student1616

hello all,
as the title says,i want to make led based turn indicator for my motorbike rear view mirrors.
pls have a look at the below pic :
http://img98.imageshack.us/img98/537...apimagefg2.jpg

so when i power on the circuit the led's shld glow in pattern of 1+2+3+4+5+6
and when i reset the power same pattern shld repeat.

why i said power bcz,i'll connect this circuit parallel to the turn indicator.so when when i switch on turn indicator those led's will glow one by one.

can u guys help me with the circuit.
(smaller is preferred so that it will fit in the rear view mirror housing)
thanks in advance

Darth Bagel

The picture isn't working for me.

steev

above link is working.
i uploaded it to another place
http://www.pichost.ru/show.php/20040...gefg2.jpg.html

Cry_Wolf

simply use a 555 to generate clock for a counter that counts (1 3 7 15 ...)
i.e, (0001 0011 0111 1111 ...) in binary.Or SIMPLY use a microcontroller or a PIC..

__________________
Khizer Naeem Mughal
IIUI

steev

thanks.
iam kinda dumb at understanding logic stuff.
can u guide me towards some circuit idea,so that i can build one.

Roff

Do you want only one LED to be on at a time , or do you want each one to stay on until the sequence starts over?

__________________
Ron

steev

yes the 2nd one.
1+2+3+4+5+6 these will stay on.and when i reset the power the sequence will start from 1.

Roff

Steev/student1616, how come you have two identities? Is one your alter ego?

__________________
Ron

Roff

Seems like some sort of flashing would be more likely to get your attention.

__________________
Ron

Helder Ferreira

Use 6 small npn transistors with the emiter to ground, connect a 470 ohm in series with a led to each transistor's colector to the +ve line. Now connect a 2,2k resistor to each transistor base. Now find 5 zener diodes with aprox. equal value spacing between 5,1v and 8,5v (eg. 5.1 5.6 6.2 7.5 and 8.5) you can adjust values later. Connect these zeners in reverse bias in series with the 2,2k resistors to the base of the transistors. 1º transistor no zener, 2º 5.1, 3º 5.6...... 6º 7.5. Connect the cathodes of these zeners together with the base resistor of the 1º tr. You now have 6 leds that will be triggered by a raising voltage in the "base node". Now connect a 470 uF 25V electrolytic capacitor - to ground, + in series with a 10Kohm trimmer to +ve line, connect a 1n4001 diode in paralell with the trimmer cathode to +ve 12v, anode to capacitor side. When you power up, the capacitor slowly charges through the trimmer and fast discharges through the diode. Now connect the "base node" to the capacitor, trimmer, diode junction.

System theory: when the system is energised, the 470uF capacitor charges through the trimmer, as it reaches the zener voltages, it triggers the transistors. The 1º transistor does not have a zener so it lights up almost immideatly. You can regulate the speed by adjusting the trimmer. When you power down the capacitor quickly discharges through the diode. The system is ready for next cycle.

I hope you understand. Pardon my spelling.

steev

let me explain.
the project we are working.is modification of motorcycle.
for this college project i(student1616) created 2 logins to this forum.i kept this login for myself,and use it at home and the other login we use it at college.some time i post the replies from college itself.there the mistake happens.
and way i hope u guys don't mind.

@Helder Ferreira
thanks for the detail explanation.iam trying to make a rough circuit diagram,for what u explained.if u have the same pls do share with me,i'll compare it with my circuit diagram.

Cry_Wolf

So what do you do you decide you wanna do it with transistors , 555timers or with pic/microcontroller ???

if do it with microcontroller you will need the follwing:

1-AT89C51 (Atmel microcontroller)

2-12 mHz crystal,two 33pF ceramic capacitors, 8.2K ohm resistor, 10uF electrolyte capacitor. These all are for running the microcontroller

3- 6 leds

4- LM7805 (voltage regulator to convert 12 V to 5V)

5- 6~10 lines of code in assembly or C language

__________________
Khizer Naeem Mughal
IIUI

blueroomelectronics

Don't forget to use daylight visible LEDs. Else you'll never see them in daytime.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

steev

thanks for the response.
exactly saying iam still thinking what to do.as i said space is a big issue for me,what do u suggest.
i have some pic's and a PIC programmer with me.like PIC16f84,10f200,16f628 etc..
these are my friends stuff,still i can uses them for my project.
if this project can be done with 555(less in size) pls suggest me some circuit(rough diagram).

steev

yes i planned for ultra bright orange colored LEDs.as the turn indicators has to be orange in color.