[S-V-K]

Hi,
I'm trying to build a led light and I'm a bit lost :-)

Here is my headache :-)

104 x 1W 0.35A LEDs consuming 309,4Vdc and 108.29W all of them are connected in series.

Power source: 150W ,, 120Vdc-410Vdc ,, Current 0.35A
https://uk.rs-online.com/web/p/solid-...hting/7227959/

Can I connect all LEDs directly to the driver or do I need some sort of resistor to reduce Vdc ???

THANK YOU VERY MUCH

[bonsai]

Nope, the driver should self-regulate to provide the stated constant current within the defined voltage range.

Make sure the driver case doesn't exceed 65°C (preferably 60°C), as the datasheet indicates this will dramatically decrease lifetime/increase failure rate.

[S-V-K]

Originally Posted by bonsai

Nope, the driver should self-regulate to provide the stated constant current within the defined voltage range.

Make sure the driver case doesn't exceed 65°C (preferably 60°C), as the datasheet indicates this will dramatically decrease lifetime/increase failure rate.

Thank you for a quick response :-)
I'm noob in electricity :-/

Driver is putting out 0.35A constant current.
I'm worried about voltage.

Leds consume 300Vdc and driver is working between 120-400Vdc.

[rives]

A constant-current driver should vary the voltage within it's designed range to keep the wattage constant.

[S-V-K]

Originally Posted by rives

A constant-current driver should vary the voltage within it's designed range to keep the wattage constant.

So am I good to use this driver ???

[rives]

Originally Posted by S-V-K

So am I good to use this driver ???

Without having all of the spec's on your LED's and how you have it connected, it is a bit of a leap, but if the the LED's are rated for that current level and you have enough of them in series to get into the the acceptable voltage range of the driver, you should be golden. I was a little unclear about the information in your first post regarding this. If you multiply the voltage drop across each LED x the total number in the string, you will get the total voltage drop. It should be between the 120-425 volts that the driver data sheet says it puts out.

[S-V-K]

Thanks for help

Please have a look at my first post where are all calculations
I'm using these LED :https://www.ebay.co.uk/itm/2807708325...ht_4755wt_1115

Blue LEDs are taking more voltage.


Thanks for help

[rives]

Originally Posted by S-V-K

Thanks for help

Please have a look at my first post where are all calculations
I'm using these LED :https://www.ebay.co.uk/itm/2807708325...ht_4755wt_1115

Blue LEDs are taking more voltage.


Thanks for help

I have looked at that post, and was confused by what you meant by it. If you have a series string, the voltage drop and current through each LED is going to be the same across each LED, so they need to have identical specifications. Are you saying that you have both red and blue in the same string, and the blue's require more voltage (that is normally the case)?


"104 x 1W 0.35A LEDs consuming 309,4Vdc and 108.29W all of them are connected in series" ???

The link for the LED that you posted shows the forward voltage drop to be 2.5-2.7v. If you have 104 of them in series, the total voltage drop through them would be 260-281 volts, so that part works. I'm not sure about the rest of what you are talking about.

[S-V-K]

Originally Posted by rives

I have looked at that post, and was confused by what you meant by it. If you have a series string, the voltage drop and current through each LED is going to be the same across each LED, so they need to have identical specifications. Are you saying that you have both red and blue in the same string, and the blue's require more voltage (that is normally the case)?


"104 x 1W 0.35A LEDs consuming 309,4Vdc and 108.29W all of them are connected in series" ???

The link for the LED that you posted shows the forward voltage drop to be 2.5-2.7v. If you have 104 of them in series, the total voltage drop through them would be 260-281 volts, so that part works. I'm not sure about the rest of what you are talking about.

You are talking to a noob mate

red 660 -DC Forward Voltage:2.5V~2.7V
red 620- Forward Voltage : 3.0V~3.2V
blue 440- forward V: 3.2V(min), 3.6V(typ), 3.8V(max)
blue 460- Forward Voltage : 3.2V~3.4V

104 of above mentioned leds together through one power supply.

Before you beat me with a bamboo stick - I have one similar light running at the moment without any issues(28 leds together).I mean mixed up voltages and connected in series.


Many thanks for your help

[alkalien]

Just make sure alle LEDs can manage 350mA and add up the drop voltages for all LEDs in series, the sum should be in the voltage window of your driver. You don't have to worry about anything else.

Combining different voltages would only be a problem if not in series but parallel.