Power supply for 300 LED from AC

[janeceline]

Well where is the circuit diagram ? Any1 post it pls...

The circuit is for White LED of 3.5v approx.


60 White bright LED in series.

 

[Ubergeek63]

You mean commercial LED lamps have built in SMPS?

Offline ones do. Not the silly little night lights or book lights, but the actual AC lamps and quality power flashlights do.

 

[Ubergeek63]

A single red or green pilot LED requires only an 56K resistor across 230V. Normal LEDs have low brightness otherwise a bright type must be used. A diode resistance combination can be used for getting good brightness. Here resistance must be atleast 2W type.

Which would be great if we were discussing pilot lights.

We were discussing large quantities of junk LEDs run of the line. My point is that you can pay $50 to get "junk" whites to put out 500Lm for 20W or you can pay $25 to get lighting class LEDs to put out 500Lm for 5W.

Which would you rather?

 

[ketankhakhar]

I want to derive power supply for 270 LED's ( 1 rows of 10 LED's in series - Each LED 3.6v DC ). How to derive the circuit ? Any Idea ? Without transformers.

please give me an idea and circuit diagram of the same

 

[RODALCO]

220 - 240 Volts led lamp

https://www.electro-tech-online.com/threads/240-volts-100-hertz-29-led-lamp.96363/

Read above link.

I built many of these and this circuit is reliable.

You need to recalculate the R values for 55 LED's but the same principle applies.

 

[Ubergeek63]

please give me an idea and circuit diagram of the same

read the thread.... driving LEDs off the mains like that is inefficient in power and build time...as well as being prone to failure in long term service.

a little more power supply complexity gets a lot more light out of a only a few lighting class LEDs

 

[Upananda]

AC powered white led lamp

Dear sir

please show me the power supply for 60 LED from AC

Thanks
Upananda

 

[Ubergeek63]

Dear sir

please show me the power supply for 60 LED from AC

Thanks
Upananda

are you saying that you have hundreds of junk LEDs that you are just dying to use?

the best non lighting class LEDs are probably CREE P41s: Digi-Key - CP41B-WES-CK0P0154-ND (Manufacturer - CP41B-WES-CK0P0154) at $0.50 each and 74Lm/W. For 60 LEDs that would be 444Lm typical or about a 40W bulb for $30 without the driver.

Two **broken link removed** and one **broken link removed** for about $16 plus a good heat sink is a lot less money and labor for your light

 

[carmusic]

why using a transformer just see how chritmas led light are made, they are no transformer, no extra parts at all, just leds in series and maybe a capacitor or resistor. i would do it very easily, one bridge rectifer and one resistor per branch of led.

 

[Ubergeek63]

why using a transformer just see how chritmas led light are made, they are no transformer, no extra parts at all, just leds in series and maybe a capacitor or resistor. i would do it very easily, one bridge rectifer and one resistor per branch of led.

and they have to run at half capacity to make sure they do not burn out with voltage variation

 

[ronv]

Upananda,

Look at this link from post #25. https://www.electro-tech-online.com/threads/240-volts-100-hertz-29-led-lamp.96363/
Sometimes just ok is ok.

 

[tcmtech]

Here is the basic schematic of the circuits I have been building and have had several of them running continuously now for about 6 -7 years now.
You will have to calculate the voltages and values for the two capacitors and R1 can be any where from 100 to 1K ohms.