Large Club Launch Controller

Diagram for idea in my last post

View attachment controler w individual continuity.pdf

rbeckey said:

Diagram for idea in my last post

Click to expand...

I think this is starting to make sense to me. That is a dangerous sign.

The way I test myself is to draw up "my version" and post it for criticism.

For me, electronics are much like the tax code, quantum mechanics, special relativity, the Holy Trinity and women. For each, I must be very, very careful if they start making sense. That is a sure sign that I don't understand something important!:surprised:

I just caught a possible problem. I can't use that individual LED diagram. I don't know what kind of LED would take the full charge to the igniter, but I suspect they come rather dear.

rbeckey said:

I just caught a possible problem. I can't use that individual LED diagram. I don't know what kind of LED would take the full charge to the igniter, but I suspect they come rather dear.

Click to expand...

NUTS!!!!

Just when I thought I had it.

You've given of your time and yourself to help me and I appreciate it. If you figure a solution, I would appreciate that too but I am well satisfied with the help and clarity you (and others) have extended me.

Just having seen the side of the circuit to the left of the pad select switches has aided in my very imperfect understanding.

Thank you.

Hey It is no problem to help. I redesined the pad I built many times before it got made.

I have tried again and found a problem myself and I have tried to figure it out.
hopefuly I got it this time.

Some information for you; A DPDT switch has 2 seperate inputs and each input can be switched to 2 seperate outputs. It is 2 SPDT linked together, so when you switch one you switch the other at the same time.

A resister will allow voltage through it, it also drops the voltage to the rest of the circuit because it adds resistance to the total circuit. resistor + load = total restance. The igniter has a restance value to it also and aslo takes a certain amount of amprage to burn the wire in two. The addition of the resister will add to the resistance of the igniter and therefore the amount of amprage to burn the igniter is greater and so the same battery supply will not burn the igniter with the resister installed.

A led has a set working voltage rating and if you apply more voltage to it than what it is rated for you can burn it up. Therefore a resister is installed in series with the led to drop the voltage going through the led and this resistor is called a current limter. Normaly a 1k to a 1.5 k ohm resister is used for 9v to 12v applications. If you use a led that is rated for 12vdc it has this resistor installed inside of it already. If you use a led by its self you have to add a resistor in series to it to keep it from burning up.

I had to make a change to the circuit as far as the wireing was.
I made up 3 diagrams which shows the voltage/current flow through the circuit in red.

The first one shows the votage path with s1 in the pad active position(not selected), s2( the launch switch) not depressed. Yellow led lit, green led not lit.

The second one shows the voltage path with s1 in the pad selected position, s2 not depressed. Yellow led not lit, Green led lit.

The trird one shows the votage path with s1 in the pad selected postion, s2 in the launch postion. When pressing s2 it pypasses the 1.5k ohm resistor allowing full voltage and current to go straight to the igniter and not through any resistors or leds, and therefore igniting the rocket motor.

Keep in mind that the power to the cluster led is in the on state even though I did not give it any voltage path indication.

I hope this helps clear up any more thoughts that you may have. If not just ask again and there might be another revision thought up.

View attachment simple launch circuit ca.JPG

View attachment simple launch circuit da.JPG

View attachment simple launch circuit ea.JPG

KDRaven said:

Hey It is no problem to help. I redesined the pad I built many times before it got made.

I have tried again and found a problem myself and I have tried to figure it out.
hopefuly I got it this time.

Some information for you; A DPDT switch has 2 seperate inputs and each input can be switched to 2 seperate outputs. It is 2 SPDT linked together, so when you switch one you switch the other at the same time.

A resister will allow voltage through it, it also drops the voltage to the rest of the circuit because it adds resistance to the total circuit. resistor + load = total restance. The igniter has a restance value to it also and aslo takes a certain amount of amprage to burn the wire in two. The addition of the resister will add to the resistance of the igniter and therefore the amount of amprage to burn the igniter is greater and so the same battery supply will not burn the igniter with the resister installed.

A led has a set working voltage rating and if you apply more voltage to it than what it is rated for you can burn it up. Therefore a resister is installed in series with the led to drop the voltage going through the led and this resistor is called a current limter. Normaly a 1k to a 1.5 k ohm resister is used for 9v to 12v applications. If you use a led that is rated for 12vdc it has this resistor installed inside of it already. If you use a led by its self you have to add a resistor in series to it to keep it from burning up.

I had to make a change to the circuit as far as the wireing was.
I made up 3 diagrams which shows the voltage/current flow through the circuit in red.

