Not another university questionnaire!

[Adolf Hamster]

well, bit of an update.

so the lab work side of this hasn't born much fruit, not being an electrical engineer i've been struggling with getting a system that will put power into the coil to test the performance of it, and after much faffing around with health and safety, bug fixing etc we've not really got any decent data from the experiment. sadly i'm running low on time so i'm having to call time on the physical testing for the sake of actually getting the report written.

the good news is i've been re-running the simulations and i'm getting some promising looking data, turns out the whole permanent magnet idea doesn't really work and a simple steel core is much more effective:

that's a simulation showing the force on the piston as it passes through the coil, the different lines are different input powers from 0-10kw, this is for  ~35000 turn coil of 34swg wire

a 1j spring in a v2 box has a 20n preload and takes around 60n to compress so these results are looking promising, for reference my test coil is using 34swg wire and takes around 1kw of power with rectified mains voltage.

 

[Rogerborg]

The extension cord might be something of a trip hazard while out on the field.

 

[Adolf Hamster]

The extension cord might be something of a trip hazard while out on the field.

indeed, i had hoped to "cheat" my way around the electrical design side of this project, i started with bug zappers, then an industrial dc-dc converted (at a whopping 2500v ? ) but none of those could charge the capacitors i was using fast enough to overcome their natural discharge.

so then we moved to using rectified ac from a variac, which after the first incident involving the switch welding itself together took 2 weeks worth of making changes to risk assessments/mission statements before the lab guys finally let me back in.

i'm pretty confident the electrical side is possible, we might only have 11.1v but you can draw a lot of amps from a lipo so the power will be there to convert up to the higher voltages needed. it just needs a circuit that can do it, but that's beyond my abilities.