stgtech Posted July 20, 2007 Share Posted July 20, 2007 Hey all, before I go on I want to stress that im well aware of the dangers of pyrotechnics, ive built my own pyro launchers before this, all safely, and I plan on keeping it that way. I mainly build these for sheer fun and rarely actually use them, and when I do, it is outside, away from people. This current board is rather complicated, as it is manual, as well as computer controlled. A brief specs: the controller is 16 channels. Powered by 12V DC. The computer board is a DC-16 by EFX-TEK, which is run by Vixen software. The 16 outputs trigger 16 12v relays in series with 16 toggle switches so that the computer can only fire armed channels. There is an on-on toggle switch that selects between the manual and auto modes. when in manual 16 push buttons trigger the channels. There is also a deadmans momentary pushbutton, so that neither the manual or autmatic modes will work unless it is held down. There is also 16 continuity checks in both automatic and maunual. These use and LED and a 1K resistor bypassing all switches but the matser power to determine if there is continuity in the pods. Ok now my main problem is the wire to go from the control box to the pods. Originally I was planning on 4 or 6 pin XLR because it is uncommon and cannot be confused, however, it is also very expensive (for a homebuilt project experimentation). So my next though is CAT5E. This cable can be found to be rather durable and has 8 lines. my plan to use it safely since they are so close was have the common on pin 1, skip pin 2, then use 3-8 for 6 channels. Any comments about the cable or the whole thing would be appreciated however please do not tell me I am in over my head....it is unsafe...to discontinue worl...etc. Thanks very much for any help you may offer. I attached the schematic.http://i69.photobucket.com/albums/i58/stageprop/pYRObOARD.jpg Link to comment Share on other sites More sharing options...
Brian Posted July 20, 2007 Share Posted July 20, 2007 RJ45's are a bit flimsy, the usual point of failure being the latch. How about 'D' connectors, maybe the 9-way version? Or Burndy 'QM' connectors? Link to comment Share on other sites More sharing options...
Jivemaster Posted July 20, 2007 Share Posted July 20, 2007 The final circuit is important! Look at the number of igniters you want to fire in series, then do the Volts, Ohms, Amps, calculations. igniters have a typical resistance and typical firing current according to supplier and type. Obviously at close range a good 12v battery will fire anything, but do consider the voltage drop due to cables and connectors. Using a commoned return wire may be false economy, as if each of the channels want to send their current down the return wire simultaneously then the IR volts drop could prevent reliable firing. I personally dislike multicore in the vicinity of pyro as one good spark could cause damage. Use a multicore so far then break-out into separate disposable cables, -likely bell wire. Something like RS stock number 177-677 or 449-269 could bring you towards standardisation with commercial devices. There are robust multipole connectors including the Bulgin Buccaneer range and flimsier ones such as the D series.. I have seen the 25pin D-connector suggested for use for 12 circuits with a live and return for each, esp as 1-1 wires parallel cables can be bought cheaply. Keep checking! the effort you put into the controller will be wasted if you spoil the output lines. Also please check the 100% no fire until 100%fire as needed rule. It really must be right with pyro. Join the Assn of Stage Pyro ( www.stage-pyro.org.uk ) as a member you get lots of circuits and calculations available to you. Link to comment Share on other sites More sharing options...
p.k.roberts Posted July 20, 2007 Share Posted July 20, 2007 Aaron, I'm just a bit confused (nothing new there!) - are you a) running a separate cable from the control point to each pod, b)running a multi-core cable from the controller to a stage breakout box and then from that an individual cable to each pod or c)running a multi core cable 'daisy-chained' through the pods? Link to comment Share on other sites More sharing options...
gareth Posted July 20, 2007 Share Posted July 20, 2007 Apart from their flimsiness (unless you use the Neutrik version in a metal shell), I'd also be a little worried about moisture ingress into an RJ45 when used outdoors. We have a 120-channel home-built diring system which uses QM-series circular multipole connectors, and they've served us pretty well for a good few years now. (This system is about to be replaced with a Fire One system, though.) Link to comment Share on other sites More sharing options...
Johnno Posted July 20, 2007 Share Posted July 20, 2007 Join the Assn of Stage Pyro ( www.stage-pyro.org.uk ) ... That website tells you everything about the ASP except how to join! Well, I can't find it. Link to comment Share on other sites More sharing options...