The first one shows the votage path with s1 in the pad active position(not selected), s2( the launch switch) not depressed. Yellow led lit, green led not lit.

The second one shows the voltage path with s1 in the pad selected position, s2 not depressed. Yellow led not lit, Green led lit.

The trird one shows the votage path with s1 in the pad selected postion, s2 in the launch postion. When pressing s2 it pypasses the 1.5k ohm resistor allowing full voltage and current to go straight to the igniter and not through any resistors or leds, and therefore igniting the rocket motor.

Keep in mind that the power to the cluster led is in the on state even though I did not give it any voltage path indication.

I hope this helps clear up any more thoughts that you may have. If not just ask again and there might be another revision thought up.

Click to expand...

Thanks again for the effort and especially the color coded flow paths for the electrically challenged. The part that's no shown is when the current flows through me to the ground giving the flourosope effect!

Thanks too for the explanations. I am working through another diagram at present but little things like kids and work are chewing up too much time. Oh, and wifey gets a slice of that too. I also have a club launch coming up this Saturday and have priortized finishing some stuff on the bench and a few repair jobs. I'll post the revisions as soon as I can get them finished.

Thanks again.

Well JAL3 it looks like I have not been doing too great in helping you design your launch controler. I was looking over the diagram in my head and on paper last night/ this morning and it will work by itself as one pad but not with multiple pads. there is a return loop voltage line present when using toggle switches for the pad select switch. there is a couple of ways around this I figured out but it looks like some one else has a better idea than what I have been trying to do for you.
When I made the Pad that my club is using I just built it simple and used push buttons instead of toggels and have a launch switch for every pad and one for the main power that has to be held down with the pad button to launch. We dont do any multiple launches other than drag racing and that is done with remote buttons that the individuls that are racing press.

Dont get discouraged there is still a light at the end of the tunnel just hope it is not a train.

KDRaven said:

Well JAL3 it looks like I have not been doing too great in helping you design your launch controler. I was looking over the diagram in my head and on paper last night/ this morning and it will work by itself as one pad but not with multiple pads. there is a return loop voltage line present when using toggle switches for the pad select switch. there is a couple of ways around this I figured out but it looks like some one else has a better idea than what I have been trying to do for you.
When I made the Pad that my club is using I just built it simple and used push buttons instead of toggels and have a launch switch for every pad and one for the main power that has to be held down with the pad button to launch. We dont do any multiple launches other than drag racing and that is done with remote buttons that the individuls that are racing press.

Dont get discouraged there is still a light at the end of the tunnel just hope it is not a train.

Click to expand...

Don't sweat it. You found the problem which is more than I ever would (until I had assembled lots of $$$ that didn't work). I do appreciate your input.

What I would like to do is probably overly complicated. THe problem is that I have in my head the way I want it to work. my head + anything = trouble.

Thanks

When I was thinking about the circuit this morning I drew up one and after reading your hypot senerio I was able to understand the ckt and came up with this one.
After hooking up the rockets on the pads, flip the power switch which will energize the red leds showing what pads can be selected.
After deciding which pads to select flip the enable switch which will turn out the red led and turn on the yellow led while supplying voltage to the green led for cont. check with the igniter hooked up the green led will also light. also inserting the relay coil into the ckt.
Pressing the launch switch will inergize the selected relays causing the selected rockets to be launched.
One pad, all pads or a combination of pads can be selected and launched.

Yes one can also put a buzzer in the circuit to go off when there is a completed ckt. I did not show it in the ckt.

This circuit is using relays which is old school but I dont know how to use the newer tecnogily of micro processors, or digital circuits because I lost too much knowledge over the years by not keeping up with electronics. I use the basics, switches, diodes, leds, relays, and such for my ideas.

View attachment launch ckt b.JPG

JAL3 said:

For me, electronics are much like the tax code, quantum mechanics, special relativity, the Holy Trinity and women.

Click to expand...

JAL3, I am every bit as frustrated with circuit design as you seem to be. It has always been my experience that after you get up-to-speed with the theory and practice, this sort of knowledge is something that evaporates quickly if you don't use it often (well, at least it is for me). So I appreciate you being the "point man" and taking all the hits on this issue, but you should know that there are many more of us circuitry-impaired who are out here taking notes.

This particular thread will come in handy as another source of info to hand over to a local church scout group that wants to build their own club launcher. It has been waaaay too long since the last time I built one, and I don't have a clue where my old notes are.

On a slightly different note: does anyone have any brilliant suggestions how to (cheaply) design/build a launcher head (that holds the launch rod) that is adjustable in both azimuth and elevation? (and simple enough to operate that kids can do it) Any leads on a vendor that sells some kind of kit for this?

