4 replies to this topic

[superspud]

hi, i use electronic ignition in everything i do, and i am getting fed up of having misfires becaus the croc clips arnt on right, so i am going to put a continuety tester in the firing unit. only problem being, it uses NiChrome and that burns at hardly any current, so my diliema is, how do i put enought current through to power an LED or sutable amplifier without firing my device in the process....

any idears|

my first throught was to just get a POT and turn th resistance up until the wire started to burn then turn it down abit and get a very low voltage LED....

[ChesterPFX]

Are you sure the misfire is down to the croc clips? It would appear to me, not knowing how your system is set up, that if the clips are physically attached then the circuit should be complete. Have you tried wrapping the Ni Chrome around the clip a few winds after you've clipped it in? Is there something coating either the jaws of the croc clips or the Ni Chrome which is reducing conductivity? Are you using enough juice to actually get the Ni Chrome hot?

[superspud]

the way i do it, is get some solid coper core, and strip half a cm at the end and wind the Nichrome round, then wind
it round the other bare copper wire, with a 5mm gap. i then put that inside the device and croc clip the wire to the detonation device. it works very well, but if there are any misfires its becaus there is a loose conection between the croc and the wire...

[Arthur Brown]

You use the d*** word, which will bring you the the notice of the board controllers, please be careful.

The requirement for precision and accuracy in electric igniters is only apparent when a situation like this occurs. One brand of commercial igniter is 1.4 ohms, 20mA sure no fire (for testing), and 500ma all sure fire. The range between 20 ma and 500 ma is a range of uncertain performance.

If you really need to make your own then you must make a design, then make a large batch of prototypes and test them for reliability and properties. only when your design and method are reliable should you fuse a device with one. Walking up to a misfired device is a risk but leaving one un-cleared is even more hazardous.

Start by using a LCD low ohm meter to measure the resistance of a batch of igniters without any compound .

[adamw]

Yes... I noticed!!