sub ohm switch on diy mod

[mcleftnut]

Hey. I'm new to modding and was wondering what the amp rating on a switch should be if I wanted to sub ohm. I am planning to build some altoids mods.
I know that on a 10 amp battery you should only go to .42 ohms. But if I had a switch that was like 3 amps would a .8 ohm build kill the switch because 4.2(V)*0.8(ohms)=5.25(Amps)???
Or would I have to calculate the voltage drop. Sorry if I am being vauge on the type of mod I am planning to build because I have not fully decided yet.
Thanks for the help I hope my question made sense.

 

[87slosohc]

The switch will fail prematurely, could use a mosfet that can handle the load though or make a mechanical switch.

 

[bgibs1]

Go to madvapes hes got some cheap 5amp switches... they've been fine on my Altoids box firing it at .5

 

[david4500]

16 amp http://www.digikey.com/product-detail/en/PA414C1100/PA414C1100-ND/3777968

 

[tabs808]

I have been using these 2a vandal switches on my mech dual 18 and 26 boxes and have never ran into any issues.
Had builds as low as 0.06ohms yestes through these switches.
http://www.digikey.com/product-detail/en/PV2F640SS/EG4705-ND/2116184

 

[tabs808]

They are rated 2a at 48v dc. So I figure the lower the voltage, the higher the amp rating right?

 

[Quigsworth]

That only works in wattage calculations...if a switch is rated at 2A that's it, regardless of voltage...typically voltage is given in a switch spec as a testament to it's dielectric strength (it's designed contact gap voltage)

 

[tabs808]

Ohhh makes sense. Well I haven't ran into any problems yet lol

 

[zillaC]

Would a 'carlingswitch' that says 12a 125vac 1/2hp 8a 250vac 1/2 hp work for sub ohm? Oh and its a rocker switch, thanks!

 

[WharfRat1976]

The risk of switch failure is massive. It may work great for a month or 3 or longer...if it dies when open then you have a problem and all it takes is one....

 

[rhelton]

If your taking the time to build yourself a nice mod why wont you spend 2.50 extra and put in a pfet.

Seriously what planet am I on.

I dont know much, but I do understand amps and there are a lot more smarter people around here who have shown me, and other the safe way of doing this. I know its cheaper to cheat, but only by 2 or 3 bucks.

 

[Quigsworth]

The risk of switch failure is massive. It may work great for a month or 3 or longer...if it dies when open then you have a problem and all it takes is one....

Agreed, but peeps are gonna do/think what they're gonna do/think, it's their face/hands <<shrug>>...thing is, switches do much more than simply make an electrical connection, hell, that's the easy, you can do that with a paperclip and a rubber band...the essential part is the switch being able to effectively break the connection under load. We deal exclusively in DC current (up to the 30A in a fault condition), remember, just like fuses, the current through our coils, which is dictated by our coil resistance is only part of the equation, we also have to consider what the battery will put out...I'm not saying you need a 30A switch, just be mindful that these stopped being toys long ago.

When you push a switch beyond it's rated current disruption capacity you're playing Russian roulette...note I said "disruption"...if the contact points are too light, excessive heat builds, if the "break" spring is too weak, the arch cause by a collapsing magnetic field (induction) super heats the flimsy contact material and may possibly weld the switch in the closed position (not good)...at the very least, every cycle of over driven contacts pits the surfaces, which creates excessive arching, which pits them more, and so on...it's a good thing we can't see inside that 2A switch that works just fine on our .5 dual coils, if you could you'd be scared.

...then again, maybe the laws of physics don't apply to them

 

[Norrin]

If your taking the time to build yourself a nice mod why wont you spend 2.50 extra and put in a pfet.

Seriously what planet am I on.

I dont know much, but I do understand amps and there are a lot more smarter people around here who have shown me, and other the safe way of doing this. I know its cheaper to cheat, but only by 2 or 3 bucks.

Or and this depends on the mod, space, form factor....blah blah, make your own mechanical switch. So there are 2 fairly cheap safe ways to do it, but many still just shove a sub standard switch in and pray

 

[rhelton]

I know they do, I see at least 5 to 10 posts every day between here and reddit about the same thing.

Mods do catch on fire.

 

[granolaboy]

I have been using these 2a vandal switches on my mech dual 18 and 26 boxes and have never ran into any issues.
Had builds as low as 0.06ohms yestes through these switches.
PV2F640SS E-Switch | EG4705-ND | DigiKey

I'm using this in my parallel 18650 box mod I made. They're rated 2A at 48V, so pushing 24A at 4V seems reasonable. My builds are around 0.25Ω and the switch doesn't get hot at all.

 

[Quigsworth]

I'm using this in my parallel 18650 box mod I made. They're rated 2A at 48V, so pushing 24A at 4V seems reasonable. My builds are around 0.25Ω and the switch doesn't get hot at all.

...ya know...peeps come on ECF looking for help and sound advice...when I see posts like this with your complete disregard for your safety and others I really hope the mods would step in and stop this kind of crap.

Please, do one of 2 things, learn some basic ohms law or 2, have some respect for your fellow vapers and just stop posting.

 

[classwife]

Please make sure you learn all you can and practice safety - we don't want to hear of failures on National News thank you !


Hijacked OP's thread from July...closing












too bad more people don't report these things instead of just griping about it