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Jarrett

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Hi this is Jarrett and I am going to start building my own simple launch controller and have a few questions. First of all how many volts do I need? I am going to be launching B-D engines and am thinking something like 9 volts. I was thinking I would have a lay out like this:http://www.electroschematics.com/wp-content/uploads/2014/03/generic-wiring-diagram.png, and I would also like to add a safety key after the igniter. How does this sound?

Thanks!
-Jarrett
 

Tonimus

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9V batteries don't make very good controller batteries. They can't dump a whole lot of power all at once. 6v is enough if you use AA batteries. That is probably the most common solution in that size range. You could also use a lipo, but then you have to be extra cautious about what kind of light you use, so that you do not pop your igniter early.

Also, why would you want to add a second key? It would serve no purpose. (Not that I haven't ever done anything without a purpose.)
 

Handeman

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I guess the question is, how long do you want to use the controller and for what?

I started out launching A-C motors with my son and the Electron Beam wasn't cutting it. I like building things so I put together a 6"d x 12"w x 10"h box that had the switches and LEDs on top and a motorcycle battery inside. This worked great for A-E BP motors, including 3 and 4 motor clusters that I worked up to. Then it was on to composite motors with Copperhead igniters. That box now sits in my basement collecting dust.

The point is, build something for where you will be going in the not to distant future instead of where you are right now. If you are launching A-D BP motors now, I would recommend something that will handle 3 or 4 motor clusters and AP motor igniters. That would mean 12V and being able to source 10 - 20 amps for short times. I use a car starter now
 

Jarrett

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Okay. I am going to do 6v and eventually 12v.

Thanks for the help!
-Jarrett
 

mccordmw

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I'm curious about why people say you need higher voltage for APCP vs BP motors. I launch F20 motors using a pyrogen-dipped ematch with a standard Estes controller on 30' of wire. I've also used this same setup to test fire 54mm ANSU motors. Isn't the limitation simply wire length + current needed to trigger the igniter? Those trigger with very little current.

I can see needing higher voltage when you step up to HPR and need to be farther back. But then, I see more people using relays at that point.

So regardless or motor size you're firing, figure out how long you want the wire (so you aren't too close to the launch), and what current your planned ematches need to ignite.
 

Reinhard

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I'm curious about why people say you need higher voltage for APCP vs BP motors. I launch F20 motors using a pyrogen-dipped ematch with a standard Estes controller on 30' of wire. I've also used this same setup to test fire 54mm ANSU motors. Isn't the limitation simply wire length + current needed to trigger the igniter? Those trigger with very little current.

I can see needing higher voltage when you step up to HPR and need to be farther back. But then, I see more people using relays at that point.

So regardless or motor size you're firing, figure out how long you want the wire (so you aren't too close to the launch), and what current your planned ematches need to ignite.
The higher voltage requirement is not determined by the motor propellant but by the igniter type. Aerotech igniters (FirstFire, Copperhead) typically require around 12V. CTI uses ematches. Those can be ignited with very low voltages. Other manufacturers and aftermarket igniters have their own characteristics.

Reinhard
 

mccordmw

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The higher voltage requirement is not determined by the motor propellant but by the igniter type. Aerotech igniters (FirstFire, Copperhead) typically require around 12V. CTI uses ematches. Those can be ignited with very low voltages. Other manufacturers and aftermarket igniters have their own characteristics.

Reinhard
I use CTI ematches and my own pyrogen-dipped ematches. They do ignite easily.
 

sl98

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As far as power supply, I would also recommend a car starter / jump pack. You can get a decent one at Walmart for $30-40 that is lightweight and small in size. They also come in handy if you have a dead battery. I have an older version of this one. Schumacher

Another thought is use a long piece of lamp cord or other similar wiring to go to your power supply and a couple of medium size alligator clips. That way you can use a variety of power sources (including 9V batteries).

2016-09-25 08.23.52.jpg2016-09-25 08.25.16.jpg

You can easily convert a Estes Electron Beam controller or even a PSII controller to use an external power source (starter, 9V battery, cell). I use the electron beam controller above (right) with my starter pack to ignite both home made and commercial igniters that come with AT mid and high power motors as well as Estes igniters. You can also clip on a 9V battery using the alligator clips if you just want to launch Estes igniters.
 
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