more igniter questions

I've ordered some igniters from "Quickburst". I hope they arrive in time and are as good as they imply. Meanwhile, as a back up I'd like to try the Magnelite wires using my Igniterman pyrogyn. My question is does this work? I would appreciate any feedback from somebody who has tried it.

  Quoted Text Here  
Quickbursts are good, but I disagree. A high energy discharge unit should be used for any cluster with three or more motors. Lots of people don't use them and still have success, but you will have much better ignition when using a discharge coil. Do you really want to bet on all of the hand dipped igniters having the EXACT same resistance, or the club launch system having enough amps to fire all of them simultaneously? With a discharge unit, they will all fire at the same time.
Coupled with thermite igniters, your project will leap off the pad. :)
Mike Fisher Binder Design http://binderdesign.com

Mfreptiles wrote:
    <edited>
  Quoted Text Here  
Any more info on this type of launcher circuitry?
I am not familiar with the discharge coil design.
Is there a link to schematics or a project?
TIA

  Quoted Text Here  
Yup. http://www.rocketflite.com/magneblaster.asp
Mike Fisher

Mfreptiles wrote:
  Quoted Text Here  
Thanks, Mike. I misinterpreted what you were saying about a "discharge coil". I already had the schematics for the Magneblaster.
My launcher uses a motorcycle battery and does not have a relay. I built it to launch my B cluster altitude rocket and it fires 5 Solar igniters without a problem (so far!).
But I'm always on the lookout for new and better ideas.

<< http://www.rocketflite.com/magneblaster.asp
200 amps? How safe is that to handle?

  Quoted Text Here  
Fine, as long as you don't hold the clips and discharge it. Same as you wouldn't light a rocket motor while holding the motor in your hand.
If you cannot grasp the logic there, it's not safe for you. :)
Mike F.

<< Fine, as long as you don't hold the clips and discharge it. Same as you wouldn't light a rocket motor while holding the motor in your hand. >>
Sure, but I'd hate to be holding onto the clips when someone pushes the wrong launch button, or when there's a faulty relay or something. I've seen things like that happen with regular launch systems, but then you're only dealing with 12v.

RayDunakin wrote:
  Quoted Text Here  
The Magneblaster uses 12v as well. The 200 number was just a (possible) amperage rating, not a voltage.
Holding the clips wouldn't be any different from any other 12v powered system.

RayDunakin wrote:
  Quoted Text Here  
As safe as the 300-800 amps that flows in the starting motor of a typical automobile engine during startup. What the "magneblaster" is doing is using one of the solenoid relays designed for engine-starting service as the switching element in a relay launcher: the coil of this device can be powered by a low-current circuit such as a model rocket "launch controller" or the light-gauge wiring to the keyswitch on a car's dash panel, while the actual firing current flows through a short run of heavy gauge wire through the relay and the igniter... this system will supply very close to full battery voltage even to an igniter that draws several amperes of current.
If you clamped the clips together and then held down the launch button, you could probably cook the wiring... the same thing would happen to your car if you grounded out the starter lead at the motor and then held the keyswitch on "start".
-dave w

<< As safe as the 300-800 amps that flows in the starting motor of a typical automobile engine during startup. What the "magneblaster" is doing is using one of the solenoid relays designed for engine-starting service as the switching element in a relay launcher: the coil of this device can be powered by a low-current circuit such as a model rocket "launch controller" or the light-gauge wiring to the keyswitch on a car's dash panel, while the actual firing current flows through a short run of heavy gauge wire through the relay and the igniter... this system will supply very close to full battery voltage even to an igniter that draws several amperes of current. >>
Thanks Dave!

What do you disagree with?
  Quoted Text Here  

  Quoted Text Here  
That "you don't need a backup" ie high energy discharge unit. For clusters, the more amps the better, no matter what igniter you use.
Mike Fisher

On 16 May 2004 17:52:55 GMT, snipped-for-privacy@aol.com (Mfreptiles) wrote:
  Quoted Text Here  
I must admit what you say doesn't make sense. A backup is a high energy discharge unit? To me a backup would be another igniter.
Barney

  Quoted Text Here  
Read the entire thread please.
Mike F.

I read the entire thread, and I agree that what you said doesn't make any sense. What does "backup" have to do with "high energy discharge unit"? Are you using a non-standard meaning for some of the terms? Backup in my mind means an alternative in case the primary fails.
I looked at the site, and it looks as though he is using a coil as a current store. A good-sized lead acid battery can deliver hundreds of amps as well. What is special about the coil?
Just trying to learn...
-- David
  Quoted Text Here  

The "high energy discharge unit" in question is no more than a simple relay. A relay with a high current rating to be sure but nothing more. There is no energy stored anywhere other than in the battery.
The actual current delivered depends on the total circuit resistance. So it may deliver more or less than 200 amps.
As for the other comment in the thread that more current is always better, that is nor strictly correct. It is possible to vaporize the bridgewire of an ignitor so quickly that it simply blows the pyrogen off of it without igniting it. But a 12V system will not do this.
David wrote:
  Quoted Text Here  

<< The "high energy discharge unit" in question is no more than a simple relay. A relay with a high current rating to be sure but nothing more. There is no energy stored anywhere other than in the battery. >>
Ah, I see. Thanks for filling me in.

  Quoted Text Here  
What site is that? The only site I saw listed in this thread featured a 12 volt car battery and a starting relay. Did I miss something that actually used inductive storage?
Dave

DaveL wrote:
  Quoted Text Here  
Inductive storage???