Pete Firth
New Member
Hello all, Sorry I'm a bit of a neewb (this is my first post), I have a fair understanding of electronics and circuits but when it comes to resistors capacitors micro controllers etc I'm totally out of my depth!
I'm trying to work out the circuit for what I believe (maybe showing my ignorance!?) should be a fairly straightforward project. and I'm hoping that some of you may be able to help with the circuit design/planning.
The Dream: a simple sequencer that is triggered from an electrical pulse (sent from an existing firing system) triggers a sequencer, i.e. an electric pulse incoming, and on each subsequent input pulse advances to the next output, each output is a pulse of current that goes to an 'electric match' basically a resistor that gets overpowered and burns up igniting a firework fuse or lift charge.
So similar to an led counter circuit where each press of a button lights a different LED, just in this case theres an led and a current sent to the ignitor to fire the firework connected.
The system will be powered by 2 x 9v batteries (18v), there should be a continuity test function with an LED to indicate a complete circuit, and an LED indicator for each output pulse (can use the same LED), the counter should also reset to 0 on power cycle, in theory a simple CD4017 decade counter should do the trick as I only want 6 or 10 queues / channels on this system, the continuity test will need to be at less than 15mA, the ignitors are not sensitive to current direction, and once fired the circuit is broken, however some sort of dead short protection is probably a good idea.
So, its a stand alone system with its own 18v power supply, when switched on it should show/indicate if there is continuity on each of the output circuits, the trigger is a pulse of current from a separate system, each time an input pulse is detected it should send current to an ignitor in sequence [pulse #1 (p1) fires queue 1(q1), p2 fires q2, p3 fires q3 and so on..].
Its worth noting that it should not include any mechanical relays etc, as in a failure this could cause a dangerous occurrence! these sort of systems often employ fets (but I'm not entirely sure I understand what they do..
I hope thats enough information to get started? I think I can get my head around circuitry that would make this work but I'm clueless as to what resistors capacitors etc I would need to protect the circuit and make it function reliably.
Any help would be much appreciated!
I'm trying to work out the circuit for what I believe (maybe showing my ignorance!?) should be a fairly straightforward project. and I'm hoping that some of you may be able to help with the circuit design/planning.
The Dream: a simple sequencer that is triggered from an electrical pulse (sent from an existing firing system) triggers a sequencer, i.e. an electric pulse incoming, and on each subsequent input pulse advances to the next output, each output is a pulse of current that goes to an 'electric match' basically a resistor that gets overpowered and burns up igniting a firework fuse or lift charge.
So similar to an led counter circuit where each press of a button lights a different LED, just in this case theres an led and a current sent to the ignitor to fire the firework connected.
The system will be powered by 2 x 9v batteries (18v), there should be a continuity test function with an LED to indicate a complete circuit, and an LED indicator for each output pulse (can use the same LED), the counter should also reset to 0 on power cycle, in theory a simple CD4017 decade counter should do the trick as I only want 6 or 10 queues / channels on this system, the continuity test will need to be at less than 15mA, the ignitors are not sensitive to current direction, and once fired the circuit is broken, however some sort of dead short protection is probably a good idea.
So, its a stand alone system with its own 18v power supply, when switched on it should show/indicate if there is continuity on each of the output circuits, the trigger is a pulse of current from a separate system, each time an input pulse is detected it should send current to an ignitor in sequence [pulse #1 (p1) fires queue 1(q1), p2 fires q2, p3 fires q3 and so on..].
Its worth noting that it should not include any mechanical relays etc, as in a failure this could cause a dangerous occurrence! these sort of systems often employ fets (but I'm not entirely sure I understand what they do..
I hope thats enough information to get started? I think I can get my head around circuitry that would make this work but I'm clueless as to what resistors capacitors etc I would need to protect the circuit and make it function reliably.
Any help would be much appreciated!
