USB fading star

this circuit uses a 555 timer IC and BC547 transistor which are cheap and commonly available and works on usb   

Step 1 Parts list

1   x NE555
1   x BC547
1   x 33K resistor
1   x 500 r variable resistor
1   x 9V battery
24 x LED red ( or other colors) 
  

Comments

[bduncan5]

just wondering but i wanted to use this same wiring technique for another lighting project, is the fading automatic on the star? i am looking to make 2 led's light up and fade in a speed similar to a slow heart and the is the fade instant like a lightbulb or can you see it fade, if anyone can answer my questions that would be greatly apreciated, also if there is a video on youtube of the project or similar that would help too.

I am looking to make a steampunk light that pulses like a heart beating for my girlfriend for christmas.

[sooraj619]

fading is automatic fading, is not instant, we can see it fade

[bduncan5]

Thanks so much, this is exactly what i was looking for then, what is the rough time it takes to go through a cycle? from full on to faded and back to full on?

[sooraj619]

around 3 seconds

[bduncan5]

Alright, thanks so much, 5 stars :), you have been very helpful, keep up the good work.

[nodoubtman]

Hello! Good project!... But ... usb is limited to 5 V 100 mA, and your project cannot lit 24 red leds without reaching more than 100 mA..

how do you do?

thanks!

[sooraj619]

it works fine it lits up all the LEDs

[Monoplay796]

So this project will not work with the usb?

[sooraj619]

the circuit works fine.....

[Monoplay796]

Can someone please link me to where i can buy a variable resistor that could be used in this circuit?? And where does the circuit board go? kinda confused, this is my first build from this site (: