hi all,
is there any circuit for Running LEDs from an AC supply(230v)?
please help.
is there any circuit for Running LEDs from an AC supply(230v)?
please help.
thanks for the link Bill_Marsden, but its all about diode, i need schematic diagram because i want to use general purpose led's(i will use many to get enough light,in India high flux led are not available. )
Not my article, it is part of the online All About Circuits book. I have submitted an update however, on this thread. White LEDs are alive and well, and getting brighter, check out the Rebel series mention in the update, it is modern. If you go to the manufacturers website you can get complete specs, easy as pie.Bill, the circuit diagram in your article is good, but some of the other information is rather dated.
If you check there were schematics, and how to calculate for your application. Did you read the entire article on LEDs?thanks for the link Bill_Marsden, but its all about diode, i need schematic diagram because i want to use general purpose led's(i will use many to get enough light,in India high flux led are not available. )
I'll help, but we'll need more info. What is the AC power standards of India in voltage and frequency.
i am trying to get high flux LED from abroad ,How many LEDs do you plan on stringing together?
what is SQR2After rectification you have a peak voltage of 240V * SQR2. We forget the voltagedrop of the rectifierdiods.
Square root of 2 = 1.414, it is the value X line voltage that the caps will charge to, about 340vdc in your example.what is SQR2
doubt 1:what if input increased ?Whats left is the voltage drop you will have in the resistor limiting the current through the LED's. Ohms law will give you the size of the resistor.
a single diode is enough ? or i need 4(for bridge),You'll need a 600V (minimum), 1 amp, rectifier diode
Use four, bridge, 1N4007 will work wella single diode is enough ? or i need 4(for bridge),
can you give me diode NUMBER?
is this safe enough?You'll need a 600V (minimum), 1 amp, rectifier diode to protect the LEDs, a 3.3K 10W ballast resistor, and 50 LED's connected as follows:
can you provide me schematic250VAC HOT --> a-Diode-c --> 3.3K RES --> a-LED1-c --> a-LED2-c ...LED50 --> 250VAC NEUT
is this normal resistor?If you want to run a little safer, us a 6.8K, 5W resistor.
1: Use the maximum.doubt 1:what if input increased ?
doubt 2:is there any constant current circuit?
because in india voltage fluctuation is common thing and some time we are getting spike of up to 1800v hence it is better to build a constant current with spike protector
(I lost many LED's in th previous project before joining All About Circuits
her is the thread http://forum.allaboutcircuits.com/showthread.php?t=13493&highlight=tail)
sorry..! if i am asking silly doubts .
OK, figuring 25 pairs (back to back), you would drop around 75 volts (3 X 25). We'll use 240VAC at 50Hz at 20ma as a base line. 240 - 75 = 165.Hi Bill_Marsden,
sorry for the delay in replaying .
as it will take time to get high flux LED's ,i want to try general purpose LED's first.
the ratings are :3V 30ma (max)
and i want to use 50 such LED's OR suggest me how much i should use.
thank you