4017 chaser leds

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mostaghfir

Joined Dec 29, 2010
10
pleas said me if is there a mistakes in this circuit shematic because if i select the position n° 1 for exemple some leds ordered by 2n2222 n°2 turn on despite their vcc is isolated ....I can't understand:confused: below the schematic:

Untitled - 2.jpg
 

KJ6EAD

Joined Apr 30, 2011
1,581
The transistor collectors should be connected to the cathode ends of their respective LEDs. All LEDs should have their own individual current limiting resistors. The outputs of the 4017 are numbered 0-9 coresponding to a 1-10 sequence. There may be other errors, but those are the most obvious.
 

Dodgydave

Joined Jun 22, 2012
11,285
the complet schematic (the first is incomplet)
View attachment 44314

The second and third set of Black leds look like they are reversed, the leds need to be connected with the cathodes to the transistors, each led needs its own resistor,also if your only using 3 outputs, pin 15(reset) needs to be connedted to to the forth output (pin 7) to give a better display.

try this first
http://www.qrp.pops.net/LEDs.asp
 
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