*help* MOSFET Box Mod Not Working Properly

[brandon83021]

Hello all, this is my first post so bear with me.

I can't sleep as I spent the last two days building an unregulated quad parallel box with an IRLB3034PbF MOSFET in it and an angel eye switch that I have wired to light up when the button is pressed, and I just won't work right.

Mod:
https://drive.google.com/open?id=0B05zlU7H3ekmS0ZyRlFadlpwYzQ
Mod on with button pressed:
https://drive.google.com/open?id=0B05zlU7H3ekmMXp0cHB4T3RRQk0

I wired the body negative to the body of the MOSFET, the sled negative to the Source pin and the sled positive to the gate pin through the switch.
Using a meter when I have power to the switch and the 510 open, I can press the button and I get a direct short before and after the MOSFET as read with a meter; that's what I want. Everything looks right and works well.

As soon as I connected my tfv8 with a .15 head, my button light stays on and when I fire nothing happens and I no longer have a short before and after the MOSFET which tells me it isn't opening up when pressing the button. The light also turns off when I fire which doesn't seem possible.

Atty on, light on, and button not pressed:
https://drive.google.com/open?id=0B05zlU7H3ekmSXlCR0NaMk5iTjQ
Atty on, button pressed, and light off:
https://drive.google.com/open?id=0B05zlU7H3ekmbmpkMk50TVNfS1k
Back of switch; left to right: negative for light taken from after MOSFET, positive(C1) going to battery, positive(NO1) going to gate and to switch positive for light, unused pin (NC1), positive pin for light
https://drive.google.com/open?id=0B05zlU7H3ekmWHMtbUtnd0ZGS00

I can not figure out why. So I switched to a higher build on another atty about .35 and it did fire but the light still stays on. What am I doing wrong? I hope Motley Mods didn't shaft me on the MOSFET.

Notes:
*I did check the resistor it is 15k across the gate and source.
*Light stays on when atty is in and no power is going to pin C1
*I am not using the drain pin as it directly shorts to the body, thus I used the body.
*All solder points are good.
*Yes I did use hose clamps on the positive wire to the sled and 510 pin(FDV v5 squonk) because soldering is a pain in the ass with 10 gauge wire.

Switch: wiring diagram is down below
https://www.superbrightleds.com/mor...e27Q2yzJdoC7qsw7YnJqsIqxT4TtlrEhoCiAcQAvD_BwE

MOSFET from Motley Mods w/ 15K resistor:
https://www.motleymods.com/collections/components/products/3034-mosfet-15k-resistor-heat-shrink

IRLB3034PbF Datasheet:
https://www.elektronik-kompendium.de/public/schaerer/FILES/irlb3034pbf.pdf

Please ask any questions
Brandon

 

[brandon83021]

Update: when I measure resistance between the positive and negative of the 510 with an atty in it reads the atty resistance. When I fire it the resistance shoots through the roof

 

[The Cromwell]

disconnect the LED.
You need a double pole switch to run the LED off the other set of contacts.

 

[brandon83021]

disconnect the LED.
You need a double pole switch to run the LED off the other set of contacts.

How exactly would I need to wire that led to work when firing? And is that causing me to have the high resistance somehow? Thanks for the reply I will go test now

 

[The Cromwell]

You cannot do it with that switch.
it is spdt you need a double pole switch.

And NEVER us that switch or one like it it will latch on permanently.
A darned dangerous thing to put in a mod.

 

[brandon83021]

Hmm I don't underatand anything about an spdt but I will do some research! Thanks for the advice! I actually liked that it was a soft momentary and hard on/off. Its almost 3/16inch required to keep it on so you need to try hard, but I understand. May just switch it out here.
Thanks again. Will reply when done testing

 

[The Cromwell]

if you want an LED you will need a DPST momentary contact switch.
One set of contacts will be for the Mosfet and the other for the LED.

 

[brandon83021]

So I disconnected the led and still no cigar, I can wire a normal single throw switch?

