How to make string LEDs?

[ahsrabrifat]

I see long string LEDs at wedding venues. I also see the small ones at homes for decorative purposes. I would like to make one by myself. But I don't know how to proceed. My main concern is, do I have to connect the LEDs in series or parallel? Another question is, normally, an LED runs at approximately 3V DC. But these LED strings that I am talking about run at 220V AC. What makes these strings capable of running at AC? Can anybody explain? Any suggestions are welcome.

 

[Diver300]

LED strings are almost always in series to get the total voltage of the LEDs near the supply voltage.

For instance, 12 V strings will have three LEDs in series, and a resistor to control the current.

LED lamps that run at 220 Vac contain rectifiers and many, many LEDs in series to get a large voltage. There are various different methods used to control the current. It is rare to have 220 Vac directly connected to LED strings. There is often a control box somewhere.

 

[ahsrabrifat]

LED strings are almost always in series to get the total voltage of the LEDs near the supply voltage.

For instance, 12 V strings will have three LEDs in series, and a resistor to control the current.

LED lamps that run at 220 Vac contain rectifiers and many, many LEDs in series to get a large voltage. There are various different methods used to control the current. It is rare to have 220 Vac directly connected to LED strings. There is often a control box somewhere.

Does the control box consist of only one rectifier circuit that runs 100 LEDs?

 

[Nigel Goodwin]

Does the control box consist of only one rectifier circuit that runs 100 LEDs?

It depends entirely on the specific design, many such strings use NeoPixels so are multicoloured, fade-able, and can run patterns. Even plain single coloured LED strings could well have a switch-mode driver.

 

[shokjok]

A closer look inside the LED strings reveals flat or low-profile LEDs connected as Diver300 described. I don't know who supplies flat LEDs, and this project will be time consuming. I made name-in-lights displays in 1988 using regular domed LEDs, CMOS ICs, and a 9VDC wallpack - unknown how many still exist.

 

[Nigel Goodwin]

A closer look inside the LED strings reveals flat or low-profile LEDs connected as Diver300 described. I don't know who supplies flat LEDs, and this project will be time consuming. I made name-in-lights displays in 1988 using regular domed LEDs, CMOS ICs, and a 9VDC wallpack - unknown how many still exist.

Everyone?, they are simply surface mount LED's - probably far more common now than through hole ones.

However, if you want an LED string, then just buy one - it's cheaper than buying the individual LED's.