Edgerton, A High-Speed LED Flash #DIY

2019-07-25 – The list price of the well-designed Vela One has recently dropped.  I originally quoted it at about $1,750 CAD but unfortunately don’t have any proof.  As of today, the Vela website indicates it is exactly $1,526.70 CAD. The archive.org website shows that the price has indeed fluctuated over time.

2019-08-01 – A big THANK YOU to NQTRONIX who has kindly gifted me an active light probe of his own design.  The probe will be used with an oscilloscope to measure the flash duration, trigger response time, light output -v- current, and other helpful things.  I will update this post with the data once testing commences.  NQTRONIX put a TON of time into designing, testing, and optomizing his probe.  Please consider checking out his instructable page and leaving him a like or comment!

2020-03-20 – Main control boards are available at https://www.tindie.com/products/19592/.


EDGERTON

Named in honour of the legendary Papa Flash.

Some time ago I designed and built a ballistic chronograph and used it to take some high-speed photos of bullets striking glass. The results were great, but the photos were somewhat limited by the standard ‘speedlight’ flashes that I used – there was always some motion blur. Edgerton is a ‘High-Speed Flash’ which uses LED’s to make one-microsecond flashes to freeze motion.

Read moreEdgerton, A High-Speed LED Flash #DIY

Simple Sonic Anemometer #DIY

DIY Sonic Anomemoter

Measuring Air Flow – Made Easy

A sonic anemometer is a device that measures air velocity using sound. A speaker on one end of the device emits a ‘ping’, and a sensor waits for the ping to arrive. If the air is not moving, then the delay between ‘pinging’ and ‘receiving’ is always the same (kinda).

If the air is moving from the sensor toward the emitter, then the delay gets longer since the ping is traveling upstream. Conversely, if the air is moving from the emitter toward the sensor, then the delay gets shorter since the ping is traveling downstream.

I built this anemometer to measure airflow rates of various small fans.

Ingredients

All you need is an Arduino, an HC-SR04 ultrasonic distance sensor, a piece of 3/4″ PVC conduit, and a 3D printer. The 3D print file and firmware is available on Github.

3D Printed Sonic Anemometer

Read moreSimple Sonic Anemometer #DIY

PCB Jig + Lab Power Supply #DIY

I recently added a couple home-build devices to my home lab. The first is a well-designed PCB jig engineered by an electronics forensic expert. The second is a very cheap lab power supply using a Chinese step-down converter and an old battery charger.

The Jig

It seems I never have enough hands, especially while testing and troubleshooting a fresh PCB. As frustration was mounting recently, Thingiverse member Giufini seemingly heard my prayers – and shared his design for a PCB probe jig!

Thingiverse photo

At first glance, it looks somewhat hap-hazard. I built one, and must say that it is very well designed! The layout of the board is perfect for the PCB’s I work with. The towers and arms are easy to adjust and have a well-tuned flexibility to them. Finally, the acupuncture needles were simply genius! This design was even reviewed (and quite well received) on Superhouse.

PCB Probing Jig DIY

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500W Spindle Controller – Fixed!

You Get What You Pay For

While building my CNC mill, I bought a 500W spindle with a motor controller off eBay for less than $80 CAD.  The spindle and power supply needed some TLC right out of the box, but seemed to work fine.

Image From eBay of 500W Spindle & Controller

Then the incident happened… I was adjusting the ‘MAX’ potentiometer when suddenly the motor speed dropped to 5,000 RPM and wouldn’t increase!  I may have accidentally shorted the potentiometer with my screwdriver, but that shouldn’t have caused a problem.  This potentiometer is basically shorted to 0 ohms at one end anyways.

No adjustments to any of the potentiometers would change the motor speed more than a few hundred RPM.  I considered buying a replacement controller, but for $50 CAD I decided to have a crack at repairing this unit.  I ended up writing an almost-complete schematic of the controller and determining what one of the three IC’s are.

Schematic for 500W Spindle Controller / Power Supply

Read more500W Spindle Controller – Fixed!

High-Speed LED Pulsing Experiments

This page is currently being populated with past experiment data.  All future experiments will be added shortly after their completion.

The plans for Edgerton are available for anyone to build their own high-speed flash.  I designed the flash by building a prototype and doing lots of testing.  Until now, I haven’t kept an updated log of all the experiments performed on the LED’s.  Maybe some people would like to see all the details behind the designing and prototyping of the flash.  Others may be interested in designing their own high-speed LED flash.

The complete experiment logs can be found at github.com.

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Cheap Spindles & Power Fluctuations

While building my CNC mini-mill, I purchased a 500W air-cooled spindle from eBay.  It came with a power supply, which looked great and I (falsely) assumed it would work perfectly on my home-built mill.

Boy was I wrong!  The mill worked great as long as the spindle was turned off.  Whenever the spindle was on, there was a chance that the mill’s microcontroller would reset (bad), lock up (worse), or would suddenly enter an infinite loop (really really bad!) and an axis motor would begin moving in some direction until I noticed and stopped it.

After much work identifying and rectifying the causes, the power supply has finally been tamed.  Here’s a guide for anyone having the same issues.

Read moreCheap Spindles & Power Fluctuations

Cheap Trigger for High-Speed Photography

A simple trigger for high-speed photography is the ‘tripwire’ trigger.  Unfortunately few (if any) commercially available flashes are configured for this trigger.  Thankfully, an Arduino-based trigger controller is very easy to make.  I will also shamelessly plug Edgerton, an open-source LED flash specifically designed for high-speed photography, that can be tripwire-triggered without any major hardware!

How It Works:

A small bracket must be built for the muzzle of your rifle (or whatever you are using).  Two pins protrude from the end of the bracket and a fine wire is wrapped between the pins.  The pins are connected to a port (I use a 3.5mm audio port) which can be connected to Edgerton or the trigger controller by an extension cable.

When the projectile exits the muzzle, it passes through the wire and breaks it.  The two pins, which were once connected by the wire, are now ‘open’.  Edgerton or the flash controller detects that the pins are separated and a timer is started.  After the timer finishes, the flash is triggered.

Read moreCheap Trigger for High-Speed Photography

H-alpha Imaging On The Cheap

This post is incomplete, but I hoped to begin sharing my tools and experience so others could hopefully benifit.

I’ve been stunned by some Hydrogen-Alpha (Ha) astrophotos.  Particularly when they’re combined with visible light photos (HaRGB and some other ways) the depth is stunning!

Unfortunately my astrophotography budget has been spent for the forseeable future.  This is my attempt to capture those photos using the following equipment:

  • Canon 1200D (T5) DSLR
  • 80mm Refractor Telescope and its infrastructure
  • Optolong 7nm Ha 2″ filter

Read moreH-alpha Imaging On The Cheap

Automating GIMP

Let me be clear about something.  GIMP is probably my favourite piece of open-source software.  Truth told, I could have a license for Photoshop or PaintShopPro, and I would still use GIMP.  That’s because it is so focused on functionality over style – which means that, despite its limited development (it’s open-source after all), it is a program that has the horsepower to compete with the big players.  All you have to do is learn its quirky UI!

Read moreAutomating GIMP