Rocketman19
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Is this set- up correct? and can it run on 8 standard AA batteries?
Launch controller
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user 35280
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Why just double A batteries?
Rocketman19
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It seemed like the best option seeing that Estes uses them, although I didn't really research any other options. What else would I use besides maybe a 12 volt?
Rocketman19
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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?
Here’s my crude drawing. I have the polarity backwards on the button but works fine. The toggle resistor is actually 680ohms.
The button diagram.
Parts list:
Box: https://www.amazon.com/gp/product/B07C6XLZ2S/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Going to try a different key switch: https://www.amazon.com/dp/B0747LTGN3?psc=1&smid=A36ZH2MCHPKXUA&ref_=chk_typ_imgToDp
Toggle: https://www.amazon.com/gp/product/B07SZKVTPM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Button: https://www.amazon.com/gp/product/B083QLW8Z3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
LED: https://www.amazon.com/gp/product/B0798T9BXG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
9v holders: https://www.amazon.com/gp/product/B01C5J4L76/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
AA holders: https://www.amazon.com/gp/product/B014YSFMXI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Speaker wire: https://www.amazon.com/gp/product/B07YJNHCVH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The button diagram.
Parts list:
Box: https://www.amazon.com/gp/product/B07C6XLZ2S/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Going to try a different key switch: https://www.amazon.com/dp/B0747LTGN3?psc=1&smid=A36ZH2MCHPKXUA&ref_=chk_typ_imgToDp
Toggle: https://www.amazon.com/gp/product/B07SZKVTPM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Button: https://www.amazon.com/gp/product/B083QLW8Z3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
LED: https://www.amazon.com/gp/product/B0798T9BXG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
9v holders: https://www.amazon.com/gp/product/B01C5J4L76/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
AA holders: https://www.amazon.com/gp/product/B014YSFMXI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Speaker wire: https://www.amazon.com/gp/product/B07YJNHCVH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
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 don't think that setup is quite right. I can't quite tell how the continuity light is wired, but I don't think it will do what you want it to do.
When you arm the switch, you want a small amount of current to flow through the light, possibly a current limiting resistor, and the ignitor. Then, when you press ignition, it should short out the light (and resistor) to allow max current through the ignitor.
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.
LED is in the wrong place.
user 35280
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Like neil_w said a LiPO pack is a great idea. I personally use a small SLA 12V battery.
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.
user 35280
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I don’t use 6 volt battery packs, but anyway double A batteries just aren’t worth the hassle.
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.
Here is what your circuit should look like. I include an electronic schematic and a simple drawing of the circuit:
The idea here is that, when the "launch" push button is NOT pressed, the 1K ohm resistor and the LED are in series with the igniter. The 1K ohm resistor limits the current through the circuit to just a few milliamps. That is enough current to light up the LED, showing you that the igniter clips are connected correctly, but it is not enough current to actually heat up the igniter and set off the rocket motor.
When you press the push button, you create a "short" circuit through the push button, bypassing the resistor and the LED. Now the full current of the battery pack(s) is sent to the igniter (through the push button). This is enough current to cause the igniter to get hot. When the igniter gets hot, it sets off the rocket motor.
The LED will stop glowing when you press the push button because now the vast majority of the current in the circuit is bypassing the LED and flowing through the push button.
When you stop pressing the push button, the only way for current to flow is once again through the resistor and the LED. Again, only a small amount of current can flow. Since it is no longer bypassed, the LED comes back on.
The toggle switch in the circuit is just a simple "on/off" switch for the entire circuit. It serves the same role as the "safety key" in the Estes launch controller. Without the toggle switch in the "ON" position, the circuit is cut off and cannot operate at all.
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Scott_650
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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.
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.
Rocketman19
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That sounds like great idea having the LiPo pack and even better... I already have one on hand.
Rocketman19
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I will definitely use that as a model and I will add pictures once I get all that done. Thanks!!
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.
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?
It is certainly a reliable and capable device for what it is. I suppose it is designed for the parent who for fancy, science fair, or scout activity badge, would like to spend less than $50 on something they might use half a dozen times, and then leave in the garage. For this customer, an Estes controller is a great deal. It is sturdy enough. It is good enough for 1/4 A through D motors, with a 15ft extension. The The Estes "E" launch controller uses 4 AA batteries and has a 30ft extension. A built-in incandescent lamp limits current to the ignitor, but the lamp is on constant with ignitor connected. It is difficult to see (here in the desert southwest it is, in fact, impossible to see).
