Time Delay Relay

Time Delay Relay

I’m working on a project that requires two power strips to be turned on in a sequence. The first power strip powers 6 HDMI displays, and the second one powers 6 computers. The displays have to be on before the computers so they sync properly and get the correct resolution. Since I can’t rely on a person to do this properly, automation is the answer.

My first thought was to use something like a PowerSwitch Tail with a microcontroller to trigger it. (There’s also a cheaper kit version available.) The issue with this solution is that I’d need a microcontroller, and a power supply for the microcontroller, which are more parts, and more points of failure, and take up more space. I also considered using a cheap relay module, but ultimately I was overly complicating the whole thing. Also, I want this to be reliable, and sticking a 5v power supply, a microcontroller, and a relay in a box for three years seemed a little risky.

What I really needed was a “Time Delay Relay” which is a device that can get power, wait X number of seconds, and then power on another thing. There’s a whole bunch of them you can just buy! Time Delay Relays are not cheap though… This one is under $40, but you’ll probably also want the socket, which puts you closer to $50.

Luckily, Milwaukee Makerspace is filled with all sorts of old industrial “junk” and we have a bunch of these sitting on a shelf! Brant (you know, the guy who made a Auto-Off Timed Outlets from an old microwave control panel) helped me find one and get it wired up last week. It works great!

I used a $3 extension cord to provide an easy way to plug it into the first power strip and plug the second power strip into it. There’s a dial that lets you set the delay up to 10 seconds, which is more than enough for my needs.

Time Delay Relay

If I’ve learned anything from this project it’s that even though you think you might have a good solution to a problem, it’s still worth asking others (at the space or on the mailing list) because you may get a better solution, and may even get the parts you need.

Let’s Detonate!

Dan Loves Fire!

Dan loves fire! It’s a fact! For Maker Faire Milwaukee we made a fire poofer which was triggered by pressing a button. Tons of kids (and adults) pressed that button over the course of the weekend.

While Dan the Blacksmith (and John McGeen from BBCM) were the primary builders of the fire poofer, I did the trigger electronics and enclosure.

The Detonator

I’ve written up a blog post with lots of images explaining the (somewhat rushed) build of the device. It’s Arduino powered, has some relays and a beeper, and looks semi-nefarious. Read more about The Detonator.

The Detonator Insides

Ben will be “Looping the Lake” electrically!

Ben Nelson

Ben Nelson may be just a little bit obsessed with electric vehicles. Over the years he’s built an electric car and electric motorcycle, and he’s even got an electric riding lawnmower. He wanted to show the power of electric vehicles, so he decided to have his own “DIY Road Rally” and ride his Vetrix all the way around Lake Michigan.

Chargers

All way way around the lake!? That’s 1,000 miles with no gasoline. He’ll be charging up a lot, but he knows where, when, and how to charge up.

Charging

People often say that electric vehicles are only good for short trips around the city, but Ben aims to prove them wrong. He’s also planning a full-length documentary film about his adventure…

Charging

Ben will also be appearing at Maker Faire Milwaukee in a few weeks, and he’ll be sharing what he learned on his trip. If you want to keep up-to-date while he’s out there, check out his blog or follow the journey on Facebook.

Loop the Lake

Here’s a short video of Ben driving away from Milwaukee Makerspace, on his way around Lake Michigan. Good Luck, and see you soon, Ben!