KDRaven said:

When I was thinking about the circuit this morning I drew up one and after reading your hypot senerio I was able to understand the ckt and came up with this one.
After hooking up the rockets on the pads, flip the power switch which will energize the red leds showing what pads can be selected.
After deciding which pads to select flip the enable switch which will turn out the red led and turn on the yellow led while supplying voltage to the green led for cont. check with the igniter hooked up the green led will also light. also inserting the relay coil into the ckt.
Pressing the launch switch will inergize the selected relays causing the selected rockets to be launched.
One pad, all pads or a combination of pads can be selected and launched.

Yes one can also put a buzzer in the circuit to go off when there is a completed ckt. I did not show it in the ckt.

This circuit is using relays which is old school but I dont know how to use the newer tecnogily of micro processors, or digital circuits because I lost too much knowledge over the years by not keeping up with electronics. I use the basics, switches, diodes, leds, relays, and such for my ideas.

Click to expand...

It seems like despite best intentions, I keep getting snowed under and am not getting around to working on this. I haven't even gotten in any build time recently. Event tonight, I found i had to recycle my ash Wednesday sermon from last year. The only one who noticed is the guy who runs the sound system.

I hope to put some time in on this stuff soon. Thanks again for you efforts.

JAL

powderburner said:

JAL3, I am every bit as frustrated with circuit design as you seem to be. It has always been my experience that after you get up-to-speed with the theory and practice, this sort of knowledge is something that evaporates quickly if you don't use it often (well, at least it is for me). So I appreciate you being the "point man" and taking all the hits on this issue, but you should know that there are many more of us circuitry-impaired who are out here taking notes.

This particular thread will come in handy as another source of info to hand over to a local church scout group that wants to build their own club launcher. It has been waaaay too long since the last time I built one, and I don't have a clue where my old notes are.

On a slightly different note: does anyone have any brilliant suggestions how to (cheaply) design/build a launcher head (that holds the launch rod) that is adjustable in both azimuth and elevation? (and simple enough to operate that kids can do it) Any leads on a vendor that sells some kind of kit for this?

Click to expand...

I think I am more frustrated with myself than I am with electronics. Electricity has never been intuitive for me but this is one area where I am having a much more difficult time since the brain tumor. It gets frustrating.

I'll gladly take the hits because thats the only way I'll ever really learn this stuff and I WANT TO LEARN IT. Besides, I seem to be very good at displaying my ignorance; it is a lifetime habit. I hope that this info does come in useful to others and i do appreciate the efforts others are making to educate me. I just wish they didn't have to work so hard at it.

I too am looking around for some ideas for the more mechanical aspects of GSE but have not put much effort into it yet. What we have works tolerably well...for now.

I wish you luck with your BSA project. I miss working with scouting.

powderburner said:

On a slightly different note: does anyone have any brilliant suggestions how to (cheaply) design/build a launcher head (that holds the launch rod) that is adjustable in both azimuth and elevation? (and simple enough to operate that kids can do it) Any leads on a vendor that sells some kind of kit for this?

Click to expand...

NARTS sells the plans for an excellent launcher pivot. It's the design that has been used at NARAM for at least the past 10 years, and a similar design is being used for the pivots at this year's NSL. We used some of them for the first time at our sport launch last weekend, and they were well received.
The plans call for Corian, but you can substitute wood or metal.

RoyGreen said:

NARTS sells the plans for an excellent launcher pivot. It's the design that has been used at NARAM for at least the past 10 years, and a similar design is being used for the pivots at this year's NSL. We used some of them for the first time at our sport launch last weekend, and they were well received.
The plans call for Corian, but you can substitute wood or metal.

Click to expand...

Any chance you could give the link or the item designation? I skulked around over there for a bit and did not find anything quite as described.

Thanks,

JAL

JAL3 said:

Any chance you could give the link or the item designation? I skulked around over there for a bit and did not find anything quite as described.

Thanks,

JAL

Click to expand...

look for Launcher Pivot. should be in both the online ordering and the pdf catalog.

RoyGreen said:

look for Launcher Pivot. should be in both the online ordering and the pdf catalog.

Click to expand...

Found it. Thanks,

JAL

Well back into the fray with another submission. Large field controllers really need to have relays so I am attaching my relay design (actually I doubt I am the first to think of this configuration). This design is actually the base for my new computer based controller. It's scalable. The mockup worked fine and I'm hopeful the diagram is accurate to that at least.