 

[brandon83021]

One other thing, I notice that I was getting a voltage drop of about .2 volts and slowly climbing and I am still getting that with the led disconnected

 

[brandon83021]

So update, I replaced the switch and when firing I get extremely high resistance and voltage drop and nothing happens

 

[The Cromwell]

Extremely high resistance where? voltage drop where?

You cannot measure resistance with a DMM while voltage is on a circuit.

If your circuit is wired like the diagrams on the site where you got the Mosfet and it does not work you blew the mosfet or have a bad connection.

IF it is wired like the circuits on the web site.

 

[brandon83021]

It is wired that way which is weird... And that is true, I should know better, the coil will for sure impede current flow under load. I guess next step is try another mosfet...

 

[Iliketurtles]

You should post your mod wiring diagram - then people can see what is likely wrong or maybe you will see what you did wrong yourself. No diagram = not much chance of anyone guessing what you missed out / wired wrongly.

 

[brandon83021]

I'll try to make one up tomorrow but I believe I recieved a bad mosfet.

Only soldered 20 gauge wire to the gate lead and somehow it seems to be damaged. Switch doesnt seem to have been an issue at all as I replaced with a spst switch, just a simple clicky one and nothing happens when I fire except a large voltage drop and the mosfet gets hot.

Diagram is as motley mods and many other forums show. Works properly when no rda is in or when the rda is above .5ohms resistance.
Will replace mosfet when they arrive and will try to make up an old and a new diagram!
Thanks for the advice/help so far

 

[brandon83021]

Okay, so new mosfets haven't arrived yet, but here are the old and new diagrams I said I'd post. Although the light was not working properly on the angel eye I believe the switch was still doing what it needed to do for the rest of the circuit and so the mosfet was bad. We'll find out! Let me know what you think

Diagram with angel eye:


Diagram with simple switch:

 

[Iliketurtles]

So going by the diagram, without the -ve connection provided when the gate is high nothing can come on. But you have things on when the button is not pressed....so you have a -ve connection from somewhere. Usually I would suspect a failed MOSFET or that I melted part of the switch, either way I would take it apart if it was mine and test each component out of circuit....as there aren't many components...and theres nothing better to do.

You have too many big metal lumpy things in there for me, and a bit of wood, and a bit of cardboard. I see the possibility of a fire in your future. But we've all done some sketchy shit I guess

 

[brandon83021]

Thanks for the reply!

If I catch a piece of wood on fire underneath batteries I am seriously doing something way out of the scope of vaping XD especially behind a voltmeter. Either way it wasn't done being built so I will update at that time.

Anyway, could you clarify "-ve"? I just don't know what you mean, my bad.

Otherwise, all parts are brand new and were checked before installing actually, and for good measure I have checked again. I did want to make sure connections could be permanent, one time. Definitely not my first box haha.

So as this is a learning curve, do I need to connect the drain to the ground? It seemed as though the body was connected to the drain so I figured using the body is a better contact. Let me guess the drain needs to connect to the body/ground to work...

 

[Iliketurtles]

-ve is battery negative. The mod body can be used as a wire like you have done, I would say it is a pretty good wire. Drain is -ve only when the gate is biased otherwise the mod will fire all the time. The mosfet is being used as a switch as it can carry much more current than the actual 'switch'. So according to your diagrams the led and the atomiser cannot be ON if the mosfet is not ON (putting the -ve through to the mod body) but in your picture they are. So either 1- you have a stray connection 2- mosfet is broken 3- switch is broken, or 4- its not wired like the diagram.

 

[brandon83021]

Hey everyone! Mosfets came in today

I did was some more research on engineering forums etc and I found that what I did in using the body and not the drain pin was in fact completely possible.

The mosfets finally came in so I gave it a try and I hooked it up EXACTLY how I did before using the body instead of the drain pin.

Low and behold, it works like a dream!

