55 replies to this topic

[CCH Concepts]

Recharge time between ques. Say you have 30 cues that you want to fire sequentially within a couple of seconds you are buggered. This is not important if you only have one cue like when blasting (OK maybe a few are used but they are independent channels with their own charging circuits).

So how much of your consultancy fee do we get for the info?

each output channel could have a charged capacitor, as there would only need to be one dc-dc converter and a common rail.

as for consultancy fee its negotiated at the time. this is a new business and i have only worked on 2 projects so far. in both instances the agreement has been for me either to supply them long term afterwords or to be joint in development for long term. in these instances i haven't charged for my initial work.

in the case of just helping someone to develop a product they wish for personal use or to sell and I'm only in on the start it would very much depend on the complexity and man hours involved. but i would quote at job rate rather then hourly.

i know they is a bit vague but its not a simple question to answer.

[digger]

each output channel could have a charged capacitor, as there would only need to be one dc-dc converter and a common rail.

as for consultancy fee its negotiated at the time. this is a new business and i have only worked on 2 projects so far. in both instances the agreement has been for me either to supply them long term afterwords or to be joint in development for long term. in these instances i haven't charged for my initial work.

in the case of just helping someone to develop a product they wish for personal use or to sell and I'm only in on the start it would very much depend on the complexity and man hours involved. but i would quote at job rate rather then hourly.

i know they is a bit vague but its not a simple question to answer.

I charge £50 to £75 per hour depending on what I think the job will take so what do I get tonight ?

[digger]

One small thing though. I hope you check your grammar and spelling on your reports as it is still very bad on here (and mine is bad, being a chemical engineer, maths is my strong point not my English).

[CCH Concepts]

I charge £50 to £75 per hour depending on what I think the job will take so what do I get tonight ?

there an idea, consulting via a forum and charged by the hour for a night work. haha. would make millions lol.

on a serious note until i have a few good projects under my belt to showcase i would probably be charging a few hundred for a weekends work. once the business is established that will change. as I'm sure you will note i said weekend not week, because in the current climate i cant take the risk of leaving my day job to work on my business full time.

[CCH Concepts]

One small thing though. I hope you check your grammar and spelling on your reports as it is still very bad on here (and mine is bad, being a chemical engineer, maths is my strong point not my English).

ow yes, ms word is my friend. plus i have a girlfriend that is very good at english who proof reads stuff for me. when i the business is strong enough to do so she will be the secretary.

[Arthur Brown]

http://www.blue-room...ndpost&p=301077

Links to two simulations of a parallel cct and shows that there are differences in the firing current and that some igs may not fire first time, though if the power stays on, as one ig fires the next ig will get enough current to fire and so on, til there is a short.

Those figures were picked as typical for stage pyro! For fireworks all the cable lengths will be longer so the resistances will be greater, and current less.

[digger]

http://www.blue-room.org.uk/index.php?s=&showtopic=35806&view=findpost&p=301077

Links to two simulations of a parallel cct and shows that there are differences in the firing current and that some igs may not fire first time, though if the power stays on, as one ig fires the next ig will get enough current to fire and so on, til there is a short.

Those figures were picked as typical for stage pyro! For fireworks all the cable lengths will be longer so the resistances will be greater, and current less.

Interesting. Yep it follows Kirchoff's circuit laws.

However if I was connecting in parallel I would bring all of the leads back to the cue which would prevent this problem from happening as each is an independent circuit limited by the total deliverable current.

I guess we had a different idea of parallel connection in our minds. I would have never even considered that method for the reasons demonstrated in that SIM.

Edited by digger, 01 October 2009 - 11:33 PM.

[Arthur Brown]

Whichever style of parallel, 1/ it follows Kirchof's laws, and 2/ it draws a huge current. There are numerous firing machines that will not supply 20A even for a 20millisecond pulse.

If firing matters, then it's worth checking that it will work. Brian of the ASP created those sims to relate to stage pyro situations where 10 - 50m of wire might be used. If you insert better values for the fireworks industry with longer distances then the probability of firing and the reliability of firing depend on all the variables.

If you have a long wire with lots of cues then the first few will fire if the supply is adequate, THEN and continuously, the next few cues will fire as the current becomes available down each leg from a continuous power supply.

[digger]

Whichever style of parallel, 1/ it follows Kirchof's laws, and 2/ it draws a huge current. There are numerous firing machines that will not supply 20A even for a 20millisecond pulse.

If firing matters, then it's worth checking that it will work. Brian of the ASP created those sims to relate to stage pyro situations where 10 - 50m of wire might be used. If you insert better values for the fireworks industry with longer distances then the probability of firing and the reliability of firing depend on all the variables.

If you have a long wire with lots of cues then the first few will fire if the supply is adequate, THEN and continuously, the next few cues will fire as the current becomes available down each leg from a continuous power supply.

Yep

I go for large current. Actually in practice a combination of 2 plus some serial to current limit whilst making the most of the available drive current to allow the maximum number of concurrent ques to be fired.

EDIT to add

If required as I would not generaly need a great number of igs from 1 que

Edited by digger, 02 October 2009 - 07:48 PM.

[werewolf-one]

Somewhat off topic I realise, but for your information technoboot-uk has an item that may interest you.

Ebay Item 270463173910

Shrike rocketry caving pyro controller / initiator L3A2

I came across it during my regular trawl through my saved sellers.

Cheers

Edited by werewolf-one, 03 October 2009 - 01:48 AM.

[CCH Concepts]

Somewhat off topic I realise, but for your information technoboot-uk has an item that may interest you.

Ebay Item 270463173910

Shrike rocketry caving pyro controller / initiator L3A2

I came across it during my regular trawl through my saved sellers.

Cheers

yer saw that myself. looks a bit bulky though