An Engineer Who Retires to the Garage

Jerry Brown, of Camarillo, CA, retired from the aerospace industry five years ago but continues to consult and work on numerous projects at home. For example, he plans to submit an article to Circuit Cellar about a Microchip Technology PIC-based computer display component (CDC) he designed and built for a traffic-monitoring system developed by a colleague.

Jerry Brown sits at his workbench. The black box atop the workbench is an embedded controller and is part of a traffic monitoring system he has been working on.

Jerry Brown sits at his workbench. The black box atop the workbench is an embedded controller and part of  his traffic monitoring system project.

“The traffic monitoring system is composed of a beam emitter component (BEC), a beam sensor component (BSC), and the CDC, and is intended for unmanned use on city streets, boulevards, and roadways to monitor and record the accumulative count, direction of travel, speed, and time of day for vehicles that pass by a specific location during a set time period,” he says.

Brown particularly enjoys working with PWM LED controllers. Circuit Cellar editors look forward to seeing his project article. In the meantime, he sent us the following description and pictures of the space where he conceives and executes his creative engineering ideas.

Jerry's garage-based lab.

Brown’s garage-based lab.

My workspace, which I call my “lab,” is on one side of my two-car garage and is fairly well equipped. (If you think it looks a bit messy, you should have seen it before I straightened it up for the “photo shoot.”)  

I have a good supply of passive and active electronic components, which are catalogued and, along with other parts and supplies, are stored in the cabinets and shelves alongside and above the workbench. I use the computer to write and compile software programs and to program PIC flash microcontrollers.  

The photos show the workbench and some of the instrumentation I have in the lab, including a waveform generator, a digital storage oscilloscope, a digital multimeter, a couple of power supplies, and a soldering station.  

The black box visible on top of the workbench is an embedded controller and is part of the traffic monitoring system that I have been working on.

Instruments in Jerry's lab include a waveform generator, a digital storage oscilloscope, a digital multimeter, a couple of power supplies, and a soldering station.

Instruments in Brown’s lab include a waveform generator, a digital storage oscilloscope, a digital multimeter, a couple of power supplies, and a soldering station. 

Brown has a BS in Electrical Engineering and a BS in Business Administration from California Polytechnic State University in San Luis Obispo, CA. He worked in the aerospace industry for 30 years and retired as the Principal Engineer/Manager of a Los Angeles-area aerospace company’s electrical and software design group.

High-Tech Halloween

Still contemplating Halloween ideas? Do you have a costume yet? Is your house trick-or-treat ready? Perhaps some of these high-tech costumes and decorations will help get you in the spirit.

Recent Circuit Cellar interviewee Jeremy Blum designed a creative and high-tech costume that includes 12 individually addressable LEDs, an Adafruit microcontroller, and 3-D printing.

Skull_Side_Full_IMG_0067

Custom animatronic skull

RavenSide2Armature_IMG_0015

Animatronic talking raven

Looking for Halloween decoration inspiration? Peter Montgomery designed some programmable servo animation controllers built around a Freescale Semiconductor 68HC11 microcontroller and a Parallax SX28 configurable controller.

Peter’s Windows-based plastic skull is animated with RC servos controlled via a custom system. It moves at 24 or 30 frames per second over a custom RS-485 network.
This animatronic talking raven features a machined aluminum armature and moves via RC servos. The servos are controlled by a custom system using Windows and embedded controllers.

Peter’s Halloween projects were originally featured in “Servo Animation Controller” (Circuit Cellar 188, 2006). He displays the Halloween projects every year.

Feeling inspired? Share your tech-based Halloween projects with us.

New Product: LED Drivers for Dimmable Bulbs

The iW3606 and the iW3608 are single-stage, solid-state lighting (SSL) LED drivers. The iW3606 (8-W output power) and the iW3608 (15-W output power) feature configurable over-temperature protection (OTP) and derating functionality to provide predictability and reliability of bulb operating life.

Designed for all retrofit bulbs, including candle and GU10 lamp replacements used in existing phase-cut dimmer installations, the LED drivers manage poor dimming performance (e.g., pop-on, popcorning, dead travel, drop-out, and flicker) and short bulb lifetime or failure. Both drivers meet or exceed global regulations for power quality and efficiency with less than 0.92 power factor (PF) and less than 20% total harmonic distortion (THD).

The LED drivers’ OTP and derating feature addresses the thermal issues caused by the high and unpredictable operating temperatures in dimmable SSL applications. iWatt’s OTP derating monitors the temperature inside sealed SSL bulbs. When thermal conditions reach a point set by the system designer, the LED drivers automatically reduce the current drive to the LEDs, lowering the power dissipation and resulting in a cooler overall operation.

