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555 astable driver to use as a twinkler

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For the life of me I cannot find a circuit design to use as a twinkler effect to operate a 15 watt x 12 volt LED. Can someone assist me?
 

Here is what I know; 30 to 50 hz freq. I think about 98% on with 2% off creates the twinkle effect. I have no waveform to post. Thanks
 

You can breadboard some Schmitt trigger oscillators using CMOS gates or 555 timers. But the best effects are pre-programmed sequences in an embedded uC sold with outside xmas lights.
**broken link removed**
 

That would not give the "twinkle" effect. It gives a sequential effect. By twinkle I mean about 98%on and about 2% off(like a distant star).
Thanks
 

response123 said:
**broken link removed**
The above given link may be helpful of what you are looking for. Best of luck
Click to expand...

every time whenever u power it on u need to select mode 7 to get twinkle effect. by default Random mode will give light effect of all modes.


for 555 Astable time calculator

http://www.ohmslawcalculator.com/555_astable.php

try with low freq. 30 or 50 Hz twinkling will be very high speed. try with less than 10Hz. It'll be good.
 

Thanks!
Questions:
Is driving it with 12 to 14 VDC ok?

How do I select mode 7 ?
 

98:02 This ratio at 30 - 50 Hz is very difficult to perceive. I think there is something missing or wage. Twinkling like stars may need different combination !!!
 
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Huh!!! I not understand that.
 

Here is what I know; 30 to 50 hz freq. I think about 98% on with 2% off creates the twinkle effect. I have no waveform to post. Thanks
Click to expand...

You need 30 - 50 Hz with 98% ON time and 2%OFF time.
Can this type of effect be perceived by normal human is the question.
This means that can one see this as twinkling?? It would look continuously glowing.
 

If you are familiar with micro controller use some small/basic uC like PIC10 series or PIC12 series. You can create random pulse at different freq which will give very good twinkle effect. This will give good look and attractive. u can re-prog it whenever u want to change the pattern.
 

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