Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 52 users online :: 5 registered, 0 hidden and 47 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Ignition idea

Post questions and info about combustion (flammable vapor) powered cannons here. This includes discussion about fuels, ratios, ignition systems, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: jimmy101 » Fri Jan 09, 2009 3:22 pm

The crystal last forever, piezo's never "run out". When they fail it is either because of the crystal breaking, or more commonly, a failure in the hammer mechanism.

Piezo's are used as the "tweeter" speaker in some stereo speakers. They last forever (or until a 3 year old pokes their finger through'm :x ). Put an AC voltage into a piezo and it vibrates. Vibrate a piezo and it makes an AC voltage.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3128
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: john bunsenburner » Fri Jan 09, 2009 4:06 pm

pretty cool, but wouldnt i need two wires to run a current through the piezo?
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Unread postAuthor: starman » Fri Jan 09, 2009 5:17 pm

jimmy101 wrote:Put an AC voltage into a piezo and it vibrates. Vibrate a piezo and it makes an AC voltage.


FWIW, a standard voice coil speaker will do the same thing. I've actually built an enclosure for and used a 6" car speaker to perform as a Kick Drum microphone! Yes, the sound is huge out of this "mic" but only at low frequencies. Sounds like crap above 400 hz or so. You would usually use this in conjunction with a standard mic inside the drum picking up the beater and this on the outside picking up the boom.

Image
Image
  • 0

User avatar
starman
Donating Moderator
Donating Moderator
 
Posts: 3041
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC
Reputation: 0

Unread postAuthor: jimmy101 » Fri Jan 09, 2009 5:53 pm

john bunsenburner wrote:pretty cool, but wouldnt i need two wires to run a current through the piezo?

All piezos have two wires (or other types of electrical contacts). Sometimes though the second contact is just a piece of metal somewhere on the piezo. On common configuration for BBQ igniter piezos is a single wire and a metal cap. Take a look at the photo of the Piezoelectric Igniter at the SciToys page: http://www.scitoyscatalog.com/Merchant2 ... y_Code=FCC
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3128
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: john bunsenburner » Sat Jan 10, 2009 1:19 pm

Yup thats like mine just mine has a singe wire not a bundel, its geat to ignite things seeign i dont have a lighter any more(guess where the piezo cam from). I always need to earth the mtal object the fuel is on to light it, i do so with my fingers, is that correct or is it just a wierd thign i came up with and not a fact?
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Previous

Return to Combustion Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], Yahoo [Bot]

Reputation System ©'