The iW3606 and the iW3608 feature a wide, flicker-free dimming range from 100% to 1% of measured light to closely match incandescent bulbs’ dimming performance. This enables smooth “natural” dimming with no light drop-out at the low end of the dimming range and virtually no dead travel where the light turns off before the dimmer control reaches the bottom of its travel.

The LED drivers’ low internal power consumption enables them to start at less than 5% of light output, which is a very low dimming level. This virtually eliminates pop-on, in which the light does not turn on at low dimmer levels and, as the dimmer level is raised, the light suddenly turns on. The low power consumption also helps eliminate popcorning effects, in which various bulbs in multiple-light installations on the same dimmer circuit can turn on at different dimmer-setting thresholds.

The iW3606 costs $0.46 and the iW3608 costs $0.51, both in 1,000-unit quantities.

 

iWatt, Inc.

www.iwatt.com

LED Characterization: An Arduino-Based Curve Tracer

Circuit Cellar columnist Ed Nisley doesn’t want to rely solely on datasheets to understand the values of LEDs in his collection. So he built a curve tracer to measure his LEDs’ specific characteristics.

Why was he so exacting?

“Most of the time, we take small light-emitting diodes for granted: connect one in series with a suitable resistor and voltage source, it lights up, then we expect it to work forever,” he says in his July column in Circuit Cellar. “A recent project prompted me to take a closer look at commodity 5-mm LEDs, because I intended to connect them in series for better efficiency from a fixed DC supply and in parallel to simplify the switching. Rather than depend on the values found in datasheets, I built a simple Arduino-based LED Curve Tracer to measure the actual characteristics of the LEDs I intended to use.”

The Arduino Pro Micro clone in this hand-wired LED Curve Tracer controls the LED current and measures the resulting voltage.

Ed decided to share the curve tracer with his Circuit Cellar readers.

“Even though this isn’t a research-grade instrument, it can provide useful data that helps demonstrate LED operation and shows why you must pay more attention to their needs,” he says.

Ed says that although he thinks of his circuit as an “LED Curve Tracer,” it doesn’t display its data.

“Instead, I create the graphs with data files captured from the Arduino serial port and processed through Gnuplot,” he says. “One advantage of that process is that I can tailor the graphs to suit the data, rather than depend on a single graphic format. One disadvantage is that I must run a program to visualize the measurements. Feel free to add a graphics display to your LED Curve Tracer and write the code to support it!”

He adds that “any circuit attached to an Arduino should provide its own power to avoid overloading the Arduino’s on-board regulator.”

“I used a regulated 7.5 VDC wall wart for both the Arduino Pro Mini board and the LED under test, because the relatively low voltage minimized the power dissipation in the Arduino regulator,” he says. “You could use a 9 VDC or 12 VDC supply.”

To read more about Ed’s curve tracer, check out Circuit Cellar’s July issue.

 

ALTspace – Cubes, Shame and Art

ALTSpace is a Community Art Workshop in Seattle. Creative people of all kinds share this spacious workshop, teaching, experimenting, making and learning. Members can spend time bouncing ideas off one another, hold or attend classes, work away from home and have the space to get even large projects done.

Location 2318 E. Cherry Street, Seattle, WA
Members 37
Website airlighttimespace.org

ALTspace hackerspace, Seattle

Co-founder Mike tells us about his space:
Tell us about your meeting space!

We have a total of about 2800 sq ft. We have two garage spaces for industrial machines, loud and dirty operations. (about 700 sq ft total) The rest of the space is for personal workspaces and public areas for working, meeting, hanging out. We have 2 showers, 2 bathrooms, a kitchen, a laundry room and an outdoor patio.

What tools do you have in your space? (Soldering stations? Oscilloscopes? 3-D printers?)

Full list of ALTspace’s tools & equipment.

Are there any tools your group really wants or needs?

A laser cutter would be our next purchase.

Does your group work with embedded tech (Arduino, Raspberry Pi, embedded security, MCU-based designs, etc.)?

Yes, we do quite a bit of electronics. One of our more well known projects, the Groovik’s Cube (A 30ft playable Rubik’s Cube) is an arduino driven project.

Can you tell us about some of your group’s recent tech projects?

Groovik’s Cube:

ALTspace's Groovik's CubeWe first built the cube as an art project for Burning Man 2009 and we’ve since been working hard to try and bring this project to the general public. We’ve been collaborating with the Science Center since summer ’10 and we’ve been doing a number of refurbishments including a brand new light-weight aluminum structure to create a neater look suitable for an indoor museum environment.

Groovik’s cube is a fully playable, LED driven Rubik’s cube, hung from the ceiling, corner down. (the motion is of course simulated, not mechanical, i.e. the colors move around, not the structure itself). It can be played and solved by the visitors. A particularly interesting feature is that we have split the controls into 3 stations placed around the cube, each allowing only one axis of rotation. This means 3 people have to collaborate together to solve it. The stations are ~30-50 ft apart from each other. This makes the puzzle considerably harder with a current record solution time of 50 minutes (achieved on Friday night @ Burning Man 09). It also turns a very introverted game into a collaborative challenge which is fun to watch. Imagine people shouting instructions to each other and running around checking on the state of the cube from different angles.

Temple of Shame:

ALTspace's Temple of Shame

by Alissa Mortenson, Nebunele Theatre, The Temple of Shame was a 6ft wide, 18ft tall wooden Temple dedicated to the collection of shame from the participants of Black Rock City. The temple was ceremonially burned on the last night of the festival to symbolically release all the shame collected.

From shameproject.org: “The experience of shame is part of our shared humanity, yet paradoxically, the times when we are ashamed are the times when we feel most alone. But within shame lies a capacity for human connection. The Shame Bearers seek to explore this emotion as a powerful medium for reaching a state of shared vulnerability. In order to make connection –the core human desire– we must believe that we are enough, that we are worthy of love and acceptance. In our vulnerability and our recognition of our mutual imperfections, we can find worthiness and connection. That is the power of this project.”

What’s the craziest project your group or group members have completed?

Groovik’s cube for sure.

Do you have any events or initiatives you’d like to tell us about? Where can we learn more about it?

Indeed: http://lsc.org/grooviks. We’re trying to raise funding for a new Groovik’s cube that will travel the World for 7 years together with Liberty Science Center and Erno Rubik!

What would you like to say to fellow hackers out there?

Hack more! Not satified with availability of hackerspaces near you ? Start one! It’s easier than you think and people come out of the woodwork to come and help and donate time and tools.

ALTspace’s tools & equipment:

Metal:

  • 2HP Metal Mill & Lathe
  • Lincoln 220 MIG Welder (up to 1/4″ steel)
  • TIG 200Amp DC/AC (i.e. Steel, Aluminum & other non-ferrous)
  • Plasma Torch (Up to 1″ steel or aluminum)
  • Stick Welder
  • Metal Grinding wheels, belt sanders
  • 4×6 Metal Bandsaw
  • Deburring wheel and 2 buffers
  • Wire bender
  • Abrasive metal chop saw

Machine Shop (Wood):

  • 3/4HP Table saw
  • Router table & Hand Router
  • Various Sanders (Orbital & Belt)
  • Miter Chop saw

Other Machine Shop amenities:

  • 90 PSI Compressor
  • 3/4HP 1/2″ Shank Drill press
  • Hand drills, Sander
  • 110V/230V Power (50A)

Glass:

  • Glass fusing/slumping/casting kiln, up to 1600 deg F

Jewelery setup:

  • Small Propane/Oxygen torch for soldering/annealing
  • Flexshaft Rotary grinder
  • Rolling Mill
  • Disc Die Cutter & Hemisphere punch

Electronics benches:

  • Maker bot
  • Soldering station with fume extractor and static pad
  • Multimeter
  • 100 Mhz Oscilloscope (Techronix)
  • Basic tools (snippers, strippers, screwdrivers, etc)
  • Variable voltage / current power supply
  • Stock of common components
  • Anti-static worktop

Sewing Area:

  • Pfaff industrial sewing machine
  • Janome domestic sewing machine
  • Hoseki HK757G is a 5-thread industrial serger
  • White domestic 4-thread serger
  • irons, cork-topped layout table, digitizing table, pattern plotter
  • Janome Computerized domestic sewing machine
  • Rowenta domestic iron
  • Sleeve board
  • Tailor’s ham
  • Pattern Drafting Rulers and curves
  • Costuming books

Read more about ALTspace’s Groovik’s Cube project on indiegogo or on Mike’s website, or about The Shame Project on shameproject.org!

You can read about more of ALTspace’s projects on their art page.

Show us your hackerspace! Tell us about your group! Where does your group design, hack, create, program, debug, and innovate? Do you work in a 20′ × 20′ space in an old warehouse? Do you share a small space in a university lab? Do you meet at a local coffee shop or bar? What sort of electronics projects do you work on? Submit your hackerspace and we might feature you on our website!