A Modern Take on the Phenakistoscope
Introduction: A Modern Take on the Phenakistoscope
The Phenakistoscope is an early optical illusion device that uses static images to create the illusion of motion through the principle of persistence of vision. It is regarded as one of the first forms of moving media entertainment that paved the way for the motion picture industry.
We are not sure how big is the community currently interested in phenakistoscopes, however, from browsing through the internet, there seems to be quite a huge interest in this subject.
If you do not know how a phenakistoscope works, you may visit https://youtu.be/r4B3FHHt_k8 to see one in action.
It may be amazing to watch the mirror reflected images come to life by peeking through the slits or slots of phenakistoscopes, however, it can be quite tiresome when viewing for an extended period of time.
In this instructable, we are going to build a modern phenakistoscope. The phenakistoscope disc shall be mounted on a motor rotating at a speed that works with a strobing LED strip to make the images on the disc magically come to life when viewed with our naked eyes.
A traditional phenakistoscope is normally used by a person at a time. Our design allows a few people to view the animation at the same time which should be much more fun.
Our modern phenakistoscope can be controlled to rotate the disc in either clockwise or anti-clockwise direction, change the speed of rotation as well as vary the frequency of the strobe light. We will also be able to adjust the brightness of the strobe light for better viewing.
To build this project, basic electronics component soldering skill and some knowledge on using the Arduino are required.
You may like to view the following YouTube video to see what we are going to build for this project.
CAUTION:
For a small percentage of people with epilepsy, exposure to flashing lights at certain intensities or to certain visual patterns can trigger seizures.
This project requires strobing of the LED strip lights. If you experience discomfort looking at the images on the rotating disc or the light from the LED strip, you should stop looking at them immediately.
Step 1: Building the Electronic Circuit Board
For this project, we need a motor to spin at a consistent speed for the best visual effect.
We tested with cheap DC motors but they are not able to spin at a consistent speed over time. 134
Motor speed slowly drifts lower after running the motor for a while and this is quite noticeable for this project as we have to regularly compensate by adjusting the strobe light frequency in order to stabilize the animation. We may be able to mitigate this using PID motor control but this will require motor feedback and more elaborate program codes.
We have some faulty CDROM drives lying around and the salvaged CDROM Brushless DC (BLDC) motors from these drives work great for this project. We were able to drive these BLDC motors at a much consistent speed without using any feedback mechanism. The CDROM motor disc holder also allows us to easily mount a CD/DVD disc with a phenakistoscope image pasted onto it.
We will not be showing how to salvage the BLDC motors from CD or DVD drives as this information is readily found online such as the following Instructable
https://www.instructables.com/Disassembling-a-CDDVD-reader-and-reusing-its-parts/
and YouTube videos such as the following which also show where to connect to the 3 phases of the BLDC motor.
https://www.youtube.com/watch?v=GntH4ZcVKPU&t=244s
The electronic circuit and program codes to drive the CDROM Brushless motor are adapted from the following two Instructables:
https://www.instructables.com/Run-A-CDROM-Brushles...
https://www.instructables.com/Arduino-CDROM-BLDC-M...
We will be using two L293D ICs for driving the CDROM BLDC motor and we will be using a DC to DC Step-down module to supply power to the motor.
We will be driving the BLDC motor in open-loop operation mode without the need for rotor position sensors since reliability is not critical here and also to simplify the electronic circuit.
In our design, we will need 2 potentiometers. One for strobe light frequency control and another for motor direction change as well as for motor speed change.
A toggle switch will be used for the brightness control of the strobe light. Light will be brighter with each switch toggle and return to default brightness level after 10 brightness incremental steps. 16