Just to say hello to all ive just, practically justv registered.

 

Hi all,

there is practically no other way than connecting just three inputs of a 4017 somewhere. They are all important for proper function of the chip.

The input pins (in sequence) are: pin13 (ClOCK INHIBIT), 0=ENABLE CLOCK, 1=DISABLE CLOCK; pin14 (CLOCK), self explanatory, a counter without a clock signal can't count; pin15 (RESET), 0=RUN, 1=RESET.

According to the describtion of the malfunction I analyse reverse polarity for the power supply, in other words "CD4017 - RIP"
Basic rule in electronics: Before applying power to a new circuit check the power without ICs. Can also be done on a breedboard using IC-sockets. Power down until all voltages on the board have deminished. Insert the ICs and run. (saves some money too)

Boncuk

 

Hi pr0ff,

welcome to the forum. Congratulations for successful registering. Is there any relationship with the thread here?

Boncuk

 

It also depends on additional factors, such as distance from the power supply, how much local decoupling (or mass) capacitance there is on the board, types of chips being used, etc. Certain logic families specify how much bypass capacitance is needed, per how many chips. Some IC types need more bypass than others, for example synchronous logic parts, whilst some families need one bypass cap per IC when others don't.

For example, National Semiconductor application note AN-375 for HCMOS parts stipulates 10nF per every two to five packages spaced within 12cm, 100nf for every ten. That would be in addition to local board decoupling of, say, 50-100uF of aluminum electrolytic, or 10-20uf tantalum.

__________________
Corey

Rapp's Law of Inanimate Reproduction:
"If you take something apart and put it back together enough times, you'll eventually have two of them."

 

Modify my circuit, replacing the optos with relays.

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