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ArcticMyst Security by Avery

small switches on drivers

Pman

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So, does anyone have any idea how much those small switches you see on drivers such as basically any pen out there can handle? I have never blown one regardless of output in my pen build although this time I'm building a special unit for someone that uses a 3W 445nm (whatever number it is). It's going to be momentary use and limited to short bursts anyways since it is a pen and there's not much more sinking than the copper front module piece that the diode is pressed into. I suppose I could take one apart and see if it is just a piece of wire or something that makes contact across 2 solder points on the board as that's what my head is telling me it is but if it isn't it would stink if the switch went after the build was done.

Just to be clear I'm talking about switches like these:
8fw1cZ.jpg
 
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GSS

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I obviously can't tell you how much it can take Amp wise but pulled apart a dead Fasttech module and it has what looks like a small copper foil disc that provides the snap or click that hits a center tab on the board when pushed all the while the edges of the disk are in contact with the other outside two solder points.:eek:
The disk is non magnetic.
 
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Those PCB surface mounted switches are only meant for input signals, not really for managing power. I don't think they can do more than an amp or maybe a couple amps for a few seconds. Last time I read the specs on one of those I think they're rated for no more than 300 mAh IIRC.
 

Pman

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Well I guess I'm going to just wire it up to the module and see what happens outside of the host.
 

94Z28

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I just burned one up recently.. it was a cheaper driver so the quality was bad but they will not handle much more than 1 amp. Mine failed at 1.8A within 20 seconds being powered by a lap supply also and no shorts.. I would expect these to be a hazard for any build. I eliminated the push button and the driver in question and designed a custom tail cap pushbutton to get arone it.. harvested the switch and button from a similar sized flashlight that burned out (Husky 2x AAA) which did well in holding the 1.8A load.

They're meant for low current signals as said above.. if you have the option then go for a tail cap switch that you've seen push a small amount of power.
 
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I'm using one of the black round type (top in pic) in my phaser build, with a Mits 500 diode pushed to about 1W. It seams to be doing fine, but I was concerned about it at first too. Of course I can't find it now, but I remember it being said that at even 1W it's pushing it with those small "tactical" switches.
 

Benm

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Indeed, the typical rating is something like 50 mA on them, certainly nothing in the order of a couple of amps. These ratings factor in a number of pushes they have to survive on average though, which could be 10.000 but also a million.

If you use them for high current they can fail quickly though, but open circuit or just contact-welded permanently connected.

They sort of survive the 'abuse' of being used in small green pointers with 0.5 to 1 watt pump diodes fairly well, but i doubt they'd last long if you tried ramming 5 amps through them. Also they have considerable contact resistance so they waste power even if it's not enough to destroy them quicky.
 





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