Hi all,
I have one of these LED chaser boards:
http://www.allelectronics.com/make-a-store/item/AEC/LED-CHASER-KIT/-/1.html
and I find that it's behavior is inconsistent. When I power it up, it will usually light LED2 (it never starts on LED1), and occasionally two or more LEDs will light. After a couple of cycles it will fall into a 1 - 10 sequence, but I need it to do this right from the start. There's not a lot of documentation on the circuit aside from bare-bones assembly instructions.
I did make some modifications: the 4.7uF cap on the 555 timer was replaced with 100uF to slow down the cycling (positive leg attaches to Pin 2 of the 555, the negative to Pin 15 of the 4017 and is also grounded). I also have attached a 100uF cap and 1K resistor to each LED to allow a slow fade when the LED is powered down. A 1N4148 diode is attached to the positive lead of the LED to prevent the cap discharging to the positive bus. Has anyone seen this kind of behavior in this type of circuit? If so, I'd like to know what I could do to fix it. Thanks in advance for all advice.
Gary
I have one of these LED chaser boards:
http://www.allelectronics.com/make-a-store/item/AEC/LED-CHASER-KIT/-/1.html
and I find that it's behavior is inconsistent. When I power it up, it will usually light LED2 (it never starts on LED1), and occasionally two or more LEDs will light. After a couple of cycles it will fall into a 1 - 10 sequence, but I need it to do this right from the start. There's not a lot of documentation on the circuit aside from bare-bones assembly instructions.
I did make some modifications: the 4.7uF cap on the 555 timer was replaced with 100uF to slow down the cycling (positive leg attaches to Pin 2 of the 555, the negative to Pin 15 of the 4017 and is also grounded). I also have attached a 100uF cap and 1K resistor to each LED to allow a slow fade when the LED is powered down. A 1N4148 diode is attached to the positive lead of the LED to prevent the cap discharging to the positive bus. Has anyone seen this kind of behavior in this type of circuit? If so, I'd like to know what I could do to fix it. Thanks in advance for all advice.
Gary
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