I appreciate all the replies and in the end it was only a bad mosfet. The spdt switch would have worked just fine with a working mosfet that wasn't defective and it was properly hooked up as I had tested it before hand.

One more note, I am never ever ordering from MotleyMods again as I asked for a refund because it was defective and I was basically told too bad and to buy another one so I can "leave bad review for my mistake". Not to mention it was way overpriced. Unbelievably rude and selfish.

Hopefully this thread will help someone else

 

[The Cromwell]

Hey everyone! Mosfets came in today

I did was some more research on engineering forums etc and I found that what I did in using the body and not the drain pin was in fact completely possible.

The mosfets finally came in so I gave it a try and I hooked it up EXACTLY how I did before using the body instead of the drain pin.

Low and behold, it works like a dream!

I appreciate all the replies and in the end it was only a bad mosfet. The spdt switch would have worked just fine with a working mosfet that wasn't defective and it was properly hooked up as I had tested it before hand.

One more note, I am never ever ordering from MotleyMods again as I asked for a refund because it was defective and I was basically told too bad and to buy another one so I can "leave bad review for my mistake". Not to mention it was way overpriced. Unbelievably rude and selfish.

Hopefully this thread will help someone else

I still would NEVER use a switch that could be locked in the on position.
If something can happen it will at some point.

 

[brandon83021]

I totally agree with you Cromwell, I guess I liked the light too much.
There are even switches that light and are the correct switch, just a stupid move on my part!

 

[Iliketurtles]

Cool, glad its working now.

 

[The Cromwell]

I totally agree with you Cromwell, I guess I liked the light too much.
There are even switches that light and are the correct switch, just a stupid move on my part!

It was a cool looking switch though.

 

[brandon83021]

Some pics:

Mod with 30mm temple on it(prima chuff cap soon to come):
https://drive.google.com/file/d/0B05zlU7H3ekmNi1tX1ZRNEtacTA/view?usp=drivesdk
With Prima Cyclon3 Cap:https://drive.google.com/open?id=0B05zlU7H3ekmVi1Mc1VFbkRjcVk
https://drive.google.com/open?id=0B05zlU7H3ekmVi1Mc1VFbkRjcVk

Basically finished guts:
https://drive.google.com/file/d/0B05zlU7H3ekmZjFBelFYZkh4aUU/view?usp=drivesdk

 

[The_BIG_Red89]

Hey everyone! Mosfets came in today

I did was some more research on engineering forums etc and I found that what I did in using the body and not the drain pin was in fact completely possible.

The mosfets finally came in so I gave it a try and I hooked it up EXACTLY how I did before using the body instead of the drain pin.

Low and behold, it works like a dream!

I appreciate all the replies and in the end it was only a bad mosfet. The spdt switch would have worked just fine with a working mosfet that wasn't defective and it was properly hooked up as I had tested it before hand.

One more note, I am never ever ordering from MotleyMods again as I asked for a refund because it was defective and I was basically told too bad and to buy another one so I can "leave bad review for my mistake". Not to mention it was way overpriced. Unbelievably rude and selfish.

Hopefully this thread will help someone else

That's really surprising to hear. I just got a g box kit from them and I stupidly melted my insulator by not disassembling before soldering. I had used a varitube v2 before this one and assumed they were all like the varitube. So I emailed them explaining how I messed it up and asked if it was possible to purchase just an insulator or if they had upgraded insulators. He responded with a tracking number and said not to worry about it. Maybe someone there was having a really bad day or something.

 

[brandon83021]

Oh I have melted insulators just evening out hot spots on my dual 16awg nichrome 80 build... But I am using a fat daddy v4 I believe with the squonk pin and the ceramic baked insulator which was all just easier to work with. I managed to crack the damn thing but it was small enough the I was able to repair the little void with gorilla glue as it only cracked maybe a third of the insulator off on the side. By far the most abuse ive seen a 510 take.

Yeah I don't know if there is a team of just the guy who is in all the videos on their site. Either way im done and gone with them! Glad you had a good experience though!