Rocketman19
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- Joined
- Jul 14, 2020
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- 23
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Why just double A batteries?Is this set- up correct? and can it run on 8 standard AA batteries?View attachment 473748
It seemed like the best option seeing how Estes uses them in their controller, although I haven't done much research into other power sources. What would you suggest then?Why just double A batteries?
Is this set- up correct? and can it run on 8 standard AA batteries?View attachment 473748
It seemed like the best option seeing how Estes uses them in their controller, although I haven't done much research into other power sources. What would you suggest then?
For a standard, one engine launch controller, 4 AA’s is enough. You need a resistor (about 1K or so should do it) in series with the LED.
Like neil_w said a LiPO pack is a great idea. I personally use a small SLA 12V battery.It seemed like the best option seeing how Estes uses them in their controller, although I haven't done much research into other power sources. What would you suggest then?
Four fresh, AA, alkaline batteries will give you 6 volts and enough current (amperes) to ignite a black powder A through E rocket motor. You are running your two 6 volt battey packs in parallel, so you are getting the same 6 volts but more current. It’s not necessary as long as you are not launching clusters. One battery pack of 4 AA’s is adequate.Why just double A batteries?
I don’t use 6 volt battery packs, but anyway double A batteries just aren’t worth the hassle.Four fresh, AA, alkaline batteries will give you 6 volts and enough current (amperes) to ignite a black powder A through E rocket motor. You are running your two 6 volt battey packs in parallel, so you are getting the same 6 volts but more current. It’s not necessary as long as you are not launching clusters. One battery pack of 4 AA’s is adequate.
That's pretty much how the Estes controller works. I tried to figure out how much of a resistor it uses but not sure it has one. Technically, the light is in itself a resistor.Here's a generic simple launch controller circuit I found here:
View attachment 473800
For simple single-pad duty, this is all you need. The continuity light should be a bright LED in series with a 1K resistor, roughly.
Is this set- up correct? and can it run on 8 standard AA batteries?View attachment 473748
You are correct about the incandescent bulb acting as a resistor - for as simple as it is the Estes #2220 Electron Beam Launch Controller works well with fresh alkaline batteries.That's pretty much how the Estes controller works. I tried to figure out how much of a resistor it uses but not sure it has one. Technically, the light is in itself a resistor.
As I found out, the NAR safety code requires the ignition switch to be spring activated so when you release the button, the power turns off. I accidently bought the catch type and returned it for the spring type.
I figured out the Estes controller won’t ignite the E30 motor. @kuririn reminded me after a clip broke off of my DIY 18v controller in the field.You are correct about the incandescent bulb acting as a resistor - for as simple as it is the Estes #2220 Electron Beam Launch Controller works well with fresh alkaline batteries.
That sounds like great idea having the LiPo pack and even better... I already have one on hand.AAs don't have a lot of oomph. They can handle a single LPR motor OK. The Estes PSII controller (recommended at ~$30) uses 6 C batteries, which can handle small clusters, or you can optionally hook it to a LiPo pack, which can deliver *tons* of current and launch pretty much anything.
I will definitely use that as a model and I will add pictures once I get all that done. Thanks!!Here is what your circuit should look like. I include an electronic schematic and a simple drawing of the circuit:
View attachment 473828
When using a Lipo pack (which is capable of a LOT of current) be sure to add a safety fuse (5 to 10 amp) right after the battery V+ before the SW1. Should something happen that causes V+ to short to V- (strange things do happen) this fuse will protect the battery from catching fire.That sounds like great idea having the LiPo pack and even better... I already have one on hand.
That sounds like great idea having the LiPo pack and even better... I already have one on hand.
To me, the PSII controller is a more worthy model emulate for the typical home-launcher. Especially with a LiPo pack, it is quite capable.I see some good ideas here. But the shared assumption seems to be that an Estes controller is a standard to apply to your needs. Can we think about that for minute? Who is the little Estes controller designed for?
Because, if I just want to launch LPR rockets in the park, such a system would be insane overkill.I am assuming that you are past this stage. So here is my question; if you are going to the trouble of building a launch controller, why would you settle for a 3 or 6vdc system limited to 30 ft? For a modest investment in parts you could put together a 12v system with a launch relay and get a 50, 100, or even 300ft extension. If you are going to build a controller then why not build something capable of whatever your aspiration grows to?
OK, now I am on a roll. Here is an even more improved launch controller schematic and drawing. This version has TWO push buttons for the "launch" buttons. You must press both buttons, simultaneously, to launch. This is just a safety feature, to prevent accidental launches.
I will stop now.
View attachment 473893
Fuses come with different timing elements. You can get fast blow, slow blow, or anywhere in between. But like brockwood was saying, this fuse needs to hold the full firing current for a few seconds, but will open up BEFORE you reach melt down current. This value will depend on the size (mAh) of your Lipo pack.Actually, a 5 amp fuse might be too low of a value. A LiPo or SLA battery can supply more than 5 amps (for a short period of time). Play with the value of the fuse until it does not blow too quickly. Maybe start with a 10 amp fuse and play with the value. The idea of the fuse is just to protect from a true short circuit. You do not want the fuse to blow when the circuit simply provides the high current, for a short period of time, needed to ignite the rocket motor.
Fuses come with different timing elements. You can get fast blow, slow blow, or anywhere in between. But like brockwood was saying, this fuse needs to hold the full firing current for a few seconds, but will open up BEFORE you reach melt down current. This value will depend on the size (mAh) of your Lipo pack.
Do you connect that to the PSII through the JST connector? And what amp hours is your battery?I personally use a small SLA 12V battery.
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