Making On/Off LED Switch?

[AllHokage]

Hello everyone,

 

So I'm thinking about modding my 'Bitfenix alchemy 2.0 led strips', so they can turn on/off with a click of a button. As I'm leaving my PC on 24/7 and don't want the LED's on all the time.

 

Would I simply just cut the molex extension cable 'ground cable', solder it to a switch and then shrink wrap it (so it wont short) and place the switch where I want it?

 

If someone could let me know if this will work it would mean alot, also would this be safe to use?

 

[rhyseyness]

That will work fine.

Black wires are ground though, not yellow

Both the black wires onto each terminal of the switch and you're golden

 

Molex connector->2 ground wires->switch->2 ground wires->molex connector

 

All in series the same as your diagram, just using the black wires instead of the yellow one.

Hope this helps

[Kobrastachka]

yes (if the leds are 12v and not 5v)

[AllHokage]

6 minutes ago, rhyseyness said:

That will work fine.

Black wires are ground though, not yellow

Both the black wires onto each terminal of the switch and you're golden

 

Molex connector->2 ground wires->switch->2 ground wires->molex connector

 

All in series the same as your diagram, just using the black wires instead of the yellow one.

Hope this helps

Ok so something more like this. Also is this safe, as this is my 1st time soldering and don't want the computer in flames or it to cause a fire while I'm out

 

[alexboz]

As far as safety, it can't hurt to test the resistance between the different wires with a multimeter to be sure nothing is touching/shorting.

[rhyseyness]

4 minutes ago, AllHokage said:

Ok so something more like this. Also is this safe, as this is my 1st time soldering and don't want the computer in flames or it to cause a fire while I'm out

 

Yep just like that

Perfectly safe as long as you make sure the exposed metal on the switch/wires is completely insulated (shrink wrap).

Also make sure your switch is rated for enough current.

Can't remember what the Molex spec is off the top of my head, but shouldn't be more than 5 amps

[AllHokage]

2 minutes ago, rhyseyness said:

Yep just like that

Perfectly safe as long as you make sure the exposed metal on the switch/wires is completely insulated (shrink wrap).

Also make sure your switch is rated for enough current.

Can't remember what the Molex spec is off the top of my head, but shouldn't be more than 5 amps

Ok thanks for the help, I'll just go for something rated much higher so I don't get any issues

[mariushm]

The switch only has to be rated for more current than what the strip uses, not the maximum the cable can carry.

Theoretically, an AWG18 cable that's commonly used in power supplies can carry up to 10-15A on the short distances that are between power supply and devices (but the 5A is a safety limit imposed by the molex connector pins and the way they interconnect)

 

Also note that switches are rated for a current that's usually low for DC. Doesn't mean the switch can't handle a bit more current than that, it just means that the switch won't last as much as a properly rated (bigger) switch.

 

Basically, when the metal contacts inside get close to one another as you close the switch, and also when you press the switch to separate the contacts, with high currents it's possible to have a sort of electric arch or sparks between the two contacts inside the switch for a super brief moment until the contacts are fully separated or fully touching.

 

With turn on/off cycles those sparks inside the connector can degrade the surface of the contacts and at some point the switch won't work properly or in some cases the resistance between the contacts goes up and the current going through the switch overheats the metal contacts and then the plastic of the switch also melts and so on...

 

The values listed in the datasheet for a switch are something like "estimated or measured for 5000-1000 cycles of operation" so if you're only going to turn on or off those strips a few times a day, you don't have to worry about it, you can just replace the switch once every year or every couple of years.