SpudFiles

So heres the plan, I want a shotgun-esque sort of thing. It will have two barrels, and two chambers. I want to know if there is a way to get it so that I can pull the trigger one, and one chamber will discharge into the matching barrel, and then pull the trigger again and have the opposite chamber discharge into its matching barrel.

Thanks!

I assume you mean combustion chambers here....

Not that I know of. You would have to build something up yourself..maybe some sort of spring loaded ratcheting cam wheel that made contact on different electrical points each time you pulled the trigger.

Otherwise, 2 side by side momentary switches may be your best, no muss, no fuss alternative.

Ah, so pull the same trigger twice and ignite each chamber successively?

You can cook something up to do that with a flip-flop and a pair of relays, if you want to use some digital logic.

Or if you're not a geek, try a mechanical approach like starman suggested

Maybe use one of those 3-way toggle switches. (press the top to fire the first one, then it will go back to neutral, and then press the bottom of the switch to fire the second). That would be very simple to wire and still have a good effect.

I had the same question in <a href="http://www.spudfiles.com/forums/multi-v ... html">this post</a>

Still haven't updated that with a better picture.
Because not many people were interested. But I plan to sometime. (or just build it).

I need a circuit similar still.
Since I didn't get the answer I wanted here, I will have to figure it out.

Pretty sure it will require cathode ,diode, anode (and, or, not gates like computers use).

I will ask somewhere/someone but I'll probably explain it "I need to press the button and light this light then press and light this one then..."

If it's only for two you could use a switch On--Off--On with one pole
(single pole double throw) (embarrassing it's SPDT ?)
Connect that to your push button trigger and maybe switch it with your thumb, then press the button trigger again.
Middle position would be safety.

Or place two contacts and push the trigger a little will contact one further will contact other. (Like full-auto if you press it too fast).

Other than that the best way (I am still figuring out) is to use a "Logic curcuit" Pretty simple still, I just haven't figured it out yet. 8)

starman wrote:2 side by side momentary switches may be your best

Why wouldn't you just hook up 4 leads to 1 momentary switch instead of 2 leads to 2 switches. Then you would have simultaneouse firing time and have the 1 trigger he originally wanted.

Seriously, the Switch circuit igpay and myself are thinking of is such a goody, that I don't really like to completely explain it's possible use.

That will attract new laws in another field I am fond of.
It's inevitable that will happen anyway sooner or later,
If I have to explain it you probably wouldn't understand it.

Just check out this whole video:http://www.youtube.com/watch?v=8DRmuljq ... re=related

Pretty self explanatory and this was on "Future Weapons".
I am certain it's possible to build a pneumatic version I explained in my "Multi-valve concept" post I linked to earlier.

Since the trigger is so hard to come by, looks like a component ready to build and sell maybe. 8)

BTW we made a circuit in my micro-computer repair class But that was so long ago I've forgotten. It was just a "counter"I think.

More than two barrels (or bullets)? That's easy enough to do, just use a counter and a demultiplexer.

Or, use a shift register with a pre-loaded "1" and "0"s everywhere else. Each pin is hooked up to a barrel (or bullet), and it will fire each round as it shifts along in sequence.

STHORNE wrote:

starman wrote:2 side by side momentary switches may be your best

Why wouldn't you just hook up 4 leads to 1 momentary switch instead of 2 leads to 2 switches. Then you would have simultaneous firing time and have the 1 trigger he originally wanted.

I didn't gather that he wanted to simultaneously fire is the only reason...otherwise, that's what i would have suggested as well.

Doing this with digital electronics would be fairly easy. Like others have posted, logic gates or a couple of flip-flops. Or, just a shift register. Take a look at http://www.doctronics.co.uk/4015.htm. The "clock" pulses are just the output of your trigger switch. The first circuit shown does exactly what you want except the logic in inverted. You can probably find a simpler shift register with both Q and NOT-Q outputs. Figure the shift register will cost about $1. Add in a circuit board, switch, battery holder, project box and either a power transistor or relay to actually switch the power to the HV circuit and you're probably talking about $10~$20.

Pretty simple except ...

You can't directly switch the HV. Logic circuits will be very unhappy if they ever see the high voltage that creates the spark.

knappengineering's solution is probably the simplest. Just get an on-off-on momentary rocker switch. Rock it one way to fire the first gun, the other way to fire the second gun. http://www.allelectronics.com/make-a-st ... H/-/1.html is almost the switch you want, this one locks in the on positions, you would prefer a momentary switch so it resets to off by itself. (Otherwise you risk accidentally firing the second gun when you switch the first gun's ignition off.) Check Digikey or Mouser, I'm sure they have the perfect switch.

Ok, to clarify, I'm making a pneumatic gun, not a combustion. And second, I plan on using sprinkler valves to accomplish all of this, so the circuitry only needs to be able to withstand 24 volts, (I think most sprinkler valves are 24 volts) So, I was looking at Thunderlord's post, and I came across this. I'm pretty sure this is what I need, just with less inputs, but I have little to no electronics experience, so I wouldn't know.

Yup, that should do it, however you can't hook that directly up to a relay.

You need to buffer the outputs from that IC with transistors or a buffer chip (and special low-power relays in the case of the latter; buffers still can't source more than a few milliamps) or else you'll fry it. The trigger will also need to be debounced or selse you'll fire off several shots at once: http://www.all-electric.com/schematic/debounce.htm

Also, put a reverse-biased diode in parallel with the relay (diode opposes current flow).

But are you planning on using it on 10 different barrels? Because otherwise, a single flip-flop will get the job done just fine.

This can all be a bit overwhelming for someone with little to no electronics experience, so the 2-way toggle switch may just be your best bet.

Simple way of doing all this, just put two doorbell switches one behind the other so when you partially squeeze the front one will push, if you pull harder it will push the first doorbell button into the second, you could keep adding for more barrels. You'd have to build a small compartment for the doorbell switches to just sit in. Not sure if 24V can run two sprinklers at a time though.

igpay wrote:.... So, I was looking at Thunderlord's post, and I came across this

That's the one!!! Yaah!!! That's like the circuit we put together in class years ago. I thought it was a counter.

Some people are confused and think he wants to fire simultaneously.
He wants to fire one and THEN press the same trigger and fire the other.
So one 24v or 27v(Three 9v's) will be fine for pneumatic.

@Jimmy101 or another electronics pro,
Won't an SCR switch work (if the circuit can't handle sprinkler valve current?)?

Thanks 8)

EDIT: @jimmy101, I tried your link for electronics and it didn't work.
But I just clicked again and was re-directed so I'll check that one out now. Thanks.

TurboSuper wrote: But are you planning on using it on 10 different barrels? Because otherwise, a single flip-flop will get the job done just fine.

I'm only using only two barrels for this project, so I guess I can use a flip-flop, if only I knew what a flip-flop was. I wikipedia'd it, but the definition wasn't really helpful. So if someone could tell me what a flip-flop does, and how to wire one up, maybe i can figure use one.

Thanks!