Category Archives: Education

XL741: Principles of Operation

XL741

Our two “dis-integrated circuit” kits are the Three Fives Discrete 555 Timer, and the XL741 Discrete Op-Amp. These two kits are functional, transistor-level replicas of the original NE555 and μA741 (respectively), which are two of the most popular integrated circuits of all time.

Last year, we wrote up a detailed educational supplement for the Three Fives kit, that works through its circuit diagram and discusses its principles of operation down to the transistor level. Today, we are doing the same for the XL741 kit, and releasing an educational supplement that explains how a ‘741 op-amp IC works internally, down to its bare transistors and resistors:

XL741 Documentation (PDF)

This ability to peek inside the circuit makes the XL741 a unique educational tool. In what follows, we’ll work through the circuit diagram, discuss the theory of operation of the ‘741 op-amp, and present some opportunities for experiments and further exploration.

You can download the supplement here: XL741 Principles of Operation (1.1 MB PDF)

Additional Resources:

 

 

 

STEAM Fest 2015

I took a heap of pictures at the 2nd annual Silicon Valley STEAM Festival at the Reid Hillview Airport in San Jose today. This event brings out an eclectic mix of hobbyists, scientists, and enthusiasts showing off what they do. Below are a few of my favorite moments.

RC planes

The local RC aircraft enthusiasts not only displayed their aircraft, but also put on an airshow. They also fly at Baylands Park, and encouraged coming to see them on Sundays.

Huey

Vintage aircraft flew in to be displayed.

Leopard shark

Local science institutions brought their mobile displays, including leopard sharks from the Marine Science Institute.

Firebots outreach

Robotics teams, (including our very own Firebots) were demonstrating their robots in the midst of cars on display. You can find more robots, aircraft, automobiles and sharks in my album here.

A visit from the LEGOJeep

Lego Jeep at Evil Mad Scientist
Photo by Kevin Mathieu

We had a visit from one of our favorite art cars, the LEGOJeep. Our friend Kevin stopped by to work on some parts to infuse even more LEGO spirit into the Jeep.

Lasering Parts for the Jeep
Photo by Kevin Mathieu

We also had a couple of young visitors stop by to see what we were up to. Above, learning to use the laser cutter and calipers.

Lego Jeep

Very proud of her contribution to the LEGOJeep!

 

 

Build It Yourself Science on the Make Blog

Book excerpt on Polarized Light Filters

The Make Blog is featuring some excerpts from The Annotated Build It Yourself Science Laboratory.

In modern times, our contemporary Maker and Maker education movements have helped to rekindle our cultural interest in hands-on education, especially in the STEM and STEAM fields, in a way that hasn’t been seen since the 1960s — which is why it’s such a good time to bring this book back.

STEM at the White House Easter Egg Roll

Families gather around to learn more about how the EggBot works

From the White House Office of Science and Technology Policy blog post, An Egg-straordinary Day of Science and Technology:

Interacting with EggBot, an art robot that can paint very intricate and precise designs on eggs. EggBot taught students about digital design, computer numerically controlled machines and robotics. This was also a fun way to celebrate National Robotics Week!

Fall in Love with Science in Texas

The Hill Country Science Mill is celebrating its grand opening on February 14th. It’s a new science center in Johnson City, Texas housed in a historic feed mill built in 1880 as a steam grist mill and cotton gin. This picture of their WaterColorBot is from a preview day in November. A “Fall in Love with Science” event sounds like a great way to celebrate Valentine’s Day!

How to Pick a Project

Carlyn Maw’s How to Pick a DIY Electronics Project is so much more than that! It is an excellent tool for planning for just about any project. It covers thinking about project scope, tools, skills, parts and more.

Many of the questions are phrased for electronics, but most of them are applicable no matter what project you’re thinking about. And even if you have already picked a project, you can use the questions as guidelines for ways forward and to illuminate possible stumbling blocks.

We often get asked about what project to pick, and I’m glad to have this thoughtful tool to share.

Fixing on the fly at Maker Faire

Maker Faire can be a pretty demanding environment for a project. Outdoor locations expose many projects to the weather, prototypes may have been unpacked and repacked by the TSA, and curious visitors may handle projects in new and unexpected ways. Or maybe ambitions were greater than preparation time, and the project just didn’t quite get finished before the fair opened. No matter what the reason, Maker Faire is a great place to see people in action fixing, troubleshooting, and finishing their projects. Below are some beautiful projects I caught in progress at Maker Faire New York.

Pick n place

The FirePick Delta pick and place machine was a victim of the TSA, and arrived less functional than when it had been packed. The team was working on it valiantly, which also provided opportunities to get a closer look at many of the components.

Pick n place

Components not in use were repurposed for holding down business cards in the breezy aisle of 3D village.

Fixing robotic soccer

The maker of this robot arm soccer game was opening up one of the control boxes to check on a malfunctioning knob.

Robotic soccer (after repair)

He had no shortage of willing testers after the repair.

Tiny 3D printer under repair

This half-scale 3D printer assembly was at least as charming in its disassembled state as it would have been all put together. It is great to see the components along with the kinds of tools that are used to assemble and repair projects like this one.

Gertie the jumping robot

Gertie the robot had seen quite a bit of action, first at the Bay Area Maker Faire and then in New York. Her actuators were apart and in the middle of repair when we came by.

Gertie the jumping robot

This let Alonso show us the mechanism and demonstrate how the internal frame worked to lean and make Gertie jump in different directions.

Maker Faire exhibitors are generous with sharing tools and materials with each other, and visitors are treated to what are typically hidden activities. No one whisks away a broken prototype to hide it out of sight. Instead, the guts are happily spilled out for everyone to see and learn from.

Making Makers Book

AnnMarie Thomas has just released her book Making Makers: Kids, Tools, and the Future of Innovation. She interviewed many notable makers for this book, including Dean Kamen, Leah Buechley, Luz Rivas, and Nathan Seidle. I’m thrilled to be included in this group of fascinating people. It is available through Amazon for Kindle now, and paper copies are shipping September 25.