It's a lot of parts and lots of wires and partly why we went digital over the distance between the controller and many pads. So complicated. But for a basic relay controller with continuity feedback and individual pad arm it's a possibility.

Resistor values assume high MCD LEDs and were chosen to limit forward current to 10ma or less with about 60% efficiency, and 8ma or less through the ignitor. your mileage will vary.

I know this level of circuitry is hard because I screw it up myself almost every time. It IS rocket science after all.

Dave

Looks good , but check the wiring feeding the positive ends of the pad 2 and 3 continuity check LEDs. Looks like they should be extended to the left a bit...

flight4 said:

Well back into the fray with another submission. Large field controllers really need to have relays so I am attaching my relay design (actually I doubt I am the first to think of this configuration). This design is actually the base for my new computer based controller. It's scalable. The mockup worked fine and I'm hopeful the diagram is accurate to that at least.

It's a lot of parts and lots of wires and partly why we went digital over the distance between the controller and many pads. So complicated. But for a basic relay controller with continuity feedback and individual pad arm it's a possibility.

Resistor values assume high MCD LEDs and were chosen to limit forward current to 10ma or less with about 60% efficiency, and 8ma or less through the ignitor. your mileage will vary.

I know this level of circuitry is hard because I screw it up myself almost every time. It IS rocket science after all.

Dave

Click to expand...

Have I got a headache...

As far as relays are needed if using at least 16ga. wire how rar can one go with out enough voltage drop to ignite most egniters when useing a good 12v car battery? We (my club) is able to go to at least 50' or more with out having to use a remote battery/relay controler. We use one on our HPR pad which is out at 200 to 220'.

We currently use long launch wires for most of the pads also. Works fine. One benefit of putting the current source closer to the pad is more current, which lights the ignitor/motor faster. Especially with multiple ignitor/clusters. It's a noticeable difference when using a relay box vs traditional long leads. Probably doesn't matter most of the time but it might for the larger, more complicated flights.

Everyone has done static ignitor tests and all results will vary, but in my own tests with long leads and estes type ignitors I see the ignitor start with a bit of smoke and then flare up-like a tiny match. That's pretty much how it works with all single 6v launchers too. And it works fine, very reliable. Difference with 12v and relays at the pad is the ignitor goes instantly, almost like a pop, with all the pyrogen consumed at once. Also means much more energy is released in that instant, vs over a somewhat longer period of time. This advantage becomes more significant as more ignitors are added, and with those occasional weak ignitors. Not saying it's better, but it is a difference.

The physical advantage to relay boxes is less wire to run over distance. For just 20 LPR/MPR pads you can save 700 feet of heavy gauge wire or more. You can still have a lot of total conductors running out to the relay boxes for signal and status though, so that may not be a huge advantage. Smaller lighter cables was one motivation for the computer controlled design in my other thread. Reducing total conductors to 7, or three, or none per group of pads is great when we're talking dozens and dozens of pads.

SCE to AUX said:

Looks good , but check the wiring feeding the positive ends of the pad 2 and 3 continuity check LEDs. Looks like they should be extended to the left a bit...

Click to expand...

Ah, you're right. And thanks for catching that. I think drawing a circuit is harder that building a circuit sometimes.

Correction attached.

Dave

I understand the reason for the relay operated pads. My club only operates up to 8 pads, most of the time only tp to 6 and most of them are within 30 to 50'. We have one relay controled pad and that usaly is at 200'.

I made the launch controler to use grounded ext. cords with 2 pads utilizing one cord and split the pads out ot the end using groundes cords from calculators and such. one pad using netural and ground and the other pad using hot and ground. I found out when using a weak battery at 50' it just dont work so I have been using a 800CCA truck/heavy car battery at the controller and it does great.

I just like to keep it simple and useable with out a lot of bells and whissels. even with a 20% off at Radio Shack it was still 100.00 in parts to build.

Pads are not cheep and when you start adding a bunch of relays and other electronics the price goes up unless you make a large order to a cheeper online retailer. I wish I had found Allelectronics when I built the controller.

Well have a good day.

By the way your controller looks great and I just dont have the uptodate knowledge to used digital circuitry any more.

For launchers requiring relays, the cheapest solution is to use standard SPDT automotive relays. They are very rugged, are rated for 40A (and don't fry until about 150A) and in a pinch you can get them at any autoparts store. They cost between $2 and $3 each from Jameco and other electronic supppliers. https://www.jameco.com/Jameco/catalogs/c253/P147.pdf Best of all, the relay sockets are prewired and cheap (~$2 in quantity). All you need is wirenuts to quickly set up the launcher.



Bob