convert 220 AC to 3.6 VDC for lighting LED

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Pakistan:
No electricity.
No petrol.
No food.
No jobs.
No life!

Everywhere else this is the year 2009, not 1709.
 
Just found cheap and easy 240vac to 9vdc power supply.
Bought a motion sensing security light for $13.
Inside is the motion sensing circuit board and a transformer board.
Mine delivered 9vdc to the motion sensing board. I don't know if all operate on the same voltage.
Used an old power cord form a broken vcr and connected to my breadboard.
My white led was rated at 3v, so I just connected a 1K resistor and there you are.
 
220ac LED

Hi I found one circuit
 

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230 Volts LED

YouTube - 230 Volts LED and schema

Attached is a link to a 230 Volts LED in my test rig, with and without the 1N 4007 diode, showing the shift in current, less heat in series R.
The R can easily be changed to allowe for 20 mA's if required.
 
Hello guys, I was looking the treads to see if someone has made a simple Ac monitor led, is for my power supply that is a little far away from me and I need a led monitor to see if the PS is working.
I saw the formulas for Xc and I'm interested to know why you not considered the dropping of 0.7v of the diodes and also the input AC voltage should be considered RMS or peak ac voltage?

My AC line is 120vAc at 60Hz.

Could someone can explain me why?
Thank you for your time.
 
You should calculate for RMS unless the peak voltage will violate the electrical specs of your LED. Why don't you use a simple incandescent bulb? A small night light bulb would work nicely.
 
A couple of years ago I bought a package of 24 clear Christmas tree lights on sale after Christmas because they make perfect 5W night light bulbs. But They last only 2 months if you stay away from them or a couple of days if you unplug the night light which shakes and breaks the fragile filament.

Now the bulbs are gone and I made some LED night lights.
 
Thank you Sceadwian for your kind input and advice, but the room of my power supply is too small and I need something smaller.
I imagine that for the type of led and for the purpose the diode voltage should be insignificant but I think if we make calculus for peak voltage of 117vAc the led will long last, don't you think?

In my calculus 117 rms x √2= 165.46vpp

Current for the led 16mA

therefore R= 165.46vpp/0.016A

R= 10341

So R=10Kohms commercially.

I do not pretend to show off, I just want to know if this could be correct in order to be safely and a long life of led.

Please, if I'm wrong let me know, I would appreciate your input and everyone here will learn about our mistakes right?

Greetings
P.S. Excuse my english and spelling, I'm still learning.
 
A cheap no-name-brand LED operating at a fairly low current fails in a couple of days. A good quality LED made by a name brand manufacturer operates at 20mA for many hundreds of thousands of hours.
 
One often overlooked possibility is using a standared mini neon bulb. They run at line voltage and last for 10's of thousands of runing hours. And they come in red. orange, yellow, green, and blue. And they fit in the same space as a standard 5 mm LED socket.
plus they are only 1/8 to 1/4 watt. A package of two typicaly costs around a $1 or so.
 
I'm sorry guys, I did not recieve any email notification so I did not write to tell you that I have the right circuit for my power supply.
Thank you all for your help and inputs.
I have the circuit and I will upload so everybody can see it.

Again my apologizes for not write soon.

Thank you.
 

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hi
some power generation tip
visit any automotive junyard nearby you and collect any capacity alternatre (not dynamo) from any car
next mount alternater in such way that rubber belt can drive alternater from rear rim of cycle
connect alternater to 12 volt 7Ah battery
paddel the cycle and battery will get charge
you can run led based light for 12 hours on sigle charge
 

also Dhaka, Bangladesh on the same power cut problem.
 

Dear sir,

can i get ur dia of the LED lamp?
 
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