Making an Inductor Saturation Current Tester

inductor saturation tester

[Kalle] tipped us about a quick project he made over a couple of evenings: an inductor saturation current tester. All the components used for it were salvaged from a beefy telecom power supply, which allows the tester to run currents up to 100A during 30us in the inductors to be characterized.

Knowing the limits of an inductor is very convenient when designing Switch Mode Power Supplies (SMPS) as an inadequate choice may result in very poor performances under high loads. [Kalle]‘s tester simply consists in a N-Mosfet switching power through a load while a shunt allows current measurements. The saturation point is then found when the current going through the inductor suddenly peaks. As you can see from the picture above, 16 4700uF electrolytic caps are used to compensate for the sudden voltage drop when the Mosfet is activated. A video of the system in action is embedded after the break.

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Bluetooth Thingies at Maker Faire

In case you haven’t noticed, one of the more popular themes for new dev boards is Bluetooth. Slap a Bluetooth 4.0 module on a board, and you really have something: just about every phone out there has it, and the Low Energy label is great for battery-powered Internets of Things.

Most of these boards fall a little short. It’s one thing to throw a Bluetooth module on a board, but building the software to interact with this board is another matter entirely. Revealing Hour Creations is bucking that trend with their Tah board. Basically, it’s your standard Arduino compatible board with a btle module. What they’ve done is add the software for iOS and Android that makes building stuff easy.

Putting Bluetooth on a single board is one thing, but how about putting Bluetooth on everything. SAM Labs showed off their system of things at Maker Faire with LEDs, buttons, fans, motors, sensors, and just about every electrical component you can imagine.

All of these little boards come with a Bluetooth module and a battery. The software for the system is a graphical interface that allows you to draw virtual wires between everything. Connect a button to a LED in the software, and the LED will light up when the button is pressed. Move your mouse around the computer, and the button will turn on a motor when it’s pressed.

There are a few APIs that also come packaged into the programming environment – at the booth, you could open a fridge (filled with cool drinks that didn’t cost five dollars, a surprise for the faire) and it would post a tweet.

Freescale and Texas Instruments Goodies and World Maker Faire

Freescale was very kind to Hackaday at Maker Faire this weekend, showing off a few boards and answering a few questions about why old Motorola application notes aren’t available on the Internet.

The Hummingboard from SolidRun comes in an oddly familiar form factor to anyone who has ever handled a Raspberry Pi. It also has an interesting feature: the CPU is on a small module, allowing anyone to upgrade the chipset to something significantly more powerful. In the top of the line configuration, it has a two core iMX6 CPU with a Gig of RAM, LVDS output, and Gigabit Ethernet. All the complex bits for this board are on a single module, allowing anyone to take the module and put it in another project, a la the Intel Edison.

Also in the Freescale booth was the pcDuino, a dual core ARM Cortex A7 with Ethernet, WiFi, and a SATA, with Arduino form factor pinouts. It’s a somewhat niche product, but being able to stack shields on something comparable to a Raspi or BeagleBone is a nice feature.

[Trey German] from Texas Instruments showed off some very cool stuff, including a quadcopter board for a Launchpad microcontroller. This isn’t a board with an IMU and a few servo outputs; this is the whole shebang with a frame, motors, and props. The frame was cut from some odd composite that’s usually used for road signs, and even though it wasn’t flying at the Faire (nothing was flying, by the way), it’s pretty light for a quad made at a board house.

Also from TI was their CC3200 dev board. This is a single chip with an ARM Cortex M4 and a WiFi radio that we’ve seen before. The CC3200 runs TI’s Wiring/Arduino inspired development environment Energia, and at about $30 for the CC3200 Launchpad board, it’s an easy and cheap way to build an Internet of Things thing.

Experience the “Farmer’s Market” of Vintage Electronics

electronics-swap-meet-montage

Normally when you think of a Farmer’s Market, fresh produce grown nearby comes to mind. This experience was similar in that much of the produce was conceived locally, but the goal is to be anything but fresh. I had the opportunity last weekend to attend the final Electronics Flea Market of 2014. I can’t speak for everyone, but there is an obvious affinity for vintage electronics equipment in just about any condition. The people you run into are as interesting as the equipment being swapped, and the social outing tends to continue even after the swap meet closes.

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A Proof of Concept Project for the ESP8266

weather

It’s hardly been a month since we first heard of the impossibly cheap WiFi adapter for micros, the ESP8266. Since then orders have slowly been flowing out of ports in China and onto the workbenches of tinkerers around the world. Finally, we have a working project using this module. It might only be a display to show the current weather conditions, but it’s a start, and only a hint of what this module can do.

Since the ESP8266 found its way into the storefronts of the usual distributors, a lot of effort has gone into translating the datasheets both on hackaday.io and the nurdspace wiki. The module does respond to simple AT commands, and with the right bit of code it’s possible to pull a few bits of data off of the Internet.

The code requests data from openweathermap.org and displays the current temperature, pressure, and humidity on a small TFT display. The entire thing is powered by just an Arduino, so for anyone wanting a cheap way to put an Arduino project on the Internet, there ‘ya go.

Build Your Own Retrocomputer with Modern Chips

F2J850II00TI11R.LARGE

If you’ve ever wanted to get started in retrocomputing, or maybe the Commodore 64 you’ve been using since the 80s just gave up the ghost, [Rick] aka [Mindrobots] has just the thing for you: a retrocomputer based on a PIC microcontroller and a Parallax Propeller.

The two chips at the heart of the computer are both open source. The Propeller is the perfect board to take care of the I/O, video, and audio outputs because it was purpose-built to be a multitasking machine. The microcontroller is either a PIC32MX150 or a PIC32MX170 and is loaded with a BASIC interpreter, 19 I/O pins, a full-screen editor, and a number of communications protocols. In short, everything you would ever want out of a retro-style minicomputer.

The whole computer can be assembled on a PCB with all the outputs you can imagine (VGA, PS/2, etc) and, once complete, can be programmed to run any program imaginable including games. And, of course, it can act as a link to any physical devices with all of its I/O because its heart is a microcontroller.

Retrocomputing is quite an active arena for hackers, with some being made from FPGAs and other barebones computers being made on only three chips. It’s good to see another great computer in the lineup, especially one that uses open chips like the Propeller and the PIC.

Afroman Demonstrates Boost Converters

boosIf you need to regulate your power input down to a reasonable voltage for a project, you reach for a switching regulator, or failing that, an inefficient linear regulator. What if you need to boost the voltage inside a project? It’s boost converter time, and Afrotechmods is here to show you how they work.

In its simplest form, a boost converter can be built from only an inductor, a diode, a capacitor, and a transistor. By switching the transistor on and off with varying duty cycles, energy is stored in the inductor, and then sent straight to the capacitor. Calculating the values for the duty cycle, frequency, inductor, and the other various parts of a boost converter means a whole bunch of math, but following the recommended layout in the datasheets for boost and switching converters is generally good enough.

boostconverter

[Afroman]‘s example circuit for this tutorial is a simple boost converter built around an LT1370 switching regulator. In addition to that there’s also a small regulator, diode, a few big caps and resistors, and a pot for the feedback pin. This is all you need to build a simple boost converter, and the pot tied to the feedback pin varies the duty cycle of the regulator, changing the output voltage.

It’s an extremely efficient way to boost voltage, measured by [Afroman] at over 80%. It’s also exceptionally easy to build, with just a handful of parts soldered directly onto a piece of perfboard.

Video below.

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