Electronic Fireworks Firing Panel

[faithblinded]

Ok so I decided to start a new thread since I took the other one so far off into this topic.
Other thread: Help with Component Retailers !?!?

Based on all the great advice I've been given here, I now have the joy of redesigning my circuit. I really don't want to do it on paper. What is a good easy to use program to design schematics visually? Preferrably not completely text based input. I need easy to use. Price doesn't matter (yo ho ho).

If I can do that I'll post it here so you guys can really tear it apart and find the flaws.

Another question I have. I'm using 2 12V batteries in a series for 24V. When figuring out what resistors I need for my LED's, what voltage should I base my math on? Should I equate based on the high end of the operating range, or tha average? 24V or 26-27V?

Any ideas on the best prices for LED's with chrome holders(5mm)? I need red and green...


li_gangyi : I used that power supply designer you linked me to and worked out a supply with parts they had in stock that would turn my 24V into 12@2A. Pretty sweet little program they have there. The problem I see is I don't know if I can solder that small at this point. I'm still learning lol. IC's scare me, and I didn't even know what some of the components listed were. Granted, the sytem the software designed only had about a dozen components, which is sweet. And they would put it all together in a kit for like 30 bucks. I think a simple 12V battery will be the cheaper way to go. This year at least. Next year I'll have to make some improvements, so that could be one. Plus I don't like building things I don't understand. I didn't really understand how that PSU worked. Neat little site though.

[Variac]

OK , you have 2 batteries in series to get 24v.

If you are using the 12 volts for low current stuff, like LEDs and the power for relays, just use wires from the positive and negative of ONE of the batteries in series. You can leave them hooked up for 24v, just tap one battery for 12. Doesn't hurt a thing except drains the battery thats hooked to the 12 v stuff a little faster.

[li_gangyi]

yupz...I actually gave him a link to the National's SMPSU design webby...you can try the through hole parts...but if you really wanna go the cheapie way the 12V using one battery trick will work well...so what is the main thing the the control panel has to give out?? Voltage...Current?? some specs posted here will help us to help you...lolx

[faithblinded]

Originally posted by Variac
If you are using the 12 volts for low current stuff, like LEDs and the power for relays, just use wires from the positive and negative of ONE of the batteries in series. You can leave them hooked up for 24v, just tap one battery for 12. Doesn't hurt a thing except drains the battery thats hooked to the 12 v stuff a little faster.

I didn't know I could do that!

The only thing the 12V will be used for is to switch relays on and off for the 24V signal to the firing slats. It will allow me to user lower rated(and much cheaper), rotary switches and pushbuttons.

The LED's will be in the 24V circuit though, so I know I have to use resistors for them.

I'm working on making my schematic in CircuitMaker 2000 right now. I wish it had more components. Is there any other similar software I can use?

[faithblinded]

Originally posted by li_gangyi
so what is the main thing the the control panel has to give out?? Voltage...Current?? some specs posted here will help us to help you...lolx

The main thing the panel has to give is voltage. It's travelling over more than 100 ft of 18 guage wire, and I need it to be responsive. The electronic matches the system fires only need about 40-60 mA to fire, but the higher voltage makes em fire quick. Especially when firing numerous matches at once, which involves numerous runs of 100ft+ 18ga wire.

[li_gangyi]

ok...you'll probably need a 2K resistor to limit the current safely for each LED...then a simple lash up for the controller...since you only need a few mA to fire the cartridges (I suppose) why do you need a relay (which might slow the response)??

[faithblinded]

Having a very hard time finding inexpensive 24V rated rotary switches and pushbutton switches. This system has the ability to fire up to 6 cues from one button, and obviously I'll be able to push more than one button at once. This will increase the amperage going through whole the system(I think?), particularly the rotary switches and pushbuttons. Please tell me I'm wrong and It probably won't really ever go over 3 amps on each rotary or pushbutton, and I'll scrap the relays.

I've been having my doubts about whether or not I was way overestimating the current draw of this system. I just don't want to be a victim of blown components. But I don't want to be a victim of overkill(and overpay) either.

[li_gangyi]

I suppose you wouldn't even overshoot 2A...I see what you mean now...set a few rotary switches...press a button...boom boom boom...just like a crazy movie (hehex) you can try looking for "standard" rotary switches...the current shouldn't fry em...

[faithblinded]

Ok well I'm going to finish my schematic with the original design then, and I'll post it for judgement, lol.

[pinkmouse]

If the matches you use are the same as we use in the UK, ( I assume they must be, usual Chinese?), then I used to use 48v for the firing circuit, it gives a lot more leeway for long cable runs with cheap wire.

A mate also made a 24V version with 10000uf caps that was great for slow rate, but large numbers of simultaneous firings.