Jivemaster Posted July 21, 2007 Share Posted July 21, 2007 The association is for people who have done a one day pyro course - see "next pyro course" http://www.blue-room.org.uk/index.php?showtopic=18138 Which Lincoln updates. Link to comment Share on other sites More sharing options...
stgtech Posted July 21, 2007 Author Share Posted July 21, 2007 hey everyone, thanks alot for your replys. I see alot of you mentioned different connectors most of which ive never heard of. I will most definetly look into all your suggestions. For the CAT5 cable it would run from the controller, to the pod, then daisy chain. However, I never thought of the breakout box idea, which I rather like as well. Since I can get CAT 5 cheaply my plan was to find some quality stuff, then simply cut off the connectors and use Neutrik CAT5 connectors which I hear are very good. Thank you all for your reply's and I will look into all your connection suggestions. And JiveMaster, I will definetly take the multicore to a breakout box into deep consideration....Why didnt I think of that? :D I assume nobody saw any potential major flaws with the circuit? Ide rather find out now then with a voltimeter cause then I need to fix it after :( Aaron Ok well I checked out both the Buccaneer and QM series. I had trouble finding anoything on the QM. As to the Buccaneer it looks very nice especially the 400 series. THe also had an ethernet similar to the nuetrik one. My two problems are: Woudant I just be better off with nuetrik connecters as they ar more commonly available? (to me atleast) and basically the same?So in that case, if I were to use the RJ-45 Nuetrik would that be good? and if not the 6 pin XLR nuetrik? what type of cable do I use for the 6 pin XLR nuetric? recommendations? Aaron Link to comment Share on other sites More sharing options...
Jivemaster Posted July 22, 2007 Share Posted July 22, 2007 Please be aware that it is illegal for anyone to buy or keep pyro until they are 18. Please dont get into trouble before then as it will make lawful posession later very difficult. Link to comment Share on other sites More sharing options...
stgtech Posted July 22, 2007 Author Share Posted July 22, 2007 thank you for that, I was unaware, although I assume I would have found out before buying (I hope). Are my parents allowed to purchase/ hold this for me? Link to comment Share on other sites More sharing options...
Andrew C Posted July 22, 2007 Share Posted July 22, 2007 Please be aware that it is illegal for anyone to buy or keep pyro until they are 18.Although Stgtech hasn't filled in his location on his profile, I believe that he is not UK based (from a $ price in another thread). He may, therefore be quite legal in buying pyro. After all kids have guns in some countries at quite stupid ages... :D Link to comment Share on other sites More sharing options...
scjb Posted July 22, 2007 Share Posted July 22, 2007 I notice from the circuit diagram that you are using a large number of relays. I would be very tempted to swap these to solid-state relays. I know that they can be significantly more expensive, but they eliminate the potential for unintended initiation from rough handling or shock\vibration. I appreciate that in your application you have isolating switches for each channel, the desk is only armed just prior to firing, the desk is away from the mortars etc... Just my opinion. Have fun and stay green. Link to comment Share on other sites More sharing options...
Jivemaster Posted July 22, 2007 Share Posted July 22, 2007 snip...Are my parents allowed to purchase/ hold this for me? Assuming now that you are US based (yes I've just seen your $ post also!) you will have all the State and Federal laws to identify and comply with. Spend some time looking at your legal position in your location. Link to comment Share on other sites More sharing options...
zonino Posted July 22, 2007 Share Posted July 22, 2007 Some states also require you to hold a pyro license (California for example) Link to comment Share on other sites More sharing options...
stgtech Posted July 22, 2007 Author Share Posted July 22, 2007 I notice from the circuit diagram that you are using a large number of relays. I would be very tempted to swap these to solid-state relays. I know that they can be significantly more expensive, but they eliminate the potential for unintended initiation from rough handling or shock\vibration. I appreciate that in your application you have isolating switches for each channel, the desk is only armed just prior to firing, the desk is away from the mortars etc... Just my opinion. I was originally planning on SSR however I read an interesting little article about how SSR's have been know to be triggered on small variances in the current as well as other inopportune times hence discouraging me from that route. at least with physical relays they just wont switch or they get stuck. as to the safety measures...I intend to institute all these measures however can you explain more about the isolating of the switches? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.