LED Strip Question

[maidofsteel]

Hi all,

 

I have an Phantek Enthoo Pro Full Tower case and I'm thinking of spiffing it up with LED strips. I don't need anything fancy like a controller; I just want it to light up when I turn on my PC. I'm trying to save some money since the rest of the parts already cost me a lot. I found this thing on eBay:

 

http://www.ebay.ca/itm/25-50CM-3528-5050-5630-LED-for-PC-Computer-DIY-Flexible-Case-Strip-Light-DC-12V-/141709221918?var=&hash=item20fe87201e:m:mAGyjuc328w0nWzGVWrrOLQ

 

It's 50cm 5050 Blue LED strip with a molex pin for around $2.50 CAD. My question are as follows:

 

1. Will a cheap LED from Asia have a chance of burning down my PC? (Might sound stupid but it's a serious question; I know very little about LEDs except they look cool)

2. Does anyone with an Phantek Enthoo Pro Full Tower case know much many strips would work well? I'm thinking just one strip on the top will do, but the case is pretty big so maybe two on the sides instead would be better?

3. The screen on my case is pretty clear; will 5050 be too bright for it? Would a 3528 LED work better if there's no tint on the screen?

 

Thanks!

[mariushm]

It's almost impossible to damage computer with the led strips.  LEDs if they die, they usually die "open", meaning there's no connection between + and - of each led, so the power supply won't see that as a short circuit.

If by some miracle a led fails short (closed), the wires going from the led to the computer are so thin that they will break way before the power supply will even notice the LED died.

If somehow the wire doesn't break/burn up, the power supply will detect that short circuit (maybe over 70% of power supplies have this feature) and will turn themselves off. If they don't, you'd smell something smoking (the insulation on the wires between the power supply and the strip most of the time) because the wires heat up and you'll turn off the computer and disconnect the strip.

 

Individual leds use around 20mA (0.02A ) and the led strips usually make groups of 3 leds to power those 3 leds from 12v  (each led needs only about 3 .. 3.2v to light up, so 3 leds in series is about 10v, and that makes it OK to power the set of 3 leds from 12v, with the help of a current limiting resistor)

 

can't answer question number 2

 

as for 3 ... the size of leds usually doesn't tell you anything about how bright they are.. it depends on the lens that sits on top of the led, how narrow the angle is on the lens .. the led can be made like a laser pointer lightning only a narrow spot and therefore appear very bright , or the lens could have wide angle in which case the led may appear less bright.

The amount of current allowed to go in the led also tells you if the led will be brighter or less bright ... the majority of the led strips will configure each led to get about 10-20mA ... you could desolder the led and use a bigger value resistor to reduce the amount of current going in the led (so it would be less bright)

 

there's also led strips with CLEAR leds which will be brighter , and leds with matte / opaque lens ... the later ones will spread the light more nicely and uniformly but will be less bright.

 

[maidofsteel]

15 minutes ago, mariushm said:

It's almost impossible to damage computer with the led strips.  LEDs if they die, they usually die "open", meaning there's no connection between + and - of each led, so the power supply won't see that as a short circuit.

If by some miracle a led fails short (closed), the wires going from the led to the computer are so thin that they will break way before the power supply will even notice the LED died.

If somehow the wire doesn't break/burn up, the power supply will detect that short circuit (maybe over 70% of power supplies have this feature) and will turn themselves off. If they don't, you'd smell something smoking (the insulation on the wires between the power supply and the strip most of the time) because the wires heat up and you'll turn off the computer and disconnect the strip.

 

Individual leds use around 20mA (0.02A ) and the led strips usually make groups of 3 leds to power those 3 leds from 12v  (each led needs only about 3 .. 3.2v to light up, so 3 leds in series is about 10v, and that makes it OK to power the set of 3 leds from 12v, with the help of a current limiting resistor)

 

can't answer question number 2

 

as for 3 ... the size of leds usually doesn't tell you anything about how bright they are.. it depends on the lens that sits on top of the led, how narrow the angle is on the lens .. the led can be made like a laser pointer lightning only a narrow spot and therefore appear very bright , or the lens could have wide angle in which case the led may appear less bright.

The amount of current allowed to go in the led also tells you if the led will be brighter or less bright ... the majority of the led strips will configure each led to get about 10-20mA ... you could desolder the led and use a bigger value resistor to reduce the amount of current going in the led (so it would be less bright)

 

there's also led strips with CLEAR leds which will be brighter , and leds with matte / opaque lens ... the later ones will spread the light more nicely and uniformly but will be less bright.

 

Very informative, thanks a lot!