Propeller Clock-An Amazing Illusion

It was great to see a propeller clock circuit and its working.The great use of chips display the illusion of a clock in air with LEDs.

A motor spins the "propeller", and a small microprocessor keeps track of time and changes the pattern on seven LEDs with exact timing to simulate a 7 by 30 array of LEDs. It is an illusion, but it works nicely.



If you want to build this clock, you will need a few things, including:

  Skill with motors and mechanical things.
  Prior electronic experience.
  A dead VCR or floppy drive or other source of a suitable motor and miscellaneous parts.
  A programmer that will program a PIC16C84 or 16F84 microprocessor.

Propeller clocks were to my knowledge first started by Bob Blick then many people started copying his idea and adding certain improvements along the way. Propclocks are really pretty complex devices, utilizing a PIC microcomputer that performs instructions at 10mhz. The PIC is the brain of the device and does most of the work involved in making the LEDs light up at just the right time so that it appears there are numbers, and in the analog mode hands suspened in mid air. On my version of the clock you change the mode and time setting while it is still spinning at about 1150 PRM. This is done through carefully alligned photo detectors and LEDs. These sensors are located on the rear of the spinning motor so they dont affect the look of the clock at all.

Here is its circuit diagram.

Here is the video: