While i was surfing on websites, i saw this circuit. Although i did whatever it says, i couldn't operate it, i mean i couldn't run the circuit for my project. Could you help me to find where the mistake is? If you will, it will be a glad to me.
You forgot to say exactly what your project does or does not do. The schematic is correct but is missing an important supply bypass capacitor from +12V to ground. Use 10uF to 100uF. The 1N4148 diodes do not do anything and can be replaced by pieces of wire.
Maybe you have the diodes, LEDs, transistors or ICs connected backwards. Maybe you connected C2 with its polarity backwards. Maybe you connected the power supply polarity backwards.
Looks like that schematic was designed for white/blue LEDs judging by the transistors used when the 4017 can drive regular red/green/yellow LEDs directly ( http://www.aaroncake.net/circuits/chaser.asp ).
Break the circuit down into sections. Check that the 555 is oscillating, then theck that the pins on the 4017 are sequencing. Then check each transistor to make sure it's base is receiving the pulse, etc. etc.
I need help about this sequential led line circuit
Posted - Aug 09 2010 : 6:36:54 PM
By accidently, i connected ground cable to leds so the circiut doesn't run. 