VFD Filament Driver Circuit

Don't give up! I spent the last 3 years troubleshooting this circuit with an LM4871 chip with the goal of supplying a low voltage alternating square wave current across the filament of vacuum fluorescent displays. Spoiler alert: it was the addition of a single 10Ω resistor to lower the voltage from ~5V down to ~3.3V.

Learning to Solder Technique

I've been teaching middle schoolers to solder for years but I only came up with this approach to the workflow this year and it has been a game changer.

Arduino Controlled 5V Relay for Christmas Tree Lights

Our christmas tree lights plug into the wall behind the tree and are always hard to reach without sprinkling needles on the floor when we want to turn the lights on or off. This year I made an Arduino controlled relay that can turn the lights on and off with a switch that extends out next to the tree. Here is a video of the switch in action:

Hacking Salvaged LED Displays (Part II)

Good news! I just found a discarded VCR with an LED display. That means it's time to salvage the display and make a project out of it. While the last post on 7-segment displays was a single digit, standard display, this one actually turns out to be 10-segment with non-numerical segments. So it will be an exercise in figuring out how a non-standard display works. In this post I will go over my process for hacking a display like this. If you're interested in doing this for a simple, standard 7-segment numerical display see this other post.

Teensy-Controlled Vacuum Fluorescent Display: Step-by-step

I'm recording in pictures the steps I'm taking to power and control this Yamaha Futaba vfd I removed from an old entertainment system.

Several Vacuum Fluorescent Displays

I have found, scavenged, and lit up four vacuum fluorescent display now, and look forward to many more. I find them beautiful both in the quality of their light and the complexity and fragile appearance of their circuitry.

Vacuum Fluorescent Display Adventures

I found an old 1986 microwave up the street to take apart. My favorite part to salvage from microwaves is the turntable motor but this one had a very special numerical display. I could see it wasn't your usual LED display but is encased in glass and filled with interesting metal plates and fine filaments.

Summer PD In Electronics

This summer I did some self-guided PD in basic electronics guided by my son's interest in learning about it. It has been a wonderful thing to do together, plus I've learned a ton. I probably would have covered what we did this summer in one week in Electronics 101 in college but the time has given us the opportunity to really let things sink in and follow up on our own questions. Here is the website that guided our experiments. This All About Circuits textbook written by Tony R. Kuphaldt explains things well but most importantly asks the learner to find their own resources for the experiments, which has been one of the most enlightening parts of the experience. Below I outline our activities and learnings, and some reflections.

Makerspace Project: LED Side-lit Acrylic Signs

One of my favorite projects over the last couple years to do in our maker-space classroom is side-lit acrylic signs. The project has evolved a bit as I have improved the design of the signs and workflow for students and it is now in a place I really like.