Comments on: Mains operated LED lamp

By: VINOTH.S

VINOTH.S — Sun, 05 Feb 2012 08:34:15 +0000

Sir, i want to connect 50 led’s in series connection. is it posssible with four IN4007 diodes,474k 250v capacitor,and a resistor of 2.2Mohms.pls tell the circuit design.

By: virender

virender — Sun, 15 Jan 2012 19:22:11 +0000

Hi all, can anyone please tell me how to make 50/100 watt with 1000 Leds (White) using transformerless power supply. Any reply shall be highly appreciated. Thanx in advance! Please mail me to “vrndrsngh85@gmail.com”

By: shobha kumari

shobha kumari — Mon, 26 Dec 2011 06:57:49 +0000

battery voltage state indicator.

By: arun

arun — Wed, 21 Dec 2011 16:16:51 +0000

Dear Seetharaman,
Hello!!
Having just come across your site i find in your posts a wealth of information.You are doing a great job.Hats off to you.
As a CSR project for the BOP we would like to produce 5W/8W AC LED bulbs using 20mA, 3.2V smd LED’or 50mA, 3.2v smd Led’s.Is it possible to make these bulbs with your circuit to operate directly on 220V AC and without using constant current drivers.If yes can you suggest suitable circuits?
What will be the effect of such a circuit arrangement on the Power factor, THD and CRI.?
Is your circuit able to take care of voltage fluctuation which is a sad reality in India.
How is the current kept within the safe operating limit of the LED’s.
Your guidance will be highly appreciated.
Thanks
Arun
bestbrand@gmail.com

By: arun

arun — Wed, 21 Dec 2011 14:04:23 +0000

What will be the THD(Total Harmonic distortion) and PF
Can this work for a high power LED say upto 8W having a string
LED’s in a configuration of 40 x3

By: Seetharaman

Seetharaman — Thu, 10 Nov 2011 20:06:37 +0000

Hi Bhuvnesh Using 50LEDs in parallel will ammount to 1.25amps requirement you have to raise the capacitor C1 value to 25uF 400volts AC. will be a costly proposition, instead you connect you LEDs in series and use in the following circuit
http://www.circuitstoday.com/mains-operated-led-circuit reduce 1uF 400volts to 0.47uF 400volts.

By: bhuvnesh kumar

bhuvnesh kumar — Thu, 10 Nov 2011 10:34:25 +0000

dear sir thanks for this great ckt.
sir i want to connect 50 LEDs. then what will be
the value of resistance and capacitors in the ckts.

By: Feranando

Feranando — Fri, 14 Oct 2011 02:48:14 +0000

podrian ser amables de publicar la fotografia de la placa PCB,para asi poder armar el circuito ,ya que no entiendo mucho de electronica soy autodidacta,o mas bien dicho grafico de antemno muchas gracias.

By: seetharaman

seetharaman — Sat, 24 Sep 2011 23:54:09 +0000

Hi Rohith it is 0.5watts minimum

By: Rohith

Rohith — Sat, 24 Sep 2011 13:25:49 +0000

Plz… Tell me, which wattage resister (R1) is to be used for this circuit… ?