LED Flasher (very Interesting.............)

yourwins

Apr 12, 2004
18
Joined
Apr 12, 2004
Messages
18
i got an idea with this flasher but do'not know how to design the circuit................

anyone who having the idea in designing the circuit , please share it to everybody.


Thank You.................................

 

MP1

Dec 7, 2003
3,399
Joined
Dec 7, 2003
Messages
3,399
It is here:

http://www.aaroncake.net/circuits/chaser.htm

MP
;D

 

audioguru2

Apr 6, 2004
12,026
Joined
Apr 6, 2004
Messages
12,026
Hi guys,
The Chaser circuit will not make the LEDs go back and forth like YOURWINS cool animation of a Knightrider. Instead the LEDs will start with #1, then #2...... up to #10, but the next LED will be #1, then #2 etc. The reason is that the 4017 can only count up, not down. That is why the circuit is called a CHASER. If you put the LEDs in a circle then they will go around and around in ONE direction only.
A Knightrider circuit will need the oscillator to be followed by an up/down counter, a flip-flop to change the direction, then a decoder.

This is just theory, but it is true.

YOURWINS,
Please post an animation of an LED chaser that is in a circle.

 

audioguru2

Apr 6, 2004
12,026
Joined
Apr 6, 2004
Messages
12,026
Hi again,
An analog circuit will make an LED Knightrider circuit:
1) A classic 2-opamp ramp generator (1st stage is a comparator with hysteresis and the 2nd stage is an integrator and the stages connect together with feedback).
2) The ramp generator feeds an LM3914 voltage-to-dot driver driving the LEDs in its dot mode.
The lighted LED will appear to continue to go back and forth.

Just more theory, guys.

 

MP1

Dec 7, 2003
3,399
Joined
Dec 7, 2003
Messages
3,399
yourwins, the article mentions the knight rider lights, so I would assume that it is what you want. In a little more searching I find there is also a knight rider circuit on our site:
http://www.electronics-lab.com/projects/motor_light/035/index.html

Then also here:
http://www.charlton.vic.edu.au/mark/electronics/555_projects/k-rider.html

...and here:
http://www.talkingelectronics.com/FreeProjects/555/555-P3.html

They all seem to be similar. Let us know if it is true that none will give you the knight rider effect as the authors claim.
My own favorite circuit would be to use a microprocessor chip.

MP

 

audioguru2

Apr 6, 2004
12,026
Joined
Apr 6, 2004
Messages
12,026
Thanks, MP:
Those circuits WILL light 6 LEDs in a Knightrider fashion. They use diodes as OR-gates, so that 4017's outputs #1 to #6 light LEDs #1 to #6 in sequence, then output #7 lights LED #5, output #8 lights LED #4, etc. and back down to LED #1, then it starts over again.
A brilliant use of diodes as gates. Don Lancaster (CMOS Cookbook) calls it "mickey-mouse logic", but it works well.

 

yourwins

Apr 12, 2004
18
Joined
Apr 12, 2004
Messages
18
Thank you for your information.

:D


i will try to make one , then i will post my problem if experiment not work.

 

steven2

Jan 19, 2004
1,698
Joined
Jan 19, 2004
Messages
1,698
;)as nice as it looks . the light chasser circiut has a good use. i biult a double one, that powerd .more than 90 leds but i used it as a lotto number picker, and by taping into the electro and by shorting it out via a push button switch i was able to stop the leds in there tracks ,thus determining the numbers to pick, the numbers were home made decal dots with the numbers written on them with a fine point marker pen. and surgically placed under each led with a pair of tweezers. as for the night rider scanner type if you like the circiut ill post it . and there used to be a similiar intresting one around called the cylon eye but i dont have the circiut for that anymore.

 
Top