Rotating LED circle, self contained project help.

#12

Joined Nov 30, 2010
18,224
That's why there is a place to enter your location. Go to the top of the page and click on "USER CP" then find where to write in some description of your location. That makes it easier for us to know where you can get parts.
 

KJ6EAD

Joined Apr 30, 2011
1,581
You should be aware that the MK107, like many Velleman LED kits, uses low current LEDs (~2mA). You will have to make some modifications to drive blue LEDs at 20mA using 12V. The CD4015 may not be able to source enough current. The data sheet is ambiguous on this matter.

Update
The CD4015 operation becomes erratic when driving loads exceeding ~15mA (Vcc=12V).

The MK107 will not reliably self start; it must be manually reset with a button push. It also must have the sequence manually clocked into the shift register with a button push and hold. Typically this is done by setting a very low clock speed to clock in the sequence and then adjusting the clock speed up to the desired run frequency.

Because of these difficulties, I recommend the 555/4022/2803 circuit for your application.
 
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