I had this idea for a growling and screaming altoids tin based on the 555 timer running in astable mode several days ago, and just today while reading Hackaday I see that Dino from Dinofab.com and Hackaweek.com just built it! I was like, “sonofa…” but then saw he did not implement it quite the way I had planned, so off to the lab! After some circuit simulating, and general goofing around on the breadboard, this circuit emerged. It uses a photoresistor and an interesting feedback path which helps to distort the output and actually widens the range of frequencies generated. The best part is it only draws 30mA and is loud as hell!
To be completely honest, I did NOT look at Dino’s circuit or video before I started my schematic. We both ended up with 100uF caps in series with the speaker, but that’s about the only similarity. It just goes to show the 555 is a very versatile chip to have in stock at your lab.
Download the Growl and Scream Altoids Prank Schematic here: Growl and Scream Altoids Prank - Brett (FightCube.com) (557)
Well I just want to say, thank you Dino for motivating me to complete this project! If I didn’t see your Altoids Screamer project today I might not have every taken this idea out of my head. It’s loud and annoying and so very very perfect
Don’t forget to watch the videos below: