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problem with Up/down counter

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aldwinellaECEA

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hi! im using a 192 as a counter and a 47 as a decoder, the circuit is supposed to count up is a normaly open switch is push, and count down when another switch is push,


the problem with the counter is that it counts up normally and when the down switch is press the counter flickers ( changes the display, lets say the counting up stop at 21, when the down button is push it the counter changes from 21 to 66 and after the flicker it counts down, 65, 64,)

What should i do?
need help ASAP,
 
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hi,
I have replied to your PM about this problem.
The switch 'noise' debounce 100nF and resistors are important in order to suppress random operation of the counter.

EDIT: Ref your 2nd PM
You can use ceramic or mylar caps, which ever type you have.

Please do not send me PM's requesting technical help.
 
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ok ok, im sorry, the resistor you are talking about is the 270 ohms connected to the 7 segment, by the way i'm using 5 inches 7 segment, is the 270 ohm enough or go much higher?
 
sir eric!
got a problem, it still flicker, when i press the button it jumps, it tried using the 100nf and 500nf?
what good thing to do?

can i also ask for a layout for count up and down century timer that is limited to 01 and 00,
actually my circuit is a controller for a parking system, if the timer hits 00 it will feed Logic 1 to the H bridge for rotating clockwise and counterclockwise,
i use the H bridge for controlling the Boom

btw, Layout Please
 
hi,
When you ask for a layout, do you mean a circuit diagram or PCB layout.??

For the limited count, do you mean not to count 'lower' than '00', I do not follow what you are asking for.?

Please post a clear photo of your counter layout that has the 'jumping' on the count when you press the switches, lets see what is wrong.
 
What Eric is saying, cheech your gosh darn layout looks real nice. All you need now is a application specific engineer, the circuit may be fine.
 
**broken link removed**

just enlarge it, thanks, i configure it to start at 30, in Proteus (ISIS7) it works well, but when i transfered it to the protoboard, the flickering starts,
it starts counting form 30, it can count up, and can count down,

The problem is from the transition of counting up to counting down, if the counter shows 15 and its counting up, when i change it to count down the number jump, from 15 to 23 etc.

i dont know what to do,
 
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yup, i made it as a guide, because, specifications where given to me,
**broken link removed**

i use 192 as counter 47 as decoder, AND and NOT gates to limit, 555 for clock pulse generation
 
It would be best if you explained to me 'exactly' what you want the counter to do and display.

You originally said a 2 digit up/down counter using push buttons, the circuit you posted has many AND and Invert gates
 
ok ok, this project is an UP and DOWN century counter,

the use of the gates is to limit at 00 and 01, but they are connected to MR reset, instead i will be feading it to an H bridge composing of 4401, which is connected to a motor

when the counter hits 00, the motor would turn clockwise and when it hits 01 it would turn counter clockwise,
 
ok ok, this project is an UP and DOWN century counter,

the use of the gates is to limit at 00 and 01, but they are connected to MR reset, instead i will be feading it to an H bridge composing of 4401, which is connected to a motor

when the counter hits 00, the motor would turn clockwise and when it hits 01 it would turn counter clockwise,

Hi,
For the operation you describe, ie: 0 1 State, all you need is a bistable [flip/flop], not a 00 to 99 counter.

Look at the operation of a CD4013 'D' type bistable latch.
 
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