The reason Estes sells controllers is because many potential customers are not connected to a club and if they cannot launch the rockets Estes sells, no rockets will be sold. These Estes products are great, because some of those customers will catch the rocketry bug and go deeper into the hobby. That is a win for all of us.
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?
I'll be the first to admit that what I just said is not as simple as it used to be when we all had a Radio Shack around the corner. But with a little planning and some pointers on where to buy the parts, you could fashion a controller capable of a lot more, and one that would serve you for years of launching.
You might assume that as a vendor in this forum my only goal is to sell you something. My actual goal is to set new expectations; for launch gear that is more capable, more robust, safer, and easier to use than what you have been using. If I can sell you a Launch Controller that serves your needs then great. But maybe you are handy with wire and tools and do not wish to spend that much money when you could build something that is good enough for you. You might even impress yourself and your fellow rocketeers.
I'll be back in a few hours with a schematic, parts list, Theory of operation, and tips about what tools you will need to do the job. If you can read an electrical schematic, you are already half way there. You can build a really capable launch controller with basic off-the-shelf components.
I have a question for you. If I could sell you a parts kit for this project, would that be of interest to you?
It is certainly a reliable and capable device for what it is. I suppose it is designed for the parent who for fancy, science fair, or scout activity badge, would like to spend less than $50 on something they might use half a dozen times, and then leave in the garage. For this customer, an Estes controller is a great deal. It is sturdy enough. It is good enough for 1/4 A through D motors, with a 15ft extension. The The Estes "E" launch controller uses 4 AA batteries and has a 30ft extension. A built-in incandescent lamp limits current to the ignitor, but the lamp is on constant with ignitor connected. It is difficult to see (here in the desert southwest it is, in fact, impossible to see).
The reason Estes sells controllers is because many potential customers are not connected to a club and if they cannot launch the rockets Estes sells, no rockets will be sold. These Estes products are great, because some of those customers will catch the rocketry bug and go deeper into the hobby. That is a win for all of us.
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?
I'll be the first to admit that what I just said is not as simple as it used to be when we all had a Radio Shack around the corner. But with a little planning and some pointers on where to buy the parts, you could fashion a controller capable of a lot more, and one that would serve you for years of launching.
You might assume that as a vendor in this forum my only goal is to sell you something. My actual goal is to set new expectations; for launch gear that is more capable, more robust, safer, and easier to use than what you have been using. If I can sell you a Launch Controller that serves your needs then great. But maybe you are handy with wire and tools and do not wish to spend that much money when you could build something that is good enough for you. You might even impress yourself and your fellow rocketeers.
I'll be back in a few hours with a schematic, parts list, Theory of operation, and tips about what tools you will need to do the job. If you can read an electrical schematic, you are already half way there. You can build a really capable launch controller with basic off-the-shelf components.
I have a question for you. If I could sell you a parts kit for this project, would that be of interest to you?
Here is a schematic and a drawing of a "heavy duty", 12V launch controller. This should have enough current to ignite a 2 or 3 motor cluster of black powder motors. It should also have enough current to ignite the lower powered composite motors. I must admit that I have no experience with composite motors but, theoretically, this circuit should work.
Notice that, if you up the voltage to 12V (from 6V), you need a resistor value that goes up proportionally. Since the 6V controller used a 1K ohm resistor, this 12V controller uses a 2.2K ohm resistor.
Since LiPo and SLA batteries can put out a LOT of current, I have added a fuse to the circuit, as @HyperSonic wisely suggested.
Also, since the current of this circuit is higher, I have noted that you should use 18 gauge (heavier gauge) wires for your igniter clip wires.
Attachments
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.
Because, if I just want to launch LPR rockets in the park, such a system would be insane overkill.
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.
I will stop now.
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.
A "slo-blo" fuse might be the solution.
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.
This is where a “relay” style controller starts to make sense. That may be more complex, however, than the OP needs.
MidOH
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If I was going to bother making a controller, it would be lipo powered. And my lipos would laugh at 100amps load. They'll roast your leads long before getting anywhere close to internal thermal overload.
So I'd run a much larger fuse, and/or a relay.
So I'd run a much larger fuse, and/or a relay.
Do you connect that to the PSII through the JST connector? And what amp hours is your battery?
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