Ghostbusters Toaster—A Solenoid Lesson

With the help of some solenoids, the Dancing Ghostbusters Toaster really topped off my Halloween costume this year!

Although I can't speak for the most recent reboot, the original films are classics. With all the recent hype, I figured what better Halloween costume than a Ghostbuster! Of course, it was pure instinct to take it a bit too far, so I built the Dancing Toaster from the 1989 sequel!

Why?

When I thought of the idea for the Dancing Toaster, I figured what better way to teach viewers at home what a solenoid is and the proper use of one!

For this project, I used several solenoids, triggered at various times, to get my toaster groovin'. Although an Arduino was used, it really only contained simple code for triggering the solenoids. Most of the work was done by my strong power supply and the Adafruit motor-drive shield, which (as you can see in the video) is handy for driving solenoids as well.

With proper care, this could have been an analog project with individual buttons for each of the solenoids. Then you and your friends could see who could get it to flip over first! (Flip The Toaster™©.). The Arduino simply gave us more flexibility without the inconvenience of continuously hitting different buttons.

A simple push-pull solenoid!

How?

Some of my previous material has taught you how to use an Arduino, so for this project we're skipping right to the nitty gritty.

Solenoids are electromagnetic devices and are the driving force behind the toaster's dancing. When voltage is applied to the solenoid's winding, a magnetic field is generated. Solenoids are designed to concentrate this magnetic field along the interior of the winding, which is why the plunger forcefully moves when you apply voltage.

The solenoids used with the toaster are designed for 12V, and to ensure that we have plenty of power available for the solenoids, I used a hefty (8.5 amp) power supply. The Adafruit motor shield contains the high-current drive circuits that deliver power to the solenoids.

Driving a solenoid is not much different from driving a motor, so it's no surprise that the motor shield works just fine as a solenoid controller. The 12V supply is connected to the motor shield and the Arduino can be powered from a separate USB port or from the DC barrel jack—just as long as the "VIN Jumper" on the motor shield is not connected. All I had to do was plug each of the solenoids into an M-port on the shield, which can drive up to four separate DC motors (or solenoids).

The multipurpose Adafruit motor shield!

To get the toaster to jump around, I searched for the smallest and lightest toaster I could find, regardless of color (although the film's toaster is silver). The less weight my solenoids have to fight against, the better the dance moves! I hastily threw this prop together using 5-minute Gorilla Epoxy but you can do better than I did!

To save money on parts, I usually search through local second-hand stores for cheap, abandoned toys, props, and components. The toaster was only $1.60. Choosing a lightweight toaster and fairly strong solenoids ensured that I could get the toaster moving. I found a toaster with flat, metal interior walls, and an easy-to-remove bottom tray, making installation and ease-of-access a cinch.

The Arduino code is straightforward and just turns individual solenoids on and off at different times. Attach some solenoids to your mom's favorite toaster and play around with the code to see which combination of solenoid triggers gets your toaster jumping the most!
Solenoids are quite useful and sometimes overlooked. They can certainly do more than just bring a toaster to life.

By choosing the right type of solenoid, you can pull or push a mechanical load. Solenoids are found in various everyday machines and mechanisms: car door locks, automated air and water valves, mechanical doorbells, dialysis machines, etc.

Pull-type vs. push-type solenoids. For more information on solenoids and how to use them, check out this article.

How are you going to use your solenoid?

My love for solenoids lifts me higher, and lifts my toaster higher too! While the toaster is a pretty ridiculous design, you can take the knowledge you now have and implement your own design! Maybe you can even incorporate a solenoid into your Halloween costume! And if your toaster starts moving on its own without the help of electronics, who ya gonna call!?

Other MIT-i Innovations:

• The Cat-Apult! (an Arduino-controlled servo for makers)
• The Launchpad-Based Laser Tripwire Alarm! (a Launchpad security system)
• The Arduino UNIVERSAL Remote Control! (an IR receiver for your entire house)
• The Crop Duster Buster! (a clap-controlled odor-management system)
• The Traffic Light Controller! (an Arduino delay statement lesson)