neosaint99

How much of the xmas light tip do I take off?
if its like number 2 then jabbing it into the bp wont fill it
if its like number 3, then how do i get that much off without breaking the glass?
usually once i get halfway down the conical part at the tip the glass gets real thin and just crumbles in my hand

Hi guys,
If you check the packaging, you will be able to calculate the operating voltage of the bulbs.

Basically, a set of 50 will require about 5 volts each at 240v mains supply and a 9 volt battery will blow it.

However, a 100 set will only need about 2 1/2 volts/bulb and the same battery will fire it very quickly.

Those with lower voltage mains supplies will be even better off.

Just remember that the filaments are fairly delicate and you MUST put your powder in gently.

Sandy

hi sandy

i was trying those xmas lites you were talking about
once i get the tip off, there is a real tiny hole...about an mm in diameter...or thereabouts
how do you get the bp in there?
i keep getting more on the table than into the lite bulb

any secret tricks you can share?

xmas tree lights?...you dont say....
sounds like a plan!

i'll try that out first thing tomorrow
i'm sure i have some lights somewhere around here
do they work with regular home made bp?
coz i'm from malaysia
so anyting i use has to be made myself
cant buy nuts even if your life depended on it...zero available pyro stuff in the market
if home made bp dont work, could you give me the composition of a more suitable powder?
oh...and what voltage is required to blow these babys?...hehe

tq!

I've been trying to make cheap ignitors
What I'm currently working with is reletively cheap
I costs a few cents each and the flash is great
What I do is tape two regular safety matches together
Then strip about 15cm of twin bell wire (the 5A rated stuff)
That leaves me with (I've never really counted)...i guess 20 or more strands of fine copper wire
I use this as they are mighty easy to solder
After this, I twist a single strand of the copper wire around the match heads
(I use two matches to get a better initial flash...you can try it with one...it usually works also )
Next I strip about 30-40cm of Cat5 wire
That gives me 4 pairs of wire (already twisted! )
I solder this to the two ends of the strand of copper wire that is already wrapped around the match head
Then tape the Cat5 wire to the base of the matches
After that I make a BP paste
(I actually stumbled upon this when I accidentally added too much solvent to my propellent mix...hahaha)
As a binder, I use shellac
Its cheap, and spirit dilutes it great
My BP paste is about the consistancy of toothpaste
I usually make a quater of those disposable plastic party cups of it
It can coat about 40 or 50 (depending how thick you coat it)
But if you are making lots, you'll have to add solvent to is as it thickens
Then you just hang it up to dry over night
But the next day, it has formed a hard shell around the matches
I estimate that they'll cost about 5 cents each...maybe less
Not to mention I generally use Cat5 wire that people throw away as faulty
(usually just 1 wire is broken in the entire length...so at worst, only one of my ignitors wont fire)
The mathces are real cheap...a few cents for a whole box
The tape I use is regular paper tape a.k.a masking tape
Thats like a buck or two for a 1 inch roll
Well, thats it then!
Hope this can be of some little help to you...

Is part of your work to do a CE/peer review. If so I'd be willing to help.
A few points;

Perhaps using a different plug would be a good idea, using an IEC connector will only tempt people to plug it into the mains. Failing that you could build in some form of mains detection and auto shut down to protect the equipment and user.

You could use a semiconductor output stage instead of a relay, they tend to be more reliable and safe. High current switching tends to knacker relays.

The audio warning could be put into a loop including the e-match. this would give a real warning signal telling you that all is armed and there is a primed e-match on the other end. once the e-match blows the buzzer will stop sounding.

hope this helps

hi
thanks for the feedback
Just a few questions

What exactly do you mean by a CE/peer review?...I'm from Malaysia and I haven't come accross those terms before,...perhaps we use different terms here?
Whats an IEC connector? (sorry, but i'm not very familiar with all these terms)
The AC detector is a good idea...i'll look into that...shouldn't be too hard to add in :thumbs:
How do I replace the relay with a semicon? Totally no idea how to implement that...
If I were to put the buzzer series with the e-match, wouldnt it be silent until i pushed the ignition button and when I actually do that, it would sound like for a split second? (the duration that it takes the e-match to blow)

Sorry for all the questions
You see, I'm a mechanical student and all my electrical/electronic knowledge is what i've picked up over all these years that i've been a noosy parker...poking around other people's books and projects n stuff

Hope you can clarify these things for me

Thanks

I couldn't really give you any feedback myself but I'd say you've done a nice job! Looks very nice and compact, looks kinda like the design I'm going for when I build mine. Also them plans are lovely, nice and clear unlike most of I've seen.
Great first post!!

Regards,
Drew

Thanks
I used Microsoft Visio to draw the circuit
You might want to look into it
Its really versatile
It not only can draw electrical and electronic circuits, but also maps, hydraulic schematics, flow charts, progress charts, building plans, graphs, database representation, web diagrams,...i could go on and on
Honestly (imho), this is one of Microsoft's best softwares to date,...well; that and microsoft project...hehe