Impulse counter

[Frank7]

I got to make this school project.
This is how should it work:
I need to make circuit that will on every fifth impulse (f=1Hz) that I bring on entrance turn off LED which is located at output. When sixth impulse comes to entrance it must turn on LED and repeat that all over again.

Here is what i think how should i solve this problem:
I will use IC NE555 for generation impulses of 1Hz. Then i will bring that signal on Counter and after counter i will put divider. I will connect LED at outputs of divider so when 5th impulse comes at entrance it will turn LED off and when 6th impulse comes at entrance it will turn LED on again.
So its: 555->Counter->Divider->LED

Will this work ?

 

[ericgibbs]

I got to make this school project.
This is how should it work:
I need to make circuit that will on every fifth impulse (f=1Hz) that I bring on entrance turn off LED which is located at output. When sixth impulse comes to entrance it must turn on LED and repeat that all over again.

Here is what i think how should i solve this problem:
I will use IC NE555 for generation impulses of 1Hz. Then i will bring that signal on Counter and after counter i will put divider. I will connect LED at outputs of divider so when 5th impulse comes at entrance it will turn LED off and when 6th impulse comes at entrance it will turn LED on again.
So its: 555->Counter->Divider->LED

Will this work ?

hi Frank
Have you considering using a 555 1Hz astable to drive a 4017 counter/decoder.???

Place your LED and resistor on the 6th output pin and link output pin 7 back to the RESET pin of the 4017,

 

[Reloadron]

Configure the 555 as an astable multivibrator for your 1 Hz clock as you mention. Then use a 4017 decade counter/divider. Place an LED on Q4 and Q9 of the 4017. Use diodes (1N914) to connect the LED. Cathode side to the LED. Does that make sense? Check out the 4017 data sheet.

<EDIT> Beaten by Eric. with a better explenation. </EDIT>

Ron

 

[colin55]

10 LED CHASER
Here's an interesting circuit that creates a clock pulse for a 4017 from a flashing LED. The flashing LED takes almost no current between flashes and thus the clock line is low via the 1k to 22k resistor. When the LED flashes, the voltage on the clock line is about 2v -3v below the rail voltage (depending on the value of the resistor) and this is sufficient for the chip to see a HIGH. Put the LED on the 6th output and return the 7th output to the reset line. The flashing LED will let you know the number of pulses and the LED will illuminate on the 6th pulse.

(circuit designed on 9-10-2010)

 

[Frank7]

I think i cant use 4017.
It must be all in TTL group and 4017 is CMOS.
For counter i will use 7493 so i need only divider which will have LED at output right ?

 

[colin55]

Use can use a 7490 to divide by 6 and put the LED on the clock-line to clock the chip.

 

[Frank7]

Ill try to make this with
555->7493-> use logic gates (and, or, xor) to use that BCD code and make circuit that will give me 0 at output when counter count fifth impulse

 

[colin55]

I just told you . . . . you can use a 7490 to divide by 6.

 

[Frank7]

hi Frank
Have you considering using a 555 1Hz astable to drive a 4017 counter/decoder.???

Place your LED and resistor on the 6th output pin and link output pin 7 back to the RESET pin of the 4017,

My mistake... i can use 4017
Why put LED and resistor on the 6th output ?
I thought i need to put it on 5th (Q4) and reset pin on 6th (Q5) output.
So it will turn off when 5th impulse come at entrance right ?

EDIT: nwm i just saw it in datasheet It has to be LED on 6th and RST on 7th output thx

 

[ericgibbs]

My mistake... i can use 4017
Why put LED and resistor on the 6th output ?
I thought i need to put it on 5th (Q4) and reset pin on 6th (Q5) output.
So it will turn off when 5th impulse come at entrance right ?

EDIT: nwm i just saw it in datasheet It has to be LED on 6th and RST on 7th output thx

Look at this clip from the datasheet.
Note: Q0 is ON when the 4017 is reset, so count from there.
q1,q2,q3,q4,q5 = ON, q6 = reset

 

[Frank7]

Yes i saw that picture
I understand now

 

[Frank7]

Where did i made mistake ?
It should look something like this...
555 has output f = 1Hz

 

[ericgibbs]

Where did i made mistake ?
It should look something like this...
555 has output f = 1Hz

Hi,
Your drawing shows pin15 [reset] connected to 0V., it should only go to the 4017 output.

 

[Frank7]

ok
I did what u said.
I think i need to change R3=560 Ω
But it still dosent turn off on every 5th impulse. Something else is wrong too

 

[ericgibbs]

ok
I did what u said.
I think i need to change R3=560 Ω
But it still dosent turn off on every 5th impulse. Something else is wrong too

hi,
Whats the sequence of the LED that you are seeing.?

EDIT:
Pin 5 should only goto pin 15, no where else

 

[Frank7]

Sure ill upload new pic now
Its in that post before
LED is ON all time

 

[ericgibbs]

Sure ill upload new pic now
Its in that post before
LED is ON all time

With the LED connected that way, it will be ON most of the time.!

Connect the resistor to the 4017 pin, not the +9V

Like this

 

[Frank7]

Nope same thing.
I know that LED will be on most of time. It only must turn off when 5th impusle comes at input of 4017

 

[ericgibbs]

hi,
I will post you a full circuit diagram tomorrow OK

 

[ericgibbs]

Nope same thing.
I know that LED will be on most of time. It only must turn off when 5th impusle comes at input of 4017

Well with the circuit you have posted it will work as you want.

As I said I will post you a tested circuit tomorrow.