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Dynamic Christmas lights

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gabi68

New Member
Hi to all,

I try to find a best way (cheap schematics and parts) to make a dynamic Christmas lights form LED's (15-40 piece's). That diagrams must work on 220 V 50 Hz. I search onto forum and nothing came up. So, any advice (a diagrams will be awesome) will be appreciate.

Thank you
GB
 

Hero999

Banned
What do you mean by dynamic christmas tree lights?

Connect 20 12V bulbs in series, make sure all connections are well insulated and there you have it, a set of christmas tree lights.
 

gabi68

New Member
Hi,

I want that LED's to light up on a pattern. Let say 1,5,9 up then 2,6,10 up then ... and son on. Can you give an advice?

Thank you
GB
 

gabi68

New Member
Hi,

I know that but I try to make my own (at list I learn something). So, any diagrams (with PIC or anything else)...

Thank you
GB
 

Hero999

Banned
There are loads of different ways of doing it.

Generally, it's best to use a microcontroller to control different chains of lights.

Do you want to use LEDs or incandescents?

LEDs are probably the best way to go as you can power them from a transformer. Using a 24V 12VA transformer you could connect them in strings of about 10 and will provide enough current for 17 chains giving a total of 170 LEDs!

Small transistors like the BC548 could be used to control the LEDs from the microcontroller which could be powered from a linear regulator like the LM7805.
 

gabi68

New Member
Do you have a diagram for that ? As you say LED's are better. The only thing I am worry about is the heat. Do you know how much heat is dissipated form that LED's?

Thank you
GB
 

Hero999

Banned
I'll show you if you really want but I shouldn't have to draw you a diagram if you know basic electronics.

Do you know how to drive a relay from a PIC?

Just rip out the relay and flywheel diode and replace it with a string LEDs and an approprietly sized series resistor.

The only thing that might get hot is the series resistor and the power dissipated by it can be calculated using ohm's law, you know V^2/R or I^2/R.
 

Hero999

Banned

HarveyH42

Banned
Hot LEDs don't stay hot for very long, but then again they don't light afterwards either...

After Christmas, you can get strings of 35-40 LEDs for about $2.00 USD each. I got lucky last year and remembered to look for them. Got 3 strings all white, and 7 multi-color. All but 2 sets had full leads.

If you want to control 40 or more LEDs individually from a micro, look into multiplexing...
 

audioguru

Well-Known Member
Most Helpful Member
My electrical utility company gave away LED Christmas lights for free in exchange for turning in a string of power-hungry incandescent ones.

They were cheap Chinese ones and they were all recalled then replaced.
They are extremely dim.
 

Hero999

Banned
Sometimes it's better to build your own even if it does work out more expensive as so long as you design and build it to a high standard you'll get a high quality product.
 

audioguru

Well-Known Member
Most Helpful Member
Design a circuit to fade multi-color RGB LEDs and they make every color that is possible if they fade in a "random fashion".

My MOOD LIGHTS fade their red, green and blue LEDs at slightly different frequencies so the colors on the ceiling are all colors possible and at all brightnesses. The fading is very slow. It repeats in a few hours. It looks cool.
 
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