simplification of the switch for those new to modding...

[MadmanMacguyver]

I had some issues for a while looking for then trusting my judgement on switches and their ability to handle our uses...

Here is the perfect answer...stop worrying about volts AND amps (outside the range we use)and simply use one of the ohms law conversions( I use the PV tuning section in Breaktru's E-juice me up juice calculator) figure out the Watts and use that to decide if your switch will work...this is the easier way as the majority of switches are not made for the range we work(in fact most are rated for a much higher watt rating)15-20 watts is more than enough for most mods unless you are building a vape CANNON...lol

also pay attention to the durability of the switch you are choosing and materials it is made of...

A person new to soldering migh want to pick a switch w screw lock terminals as too much heat will damage the connectors resulting in the loss of a 2-14 dollar switch...not good and very discouraging to someone just getting into this new world...
also the number of presses the switch will handle is important...

I hope this helps a few people...

PS is some mod wishes to edit and make this post more legible go ahead...(I'm having too many of my own issues lately to spend much time on this but I do know if this or similar had been a sticky it would have saved me many headaches)

 

[breaktru]

Very good MMM. The wattage thing would work great on DC to DC rating conversion or AC to AC rating conversion but would not be accurate for a AC to DC rating conversion.
I don't believe there is a formula to convert AC amperage to DC amperage but as an example take a C&K pushbutton switch,
Ratings are 3a @ 120VAC / 3a @ 28VDC. Amperage rating increases when voltage decreases. 6a @ 14VDC, 12a @ 7VDC. OR... 1.5a @ 240VAC

Update Note: I'm not saying there is a difference of amperage for an AC or DC circuit, basically amperage calculations are the same.
What I'm trying to say here is DC arcing plays a role in the rating difference of a DC rated switch compared to an AC rated switch.

 

[slimest]

Agree, in common this is the best idea - to count wattage of a switch. Simple and reliable enough for novices.
Good advice.

 

[Rocketman]

How does the switch know what wattage you are vaping? The switch sees "open circuit voltage" when open and "contact voltage drop" when closed. High voltage rating applies to insulation and contact profile to reduce arcing. Some switch designs MAY be able to handle a higher current at low DC voltage but the current rating of a switch is not related to the watts in the circuit. A switch rated at 1 amp @ 24 volts would be rated at just how many amps at 3.7 volts? How about contacts in a small 5 volt relay rated to switch 120 volts @ 0.5 amps? The insulation is good enough to switch 120 volts AC, and heavy enough to switch 0.5 amps. It may be able to switch a little higher current at lower, non arcing DC voltages. Most switch ratings are limited by internal dissipation.

The wattage a switch "sees" are the watts dissipated in the switch itself by the current flowing through the closed contacts and the resistance of those contacts.

 

[slimest]

Rocketman, of course it's just for those who begins. If you want to make something really reliable, you have to consider another factors, say, if the switch or relay designed to work with AC or DC, cross-section of contacts and wires etc. But I think for simple mechanical e-cig mods this assumption - a switch can work if its allowable power fits - is enough, should work.
In my own service practice I sometimes followed the same rule: if you want to make burnt contacts to work, replace them with something close in parameters even it does not fit exactly

 

[MadmanMacguyver]

thats just a general rule I came up with not cannon...it works in most cases...but I dont cross AC rated switches w DC rated switches...thats just bad practice...as for stuff being rated exactly or even close to what we need...not gonna happen in most cases...98% of the components I find online are just not made to function in the parameters we need...and if say I'm using a 120 watt switch to do the job of a 15-20 watt switch it serves the purpose perfectly if it is durable enough mechanically...

I have mods that have gone over a year on switches w a voltage rating of 50 or so volts DC...besides as of the last 3 mo I have gone to replaceable switches to head off that problem...