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 42 users online :: 5 registered, 0 hidden and 37 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

ignition coil

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: ramses » Mon Jun 07, 2010 3:52 pm

NICE!

are you using the large, can-type ignition coil, or one of the smaller ones? What Frequency do you estimate your spark works at?
  • 0

POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
ramses
Major General
Major General
 
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm
Reputation: 3

Unread postAuthor: Hotwired » Mon Jun 07, 2010 4:49 pm

It's a small coil, the kind you might get on small bikes, maybe some lawnmowers. With a large coil I might get longer sparks but at the expense of size and weight.

A full size car coil is much bigger than the entire build including battery pack so... nothing to gain.

Guess is about 20 sparks/second with 3V input from fresh batteries but as I say it depends on voltage, you can hear the difference when you've had it running for a while.

Mind you, for cannon ignition, the difference between 0.05 and 0.1 of a second is irrelevant. It charges a capacitor to the same degree for each spark and just one spark has been able to light gas mixes reliably.
  • 0

User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: ramses » Mon Jun 07, 2010 8:38 pm

Thanks, that's the answer I was hoping for. Are you using a SIDAC to dump the capacitor?
  • 0

POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
ramses
Major General
Major General
 
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm
Reputation: 3

Unread postAuthor: Hotwired » Tue Jun 08, 2010 10:31 am

Nope, it's a spark gap type switch.

I'm musing over solid state alternatives but I expect I'd either have to lower the frequency, restrict runtime to short bursts or increase the size of the package.

Those 30kv ignitors sold by USG and others who do cheap spark ignitors for gas use a solid state component.

[youtube]http://www.youtube.com/watch?v=LhM_c6YoZkc[/youtube]

I can't say for sure which component it is because the versions I have use a switching component which looks like a diode, has worthless markings and could be any one of a number of things which conduct at X voltage and a sidac is one of those.
  • 0

User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Previous

Return to Combustion Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'