propeller clock amazing illusion

Posted on Feb 7, 2014

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. Propeller clocks were to my knowledge first started by Bob Blick then many people started copying his idea and adding certain improvements

propeller clock amazing illusion
Click here to download the full size of the above Circuit.

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.

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