Little Big Project

[fasteddie600]

Noobs question here but does double up the FETs share the load between them?

That is my understanding of how it works, but I am no expert here!

Will stress test later hopefully see what happens! Hopefully I can keep the same underwear on this time, maybe taking off the Electric Wizard t-shirt will save me from any additional irony!

 

[fasteddie600]

Okay so looking good so far, Down onto 0.12 coil. 0.3V drop 3.5V at atty 100W and everything staying cool.

Will try and continue testing over the week but looks like 2 MOSFET's are better than 1!

Need to devise a way of reading multimeter through the thick fog I am creating!

 

[Loco]

Okay so looking good so far, Down onto 0.12 coil. 0.3V drop 3.5V at atty 100W and everything staying cool.

Will try and continue testing over the week but looks like 2 MOSFET's are better than 1!

Need to devise a way of reading multimeter through the thick fog I am creating!

Out of interest....does wiring mosfets in parallel effect what resistor you use?

Thanks in advance

 

[fasteddie600]

Out of interest....does wiring mosfets in parallel effect what resistor you use?

Thanks in advance

As far as I am aware the resistor doesn't need to be changed. However I am meeting tonight with an audio electronics engineer tonight and will ask the question to be sure. All working as it should at the moment though with the same resistor I fitted to start with.


Sent from somewhere inside a huge cloud!

 

[Chegs]

Out of interest....does wiring mosfets in parallel effect what resistor you use?

Thanks in advance

I've used a variety of different resistance resistors(reclaimed from an old PSU circuit board)and they all worked, so I would expect the same to be true with dual FET's.

Sent from my SM-T210 using Planet of the Vapes mobile app

 

[Hammy]

Also, would doubling up the Fets halve the resistance, as it does in fuses?

 

[fasteddie600]

Also, would doubling up the Fets halve the resistance, as it does in fuses?

I would expect so.

 

[fasteddie600]

So the Little Big Project looks to be near completion.

It is now sporting two 110A FETS and is currently running a 0.08 coil with 0.5V drop battery is almost fully charged and I am getting 3.65v on the 510 connector which means it is running a tasty 160W which is totally insane!
The FET's are getting warm but nothing exceptional 40-50 deg when using in short bursts-honestly I cant stand it powered for more than a quick press. Assuming this all works ok I am not going any lower.

Honestly I am not sure how I am going to use it, but, it is coming out to band practice tonight to check performance as a smoke machine and hopefully I don't end up in a ball of flames.

 

[fasteddie600]

Testing done, and I am not in the A&E burns unit so all is good!

Actually no problems at all, after a good evening hammering the little box with 0.08ohm coil no problems

Very impressed with this little box, 160W all evening and only got warm at most although the atty was stinking hot at times! This is now way out performing the my big box, about the most I can get out of 2xVTC5's is 120W with about 1v drop compared to the Lipos 0.5v on the same 0.08coil.
That's as far as I want to go testing I know I will start getting serious heat from the FET's if I push much more.

Liquid electrical tape has saved some hassle finishing everything off inside and it all looks reasonably tidy. Charger working spot on to 4.20-4.21 so box finished!

 

[Chegs]

I've just got my lipo balance charger today,so decided to rewire the battery configuration.I went from 4 x 1000 MaH cells in parallel for 4.2V to 2 x 1000 Mah parallel + 2 x 1000 MaH in series to get 8.4V.Tried a single coil of 0.5 MM wire @ 0.49 ohms,soon as I hit fire the wire lit up like a light filament & the traces of juice burst into flame.This coil snapped just blowing out the flame,so wound 10 wraps on 2.5 MM drill to get 0.88 ohms. There is zero voltage drop(least meter says none it can measure)and the Plume Veil single coil needs all airflow open fully or the vapour is just that little bit too warm.It's late so tomorrow I'll file the USB port wide enough for the JST socket & glue this in place(with a support behind it as the JST plug can be tight)& run it in parallel+series cell config for a few days. I'll also mess around with my stash of kanthal(flat/round)and see what 1mm x 0.1mm ribbon gives with 10 wraps as I'd like to get the PV dual coiled to around 0.5-6 ohms(this gives an 8.4V vape the same power approx as 0.14 @ 4.2V)but at half the current draw.Hopefully the 10 new lipo cells I've ordered will be here before I go Hawkshead so the morning we depart I'll be sat here soldering up an 8.4V 4400 MaH (ish) pack.