Pyro Wire.

[Jivemaster]

I understand there is a significant and lawfull amateur fireworks scene in the US. Please search them out (PGI is one group) and keep the interest, and keep it lawfull. Learn all you can and keep the theatre pyro in mind.

[scjb]

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?

 

There have been a number of reported incidents whereby firing systems utilising relays have fired channels when subjected to shock (including alleged instances whereby relays were used in field boxes and ground-shock from the mortars was enough to jolt the relays to closed). I appreciate SSR's have their quirks also.

 

Regarding isolating switches, I was merely refering to the fact that your circuit diagram already includes SPST switches on each channel, and therefore for an unsafe event to occur through a relay being inadvertantly closed, the switch would also have to be shut... and therefore the channel was presumably already about to be fired... and therefore the worst case scenario is something being fired safely off-cue. That's an appallingly constructed sentence, but you get my drift! I wasn't having a pop, just noting that you had already included good practice in your design.

[stgtech]

great thank you. I wanted to ensure that due to the fact that computers enjoy being mean and doing things they shoudant :) that should it decide either by its own or an operator error to fire at the wrong time either the deadmans switch, or the arming toggle switch will prevent it from firing. glad you support the idea. Pyro is taken far to lightly and anyone that thinks a launcher should be set and forget is crazy.

[Jivemaster]

Start here www.pgi.org/ and make friends and skilled acquaintances your side of the pond. The types and ratings of people and devices in the UK may not help you, and our knowledge of US pyro and firework law will be less than theirs. In either place one false move and you risk being brushed against the anti-terrorist legislation most uncomfortably.

[lonfire]

hi,

there is a slight "bug" in your circuit.. although will only happen in certain circumstances..

 

if you for example have it set to manual fire mode, and press channel one, and at the same time the relay switchs were all closed and the relays were all switched closed (or just the channel you are firing and another one), you COULD fire all channels (or the ones that are swiched on by the relays).. this is due to current flowing back up through the relays around the common + and back down the other relays to the caps..

 

like I said, its unlikely, because you'd need to leave the relay switchs on AND the relays would need to be switched on... but its still a bug and could happen.. to fix it you'll need to add diodes after the relays (and push buttons) to stop current flowing the wrong way around the switching (push buttons or relays) circuit..

 

rgds

chris

[stgtech]

wow. thank you very very much. that is precisiely the reason I posted the circuit. I appreciate you spending the time to look it over and will most deffinetly add in a diode. do you have any suggestions?

 

~aaron