Voltage reference for coilgun

[jjjasesino]

Hello, I´m lesrning something about coilguns ( in fact i did one but with a camera flash......) and now i want an upgrade, i have everything but the charger and this seems very good material, i also have some comparators as the lm393n or the lm311p

i did some succesfull experiments doing something turn off when a potentiometer lets the voltage rise to the 12v of reference from the battery, but in this circuit, my goal is to stop charging at arround 380v but i dont have an external supply of 380v to compare with, i think i should use a voltage divider but not sure how it works or where to place, also it would be nice a potentiometer in order to change the maximum voltage of the comparator, some help please?

 

[DerStrom8]

Hello jjjasesino ,

I have moved this post to its own thread so that you don't hijack someone else's thread.

Being a coilgun, this may or may not be allowed, as we do not usually host projects regarding weaponry. Assuming you keep it on a very small scale, however, it may be acceptable. This will have to be discussed among the rest of the moderators to determine whether or not it will be allowed. I hope you understand.

Regards,
Matt

 

[JimB]

There are umpteen threads in the past discussing coil guns, so I dont see that the topic should be verboten now.

JimB

 

[DerStrom8]

I was thinking the same thing Jim. So jjjasesino , you should be ok for now, just as long as you don't plan on making it too large

 

[alec_t]

Apart from the obvious danger of the projectiles, are you aware that a cap charged to 380V can be LETHAL?.

 

[nuclearrambo]

I think you can make a voltage divider across the output capacitor. Have a very large resistor and a small resistor in series. Measure voltage across the smaller one (make sure that the voltage drop across it is quite small. You can do it by adjusting the ratio of the large res and the small res).
If you do it right, the voltage across the small one can be made to be under 10-15 V. This should be manageable.