Firework Controller CDS- Capacitive discharge system - Page 1
Forum section: electronics / beginners

author: jfiliaul
author_rank: Newbie
timestamp: December 15, 2014, 01:55:57 am
content: Hi eevblog smarties... i need some help!!!!!!! Im trying to design and build a firework controller/launching system.. I am a licensed pyro in Massachusetts (USA) and I need some help with the firing circuit itself! Im using the Fireone modules as an example and I am having trouble with how to build the capacitive discharge circuit. If you go here:http://www.fireone.com/hardware.htmand look under firing modules you will see the following:Output LevelsEach output line (cue) of a Firing Module can independently supply a nominal voltage of 24 volts at 5 amperes of firing current for 12.5ms.Regardless of the distance from the control panel, each and every FireOne™ Firing Module has the capability to provide the same rated current into each cue. This is possible due to FireOne's proprietary capacitive discharge power system.Each Firing Module has an independent capacitive firing circuit that supplies sufficient power to enable every firing module, regardless of location, to fire every cue simultaneously into a full complement of electric matches. This means that each firing module can supply five amperes of current into each cue circuit, simultaneously, generating a total peak current of 160 amperes.This robust output circuit is capable of firing multiple electric matches or activating relays or other tasks as may be envisioned.Could someone help me come up with a robust circuit that is capable of doing this. Including the part numbers??? Each modulde is capable of firing 32 cues with multiple e-matches per cue...The other trick to this is that the module gets its power and data over an 18 guage 2 wire system... how can I use the 2 wire system to send power and data?? If anyone is interested in helping me create this, that would be awesome, I will cut you in on the sales! I am a software engineer and also dabble in electronics... I am class 3 certified in soldering and know a good amount about electronics but this is a little above my head as far and calculations and such... I can take care of the communications between the hardware and software and basic electronics layout and design! Thanks guys!!!P.S. here are the specs on the e-match. We use Daveyfire IgniterModel Bridgewire Resistance (Ohms) Max No Fire Current (Amp) Min All Fire Current (Amp) Ave. Firing TimeSA 2000 N28BR 1.6 ±0.3 0.20 0.3 2ms @ 1 Amp 1ms @ 3 Amp

author: Marco
author_rank: Super Contributor
timestamp: December 15, 2014, 04:31:33 am
content: I assume they just charge a ~2700uF capacitor to 24V, sounds about right for 5A for 12.5ms. you could make more complex circuits to generate more load independent pulses, but I don't really see the need (it will supply more like 10A for a couple of ms to a single one of your e-match's, but it's still going to blow ... you could wire a few in series or parallel and they are still going to blow). As for combining power and data, you just use something like RS-485 with DC-balanced encoding, that way you can AC couple it to the cables, you then connect/tap power from the lines through a common mode choke (say ~100 mH, so it can effectively block signals at a couple kHz).Why do you think you can undercut the many companies on the market already? Especially after factoring in the cost of proving you did all the due diligence in making sure your design was safe so you wouldn't get sued into oblivion if something goes wrong?