DIY LED light

[zonerx]

Did anyone drive their DIY LEDs with those 12V power adaptors? (those look like laptop power supply)

I got 5x10w leds chips, in theory a 12V 5A power adaptor should be enough to power all 5 10w leds rite?

Anyone can advice?

thanks

[sunny03]

Led one of the important point is constant current.

[bezz]

the adaptors are constant voltage. Led needs constant current like Sunny mentioned. you can drive them with the adaptor, but they will blow out very fast.

[zonerx]

Thanks, so is it necessary to add additional components? Resistor or regulator?

Will it blow out if the current supplied are lower than the rated current required by the LEDs?

The LED rated 1.05 amp each... When factor in the resistance each led should be getting less than 1amp, rite?

[sherman]

Better to get a constant current driver.

If not your LED 's life will be shorten tremenously.

Normal LED can last at least 50,000 hours before it start to dim down

[sunny03]

+ 1 it is better for you to get a led driver ... save you the trouble of changing led and adaptor. ..

Get meanwell drive from overseas cheaper... those china driver sold in slt usually dont last

[Firestarter]

Did anyone drive their DIY LEDs with those 12V power adaptors? (those look like laptop power supply)

I got 5x10w leds chips, in theory a 12V 5A power adaptor should be enough to power all 5 10w leds rite?

Anyone can advice?

thanks

Yes it can be done. May I know what is the mA for each 10W bulb?

[zonerx]

thanks for all the feedback guys

[zonerx]

Yes it can be done. May I know what is the mA for each 10W bulb?

each is rated 1050mA

[qingwen]

better to get a driver unless we've got someone pro here who has done it before

[zonerx]

anyway I'll give it a try and see how long it will last, already done with salvaged parts and so far so good

[qingwen]

anyway I'll give it a try and see how long it will last, already done with salvaged parts and so far so good

good luck! do post some pictures and updates!

[zonerx]

haven't got time to look for 10w resistors for each led...

[zonerx]

can drive direct from power adaptor but will kill the adapter very fast coz of overheat.

[gp2700]

bro can elaborate more details ?

A few months back I was toying with some 10w LEDs (same spec as yours, 1050mA). I tested it with a 12Vdc5A PSU and to my surprise, it drew close to 3A instead of the 1.05A.

This means that if you are using a 12Vdc1A PSU to power each LED, you may be overloading the PSU hence the overheating.

Now, if you connect the LEDs in parallel and power it up using a 12Vdc5A PSU, you might be overloading the PSU as well. Kirchhoff's Current Law comes to play here and you'll end up with a huge current draw at the main circuit.

But if you use a constant current source, the current supplied is designed to be constant and will not give out more amperes even if the device demands more. Either way can work but alot depends on the circuit design.

[zonerx]

bro can elaborate more details ?

A few months back I was toying with some 10w LEDs (same spec as yours, 1050mA). I tested it with a 12Vdc5A PSU and to my surprise, it drew close to 3A instead of the 1.05A.

This means that if you are using a 12Vdc1A PSU to power each LED, you may be overloading the PSU hence the overheating.

Now, if you connect the LEDs in parallel and power it up using a 12Vdc5A PSU, you might be overloading the PSU as well. Kirchhoff's Current Law comes to play here and you'll end up with a huge current draw at the main circuit.

But if you use a constant current source, the current supplied is designed to be constant and will not give out more amperes even if the device demands more. Either way can work but alot depends on the circuit design.

I'm using 12v dc 5a psu and leds in parallel connection

[zonerx]

so what is the best way for such setup? direct driver?

[mjck]

Leds need constant current power supply in iter for you to limit the current fed to the semiconductors. Out laptop power supply are constant voltage ...not current.

[zonerx]

I see, so adding a 10W resistor is one way to do it too i guess, thats what I saw how the leds shop at slt conect to their 10w display leds.

[Jameshong]

I would strongly urge you to go for LED driver, if you are seriously want to prolong your LEDs which few reefers here have already adviced you before.

Btw, parallel and series connection are both fine. For parallel connection, simple current protection circuit would be adviceable to put in place in case of all LED blow off due to one LED short circuit. Whereas series is more simple and safer so it is the way to go for beginner even for expert !

[gp2700]

For parallel circuits, try to use a current mirror setup to balance the current from the PSU. More complicated to setup but hey, you want the LEDs to last right ? *grin*

I'm currently working on a 16 x 10W LED project and am experimenting with a new idea of have 16 x 10W LED drivers to power them up. The first 4 should be up by end Feb cos I'm still waiting for the shipment to arrive.

Series circuits are easier to setup as mentioned by bro Jameshong, the only problem is the PSU. i.e 12V for 1 x LED, 24V for 2 x LED .... 48V for 4 x LED The more LEDs you connect in series, the higher the voltage. Unfortunately, the pricing increases with the voltage as well.

[oceanviper]

I see, so adding a 10W resistor is one way to do it too i guess, thats what I saw how the leds shop at slt conect to their 10w display leds.

10W resistor is not cheap and is going to be very hot!!!!!!!

[julius]

each is rated 1050mA

Have you tried looking this supply "9.52V 5.25A". You need not to purchase any resistor

[zonerx]

For parallel circuits, try to use a current mirror setup to balance the current from the PSU. More complicated to setup but hey, you want the LEDs to last right ? *grin*

I'm currently working on a 16 x 10W LED project and am experimenting with a new idea of have 16 x 10W LED drivers to power them up. The first 4 should be up by end Feb cos I'm still waiting for the shipment to arrive.

Series circuits are easier to setup as mentioned by bro Jameshong, the only problem is the PSU. i.e 12V for 1 x LED, 24V for 2 x LED .... 48V for 4 x LED The more LEDs you connect in series, the higher the voltage. Unfortunately, the pricing increases with the voltage as well.

wow 16x10w you must have a very big tank, 5x10w i feel bit too bright for my 3 ft tank already

[zonerx]

Have you tried looking this supply "9.52V 5.25A". You need not to purchase any resistor

what so special about this psu?

i tested 12v 5a psu and is dead after an hour due to overheat...