Power led slot turn

Thread Starter

dragalic

Joined Dec 1, 2011
10
i have power led
10W
input 12V 900mA-1000mA

I want to make slot turn on and slot turn off of at least 10min
(when i turn on the let it should start slowly and for 10+min to get its maxium, same when i turn off)

is this posible, and if someone can give me some schematics,

thanks
 

Bernard

Joined Aug 7, 2008
5,519
Use a voltage controlled pulse width modulated[PWM] to control brightness, & triangle wave generator to control PWM, [ 555 ? ].
 

Wendy

Joined Mar 24, 2008
22,141
If you were a bit more clear as to what you want I could help.

I have a tutorial on the subject. You will have to learn to read schematics though.

LEDs, 555s, Flashers, and Light Chasers

Suggestion: enter your approximate location in your profile so it would show up on the posts, it helps people cater the parts to your needs.
 

Thread Starter

dragalic

Joined Dec 1, 2011
10
litl bad in english byt will make it more clear (will put location now)

its slow turn on/off
take a look at the video, i want that for at least 5-10min, (may be more if cant)
http://www.youtube.com/watch?v=gKykP936tWA
for power led
12V 900mA

i take a look there, but all its on normaln led 20mA (not something on 12V 900mA)

can this work and how much slow it could be
 

Wendy

Joined Mar 24, 2008
22,141
I helped a gentleman with something similar about a year ago. I'll point the thread out when I get a chance.

Several points though, when you turn the power off what is going to light the LEDs up while they fade? This means you will not be turning power off for this circuit. It is going to need power while the LEDs are on.
 

Wendy

Joined Mar 24, 2008
22,141
OK, we'll modify this schematic...



from this thread...

LED fade in/ fade out

from this post...

http://forum.allaboutcircuits.com/showpost.php?p=344698&postcount=49

I spent the 1st half of that thread correcting the same misunderstanding that I made about your request.

I will redraw this schematic when I have time to fit your needs, basically removing all the LED chains and replacing it with your single LED.

As with the other one, you will need 12 V on it while it is fading, which means permanently more or less.
 

Wendy

Joined Mar 24, 2008
22,141
While the LED is on it will have that draw. When it is fading it will not.

I do need to redraw the schematic. It will take about a day to get done.
 

Wendy

Joined Mar 24, 2008
22,141


All resistors are ¼W.

The current regulator LM317 and R9-R17 can be replaced with a commercial buck puck (google it) for much greater efficiency (as in a lot less current) and the LED will still get 900ma.

The LM317T will require good heatsinking, as it will get very hot at maximum brightness.
 

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Thread Starter

dragalic

Joined Dec 1, 2011
10
cool, so should i make example a or example b
couse the difirence ive seen its
or example b use 2 power suply, one for on/off and one for constantly suply the board

and u2b its lm393, right
 

Wendy

Joined Mar 24, 2008
22,141
cool, so should i make example a or example b
couse the difirence ive seen its
or example b use 2 power suply, one for on/off and one for constantly suply the board

and u2b its lm393, right
It is ½ of a LM393, the U2A is the other half. Some parts (capacitors and U2A) of the schematic are the same for both function, so I only drew them once.

Example A is for a toggle switch, Example B is for a second power supply to cause the LED to lighten and darken.
 

Thread Starter

dragalic

Joined Dec 1, 2011
10
thanks, i will try to draw the board and send here picture to take a look
about the power suply i use 1000mA and led need 900mA is it ok to use LM317 and R9-R17 and not searching for some commercial buck puck
and second power suply for turn on/off does need to be 1000mA or can be less, i got a lot 350mA adapters, so could use one of them
 
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