One switch, multiple delay outputs help please

Discussion in 'The Projects Forum' started by matzy, Apr 14, 2011.

  1. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Hi,

    I am trying to find a diagram or help in creating a circuit that uses a 9v input and when operated by a switch it triggers multiple 9v outputs on separate terminals. In principle it should be very easy, but i'm a complete newbie on the electronic circuitry required to do this, I'm perfectly fine with a soldering iron and wiring things up, just need a plan to work from. It doesn't necessarily need to be 9v but its easier as I can simply run it from a 9v battery then

    I'll explain what it is for which should help to clarify what i'm after.

    I am part owner of a paintball company and we are currently organising a game which has our usual pyro effects involved. Usually I trigger most pyro effects using a remote system, or at its most basic using a 9v battery and speaker wire. The pyros are ignited by simply passing them a 6v+ current. For this game I want to be able to flick a switch and have it trigger multiple currents with varied time delays (as low as half a second maybe) which will allow me to create a multiple bang explosion effect instead of the standard press a button and one bang.

    I have looked at many ideas and i'm thinking using multiple 555 timer IC's to do this, I would also need a way to be able to control the delay of each output if possible so I could create something like the following


    Output 1: Delay 0 seconds
    Output 2: Delay 0.1 seconds
    Output 3: Delay 0.5 seconds
    Output 4: Delay 1 seconds
    Output 5: Delay 1.2 seconds

    If its still not clear what i#m after please ask me and i'll try to explain a little clearer.

    Many thanks
     
  2. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    You could use a counter scheme with a 555 timer supplying 0.1 second pulses. A binary ripple counter with appropriate gate decoding could supply what you need.
     
  3. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Hi Bill, thanks for the reply. I just about understand the theory behind how that would work but wouldn't have the slightest clue how to start making it. Only question is if it is set at 0.1 second pulses how could I have it trigger the pyros at slightly different intervals?
     
  4. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    You would use different outputs from the count decoders. An output decoded for 1 would be 0.1 seconds. An output decoded for 5 would be 0.5 seconds. An output decoded for 8 would be 0.8 seconds. The decoder circuit would select only specific counts to be allowed through to the individual pyros. The drawing I'm attaching is CONCEPT ONLY. The Pulser to the left would be your 555 timer. The 75LS193 is a binary counter (Counts to 15 and starts over). The 74LS156 is the decoder. For each count step, the output will switch from the previous to the next output line. You would then have the flexibility to select any increment of time with the time between steps controlled by the pulse rate of the 555.
     
  5. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
    141
    If I was faced with such a task, I'd use a PIC microcontroller. You have five time delays that you want to provide, so you'd get their times from five pots and use five input lines to read the voltage on each pot. These analog values control the delay (you have time resolution of about 1 part in 1000). Then there's one analog input to monitor the push button switch to start things. Finally, five outputs drive a bipolar transistor or MOSFET to turn the voltage on to each load.

    One reason I'd use the PIC approach is that it's very typical for people to change their minds about how things must operate (i.e., the design changes as you get more familiar with the problem). The microcontroller approach lets you change behaviors a bit easier because things can be done in firmware.

    Assuming you have a decent power supply, the components required for this are pretty much the pushbutton switch, pots, microcontroller, and some MOSFETs like the IRLD024. You'd probably want to sprinkle a few bypass caps around and probably put some 1k resistors inline to the gates of the MOSFETs.
     
  6. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    wow guys, thanks for the responses. Bill, I understand how your concept would work, and to be honest I think it would do the job perfectly by the way you have described it. I can get the 555 timer chip from Maplins here in the UK but couldn't find any of the 74LSxxx components, unless they are listed as something different here. I would be very interested in progressing with your idea as I like the simplicity of it, plus i'm sure I am more than capable of constructing the end project. For testing is it possible to have an LED on each output to light when triggered or will that require more circuitry?

    The PIC controller option does sound good, however i'm sure that we will not be needing to change anything once we can ignite the pyros in simple succession, its quite possible that once the device has been built and used, it may never be used again, or maybe once a year when we organise our game.

    Really appreciate your input anyway guys, i'm feeling quite positive that what I want to achieve is now a possibility.
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
  8. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Thanks Bill, I've used CPC many times before who I believe are part of the farnell group.. I found them on CPC but Farnell's site is a little cheaper !! Time to change supplier :)

    The concept circuit you've done, is that useable? If so, is it worth me buying the components and starting a build?

