I am having problem with my counter.
I works proper but when i hold it in hand then it becomes working when i place it on a table or anything it starts counting itself.
whats the problem?
plz help me

 

Hello,

Can you post a schematic?

Greetings,
Bertus

 

this is the schematic

 

It appears that you have left the COUNT and RESET inputs "floating".

All CMOS inputs must be tied to either Vdd or ground, or problems like this can occur.

You could use individual 10k resistors from the COUNT and RESET pins to ground to avoid this problem.

 

i have added 555 clock to pin#12(count) & reset to vcc through 10k.
i still have problems like that.
help me plz

 

i have added 555 clock to pin#12(count) & reset to vcc through 10k.
i still have problems like that.
help me plz

It might help things if you place another 0.1uFd bypass capacitor very close to the positive voltage terminal on the 4-bit counter.

Check your wiring. You need to keep interconnectin wires as short as plausible.

hgmjr

 

ok SIR ill inform u after following u.
thnx

 

hello SIR,
I followed u & i added 0.1uf to the 4bit counter(14553) on vcc but i am suffering same problem.
plz help me

 

Hello,

Do you also have a 0.1 uF capacitor on the power lines of the NE555?
Is there a 0.1 uF capacitor on pin 5 (control voltage) to ground of the NE555?

Greetings,
Bertus

 

no sir i left 555's pin#5 floating

 

Sir i connected vcc & pin#4 to the sensor(optocoupler).
i placed 22uf on pin#2 & 6

 

i observe that whenever i touch any soldering point my counter becomes normal & when i dnt touch then i becomes abnormal & counts itself.
what does it mean of touching my finger to any soldering point?

 

A 555 oscillator causes 400mA current spikes on its power supply. That is enough to kill any counter circuit operating off the same supply.

 

You affect the parasitic capacitance and leakage resistance of the circuit.

Post your circuit.

 

Hello,

There is no need to start a new topic:
http://forum.allaboutcircuits.com/showthread.php?t=25259

As mik3 says stray capacity can cause the problem.
This can come from long leads.

Greetings,
Bertus

 

so what should i do for making circuit normal?
what's the relation of my finger with circuit?

 

this is the schematic;
what is the relation of my finger with circuit such that when i touch it becomes normal?
help me plz

 

Greetings yasir_666,

I have merged all your related and scattered threads into the original thread.

In the future, please keep related replies and requests for information in the same thread. Splitting them up into multiple threads makes it hard for those members following the thread to keep track of the discussion.

Thanks,
hgmjr

 

ok thnx hgmjr

 

Hello,

Can you post a photo on how you have build you counter?
The touching behavour can be related to the way you made it.

Greetings,
Bertus