[Hack a Day] 3 New Entries: Working with relays

Working with relays

SparkFun’s latest tutorial shows you how to work with relays. A relay is an electrically operated switch. In this case, they’re using it to switch a 120V AC outlet. The article carries the standard warnings about how not to kill yourself with AC (plus some non sequitor linking throughout). As an extra precaution, they chose a GFI outlet. You probably know how a relay works, but it’s worth seeing how they implemented it. They use a transistor to prevent overloading the microcontroller’s GPIO pin. The control pin is pulled to ground to keep the relay off. A diode is placed across the relay coil to manage the power flow when it discharges. An indicator LED is included to show when the relay closes. This is a great foundation for an automation project, or maybe you just want to terrorize your cat.

      

Ripsaw MS1

The Ripsaw MS1 is an unmanned ground vehicle built by two brothers in Maine. The tracked vehicle can go 0-60 in 3.5 seconds with an 80mph top speed. In its current form, it has a 2000 pound capacity, which opens the possibility for many different types of weapon systems. Control is provided by two people: one driver and one gunner. They work in independent remote stations. The Ripsaw could potentially be used in any application normally reserved for a tank. It could lead a charge without putting soldiers at risk.

We’ve been watching this project mature since 2005 when it was being marketed as a Grand Challenge competitor. This week it’s being demoed at the Army Science Conference. Check out footage of it in motion below.

[via BotJunkie]

      

Arduino switch box

When you’re prototyping a new project, sometimes all you need is a switch. The folks at oomlout were tired of constantly having to rewire things, so they built a universal switch box for the Arduino. It has five potentiometers plus three switches. They’ve put together a software package that monitors the switches and can show you a live view of the knob positions. Have a look at the video below for a demo.

The writeup actually hints at what we can only assume is the next kit they’re releasing: a robot arm.

      

You received this email because you are subscribed to the real_time feed for http://hackaday.com/feed/. To change your subscription settings, please log into RSSFWD.