by ASCAS @ instructables.com:
Have you ever wanted to broadcast your own radio station within the neighborhood? Ever get curious on where people get those “Surveillance Bugs” from spy and action movies? This small and simple FM transmitter is the toy that geeks have always wanted.
FM transmitters can be complicated to build, that’s why I’m teaching you how to make a foolproof FM transmitter. There’s no need to buy kits, this tutorial includes the PCB layout and the schematics. It has a range of up to 1/4 mile or more. It’s great for room monitoring, baby listening and nature research.
The Ultimate FM Transmitter (Long Range Spybug) - [Link]
When you start hooking peripherals such as keyboard, WiFi dongle and mouse to a Raspberry Pi it’s not long before you run out of ports and need a USB hub, preferably powered so that it can supply the RPi as well. At this point cabling starts to take over your workspace.
The Raspiado board, launched on Kickstarter should help cut down on the tangle; it has the same dimensions as the RPi board and mounts on its underside via two (stackable) standoff pillars to leave the top GPIO and camera connectors open to whatever you’re building so that it won’t impede the RPi’s connectivity options.
Raspberry Pi without the Spaghetti - [Link]
by BasinStreetDesign @ instructables.com:
I had a bunch of random inductors in some random drawers and I wanted to know what values they were. These values are quite often not obvious by looking at the device. Colour codes for old ones were not standardized and some of the coloured rings on inductors can be faded or discoloured so that its impossible to tell what they are. Others may be unmarked and any that are hand-wound are just guess work without a meter. So I decided to make an inductance and capacitance meter which would be fairly accurate and work over several decades of value from a few nano-Henries to a few milli-Henries and also from a few pico-farads to about a micro-farad (hopefully). Sounded easy – what could go wrong?
Inductance/Capacitance Meter Saga - [Link]
Programmable DC, AC, current- and high-voltage power supplies, electronic loads, UPS, inverters and chargers of small and high power suitable for production and servicing – this is Elektro Automatik.
When we establish a production or testing workplace, we usually can´t omit a suitable power supply. Sometimes a „universal“ like 2x30V/3A is sufficient, but often not. It´s well known fact for those of you, who produce devices various devices requiring higher current or higher voltage. Typical representatives are equipment for automotive industry, various drives, backup sources, solar devices etc. In these case tens to hundreds Amps and/or hundreds to thousands of Volts are no rarity.
Right for these purposes, German company Elektro Automatik produces devices and systems for power supply and simulation of conditions in a real operation. Adjustable DC and AC power supplies, current sources, electronic loads and other devices can serve for a thorough examination of your devices even in “border conditions” and they can help to discover eventual hidden faults which might occur later in a real operation. Many Elektro Automatik products are programmable and they´re also connectable to some of common buses like CANopen, Profibus, ProfiNet, DeviceNet, Modbus, Ethernet and also RS232. Also interesting are for example electronic loads with energy recovery, where the lost energy doesn´t transform to heat but returns back to mains line with efficiency of about 93%.
Upon request, we´re able to provide you with any product from the Electro Automatik catalogue (14,5 MB).
Where common power supplies end, there the Elektro Automatik begins - [Link]
by Annikken @ instructables.com:
This waveform generator is based on the work by Amanda Ghassaei. Waveform generators (or function generators) are used for testing and debugging circuits. e.g. frequency response of op amp or sensors. This waveform generator is powered by Arduino with Annikken Andee shield – a device that lets users create iOS/Android interfaces without iOS or Android programming at all. It outputs sine, triangle, saw and square waves. Frequency is controlled by means of a slider (on iOS/Android device) and wave type is selected using on screen iOS/Android button. With a iOS/Android interface, you can add certain features not possible with hardware buttons. E.g. displaying different ranges of frequencies for each wave type, displaying meaningful controls for certain wave types. For example, the pulse width modulation slider is only visible for square wave types, its not visible for sine, triangle or saw wave forms.
IOS-Controlled Arduino waveform generator - [Link]
by intensePancake @ instructables.com:
In recent years, portable sensor devices have gained a lot of popularity due to their ability to give you instant, accurate information about your local environment. Some of these devices include the Sensordrone, Smart Citizen, and the Storm Tag. These devices combine portability and accessibility in such a way that they’re easy to use and convenient to carry around. However, they can be expensive, as they’re required to pack quite a bit of advanced technology into a very small package.
This Instructable is for my Bluetooth Low Energy Go-Anywhere Sensor Pack (BLEGASP, if you will). It’s a device that I built from an Arduino and various environment sensors. Since environmental concerns differ from person to person, I wanted to create a device that maximizes sensor modularity.
Bluetooth LE Go-Anywhere Sensor Pack - [Link]
Graphic showing the GPIO pin breakout on the Raspberry Pi B+ board.
Raspberry Pi B+ GPIO 40 Pin Block Pinout - [Link]
JColvin91 @ instructables.com writes:
I recently got a collection of soldering iron tips and realized that many people (including myself) might not know what the different tips are used for. After all, for a long time I was under the impression that there was only about three different types of soldering tips and only one useful type of tip.
While I still only use two different types of tips (an improvement), I am much more familiar and confident in using whatever soldering iron tip I may happen to find on the iron. Please know that is far from a comprehensive list of all the different types of soldering tips available, but rather a small handful that I am personally prone to use.
Uses of Different Soldering Iron Tips - [Link]
By Ben Coxworth @ gizmag.com:
Ever since the Fukushima nuclear reactor disaster, there has understandably been an upsurge in the sale of consumer radiation-detecting devices. Most of these gadgets are variations on the Geiger counter, in that they alert the user to the presence and level of radiation, but not the type of radiation – which is very important to know. Researchers at Oregon State University are hoping to address that situation, with the MiniSpec. Currently in development, the handheld device will additionally tell its users what type of radionuclide is creating the radiation, and whether it poses a risk.
Small, portable and cheap radiation detector is being designed for the public - [Link]
by sajjad Haidar @ edn.com:
Power supplies with adjustable DC output ranging from 0V to 30V or 60V are on the market. Above 60V, there are not many. This Design Idea offers a solution.
There are many fixed voltage switching mode power supplies (SMPS) available, and connecting several in series can give us a higher fixed voltage. To obtain an adjustable output either from a SMPS or conventional transformer based supply, one needs to use a linear regulator or a switched mode buck converter. For a buck converter, a MOSFET or an IGBT can be used as a switching element.
Usually, for a high side switch, an IC with bootsrap operation or a pulse transformer is used. There are few photovoltaic couplers available to drive MOSFETs. As they do not provide much current to charge the gate capacitance quickly, these photovoltaic couplers are mainly used to drive low frequency MOSFET switches, such as solid state relays.
Variable HV power supply employs photovoltaic optocoupler - [Link]