Coilgun Help

[Kiptox]

I have recently been making a coilgun in my spare time and have reached a snag. I have no idea where I would put a voltmeter so I would know when to send 350 volts through the coil. Any ideas where?
(THIS IS JUST FOR A SCIENCE PROJECT. I WILL NOT BE USING IT TO CAUSE HARM TO OTHERS)
(Schematics below)

 

[#12]

You would measure the high voltage across the high voltage capacitor, but if you don't know enough about electricity to know that, I don't think you should be playing with stuff that can kill you.

 

[4pyros]

Your relay is not going to last long!

 

[RMMM]

Really friend, if you dont know by second nature how and where to use your meter on a circuit, you can end up blowing up your meter, or blowing your fingers off.

And not "nice clean" cuts that can be re-attached.. but "exploded-ripped and burnt" cuts that go in the trash.

Make sure your meter is set properly. Make sure the probes are in the correct areas on the meter. Do the math to be sure the voltage on the caps do not exceed the rating of your meter.

If your meter has a max of 300v, and you are using a flash circuit to charge the caps, they can EASILY get to 400+ volts.

No good.

Do not work on this alone. One "oops" can lead to you being on the floor with your heart stopped. With no help, you are going to stay dead.

Im sure your parents would rather pay for a proper meter rather than paying for a funeral.

Dont skimp on components. If it says you need a 450v cap, dont use a 16v cap. They will explode sending aluminum shrapnel everywhere.

If you hear or smell something odd, remove power. Do not lean over your circuit looking for the problem. The caps can and will explode. Especially if you accidentally connect one or more backwards.

They will blind you, burn you, cut you, etc..

If you have not did the basics of "lighting an led" and reading about ohms law, and using a meter, Then you should shelve this project until you KNOW EXACTLY where and HOW to meter such a dangerous project.

 

[4pyros]

Ya stay away from high voltage!

 

[cowana]

Furthermore, expect the realy to weld shut very quickly.

That will permantly energise the coil (for say 0.1s, until the caps have discharged). This will just pull the projectile into the centre of the coil, sending it nowhere.

Wait before you fully understand all of the maths before you do this project.