Hypnotic Hardhat Headphones




About: Retired Math teacher who needs a hobby! So I tinker with stuff: Arduino, welding, my 1958 TR-3 , my tennis serve

Firstly(is that a word?) the hat is not so hard just a kids plastic hat that looks like a hard hat. 

This project was a way to learn more about 555 timer circuits, create a Knight Rider LED display using a 4017 IC , use an old set of headphones I had around and end up with a way to listen to my iPod and look completely ridiculous at the same time.  Also may just hypnotize anyone staring at me.

Basically what was done here:

1. Created the 555 circuit  & the Knight Rider Led circuit using a combination of the following 2 web sites:


I more closely followed the second one but did use slightly different resistors and capacitors.

4017 changes:
I used 200 ohms for the LED resistors instead of the 1k it shows(I had lots of 100 ohm resistors but few 1K's).  I connected pins 13, 15  and 8 from the 4017 directly to ground without the 100 K resistor .  I did not use the 1n4148 diodes. I had bread boarded it this way and it seemed to work ok.

555 timer changes:
I did not use the 10k from pin3 to pin 14

I used a 4.7uf capacitor instead of the 10uf shown.

The hypnotic spiral is a CD mounted to the CD motor .   It is wired to 3V using a separate circuit from the 555 timer circuit. Both circuits have a slide switch to turn them on.   I included a 500 ohm potentiometer so I could control the speed of the CD a bit better.

The headphones are secured to the inside thru a screw in the middle and wire ties to the sides. 

I used gaffer tape to cover the wires to the LEDs so as to hold them in place and provide a slightly more comfortable fit when wearing the helmet.

The circuits are soldered to a PCB and then attached to a small block of wood . The wood is secured to the helmet by double backed sticky tape. The tape is used to hold the batteries and the switches in place, also.

Here is a short video showing the helmet working.



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