    I'll be using these loudspeaker plates to connect the outputs to, and then just connecting the wire from the pyro into them.

    http://cpc.farnell.com/_/av20578/loudspeaker-plate-2-terminal/dp/AV20578
     
  9. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    The output of my concept will be logic level (0-5VDC) with little drive current available. Not knowing what is needed for the pyro to fire, you probably need some form of current driver. Again, this is a concept and I am a little reluctant to go further since you are playing with explosive and potentially dangerous devices. I think I have provided a means for you to generate pulses that are spaced the way you requested. Others may jump in with more information on how to actually use these signals to fire your pyros.
     
  10. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Hi Bill, I fully understand your concerns regarding the use of the pyrotechnics. Rest assured, there is no malice, or intention to harm when using these devices. I am an owner/partner of a paintball sales company (i'll send you details to verify in a PM) and we are currently organising a game in July themed on the Resident Evil movie. We have used the pyrotechnic effects on many occasions but it is always single bangs, this time I wanted to do something a little different by having a sequence of explosions to add a further depth of effect, and all the pyros are placed well away from any gameplay area as safety is a major concern that we pay close attention to.
     
  11. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    What kind of igniter? Current/voltage requirement?

    I still don't have a fuzzy feeling about this. Not doubting the end usage, just the end
    result.
     
  12. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
  13. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Here is a more complete system. Complete isolation between the logic function and the actual pyro power seemed to be essential for safety reasons. With the Arming Switch open, relay activation could be observed to verify proper sequence. The one drawback is that the "Instant" relay will stay active until the switch is opened again. Of course additional parts could be added (a gate) to eliminate that problem. On the diagram a timing diagram, you can see the oscillator running free at the bottom. The top trace represents the "RUN" function. When switches to LOW, the timing starts. The flag numbers correspond to the trace numbers.

    On EDIT: Just realized I didn't put pull up resistors on output of inverters. Probably needed to turn darlington transistors on full.
     
    • Pyro.jpg
      Pyro.jpg
      File size:
      176.2 KB
      Views:
      42
  14. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Just a very quick reply as i'm about to head of for work, I have emailed our supplier for the pyros to get confirmation of the current/voltage requirement and I believe the ignition system is standard e-match terminated. I'll be back tonight and will hopefully have the information needed.

    I looked at the product link you sent, that is perfect for what I want to achieve, however, far from cost effective as it'll very rarely be used, plus I would get so much more satisfaction out of creating my own unit, for example, within the game we are using the Resident Evil T-Virus vials as point scoring items, we could have bought these at a cost of something in excess of £50 GBP each, instead I made my own from acrylic tubes and coloured acrylic rods..
     
  15. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    I received a reply from our pyro supplier which was as follows

    "The igniters are fired with just 6V with the 4 x AAA batteries in the remote detonators and although they are more commonly known as 9V maroons it is actually the Ohms that are the important factor and the higher the Ohms the better. I am not sure what the minimum voltage would be but historically people use a small 9V battery"

    Hopefully that was of some use.
     
  16. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    In that case, the latest concept drawing should work. I did an internet search and found a unit someone had made that used MIDI music to sequence the firing of the charges. I saw how he isolated the actual logic from the firing current with relays, therefore the diagram in post #13. Good luck with your project!
     
  17. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    I found that one too, with 128 channels!! Certainly much more than we need. Many thanks for your help and concept, I am going to go ahead and start run with the project and will keep you updated once I start. Do you mind me asking questions if something is not quite clear still?
     
  18. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    No problem. Just so you know, I'm a maintenance type, not an design guru!
     
  19. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    I realized that I didn't attach what I had found about the sequencer I that used MIDI. Here it is.
     
  20. matzy

    Thread Starter New Member

    Apr 14, 2011
    14
    0
    Hi Bill,

    I was putting together a list of all items that I needed to buy for this project when someone recommended the Kingdom 10 Cue Sequencer/Stepper system. I checked the unit out and it is perfect for what I am trying to achieve, and at only £65 its not far from the cost of me building this project, plus its programmable, has 10 channels.. needless to say i'm going to invest in this unit instead. Thanks for taking the time to help me with your ideas and schematics though, it was very much appreciated.

    There is another, much easier project that I want to achieve though which i'll put up in a new thread in a minute.
     
Loading...