spent much time reading Hackaday, or in the real world in or around a few hackspaces, will know that ours is a community of diverse interests. In the same place you will find a breathtaking range of skills and interests, people working with software, electronics, textiles, and all conceivable materials and media. And oftentimes in the same person: a bare-metal kernel guru might spend their time in a hackspace making tables from freight pallets rather than coding.

Through it all run a variety of threads, identities if you will, through which the differing flavours of our wider community define themselves. Words like “Hacker” and “Maker” you may identify with, but when I mention words like “Crafter” or “Artist”, perhaps they might meet with some resistance. After all, artists paint things, don’t they, and crafters? They make wooly hats and corn dollies! Continue reading “Art, Craft, Make, Hack, Whatever” →

Joule Thief Steals In Favor Of Christmas

December 22, 2017 by 14 Comments

A lot of things tend to get stretched during the holiday season, like shopping budgets and waistbands and patience. This year, [Chris] is stretching the limits of both the mini breadboard and the humble 1.5 V LR44 coin cell with his joule thief-driven LED mini Christmas tree.

With the push of a micro momentary, the joule thief circuit squeezes enough power from an LR44 to boot an MSP430 microcontroller, which needs 1.8 V – 3.6 V. After boot, the micro takes control of the joule thief circuit and milks it whenever the voltage falls below 3.2 V. This tree may be small in stature, but it’s feature-rich. A push of the same momentary button cycles through four different light shows, ending with a medley of all four. Be dazzled after the break.

The code for this tiny tree, which features an awesome ASCII breadboard layout and schematic, is up on GitHub. [Chris] has it listed among a few other manageable bare-metal ‘430 projects that would be great for beginners at pure C. If that sounds like you, why not give yourself the gift of learning a new language?

We’ve seen some spirited ways of lighting LEDs, but doing it with candle power takes the fruitcake.

Continue reading “Joule Thief Steals In Favor Of Christmas” →

Coin Cells: The Mythical Milliamp-Hour

December 22, 2017 by 16 Comments

Just how much metaphorical juice is in a coin cell battery? It turns out that this seemingly simple question is impossible to answer — at least without a lot of additional information. The problem is that the total usable energy in a battery depends on how you try to get that energy out, and that is especially true of coin cells.

Energizer specs its 2032s at 0.2 mA

For instance, ask any manufacturer of the common 3 V lithium 2032 batteries, and they’ll tell you that it’s got 230 mAh. That figure is essentially constant across brands and across individual cells, and if you pull a constant 0.2 mA from the battery, at room temperature and pressure, you’ll get a bit more than the expected 1,150 hours before it dips below the arbitrary voltage threshold of 2.0 V. Just as it says on the tin.

What if you want to do anything else with a coin cell? Run an LED for a decade? Pull all the energy out right now and attempt to start a car? We had these sorts of extreme antics in mind when we created the Coin Cell Challenge, but even if you just want to do something mundane like run a low-power radio sensor node for more than a day, you’re going to need to learn something about the way coin cells behave in the real world. And to do that, you’re going to need to get beyond the milliamp hour rating. Let’s see how deep this rabbit hole goes.

Continue reading “Coin Cells: The Mythical Milliamp-Hour” →

Improving Cheap Laser Engravers For PCB Fabrication

December 22, 2017 by 24 Comments

A few months ago, [Marco] picked up a cheap, cheap, cheap laser engraver from one of the familiar Chinese resellers. It’s a simple affair with aluminum extrusions, a diode laser, and a control board that seems like it was taken from a 3D printer controller designed five years ago. Now, [Marko] is building some upgrades for this engraver and his PCB production skills have gone through the roof.

The laser engraver [Marko] picked up is called the EleksMaker, and lucky for him there are quite a few upgrades available on Thingiverse. He found two 3D printable parts, one that keeps the belt parallel to the aluminum extrusion, and another that provides adjustable x-axis tightness on the belt. With these two mods combined, [Marko] actually has a nice, smooth motion platform that’s more precise and makes better engravings.

These upgrades weren’t all 3D-printable; [Marko] also got his hands on a few Trinamic TMC2130 stepper motor drivers. These stepper drivers are the new hotness in 3D printing and other desktop CNC machines, and looking at the waveform in an oscilloscope, it’s easy to see why. These drivers produce a perfectly smooth waveform via interpreted microstepping, and they’re almost silent in operation. That’s terrible if you want to build a CNC chiptune player, but great if you want smooth engraving on a piece of copper clad board.

This project has come a long way since the last time we took a look at it a few months ago, and the results just keep getting better. [Marko] is making real PCBs with a laser engraver that cost less than $200, and the upgrades he’s already put into it don’t add up to much, either. You can take a look at [Marko]’s progress in the video below.

Thanks [dechemist] for the tip.

Continue reading “Improving Cheap Laser Engravers For PCB Fabrication” →