Simple Counter using CD40192BE to LATCH TO 7 SEGMENT (CD4511BE)

[wfg42438]

From the photograph, I would be surprised if it DID work!

You absolutely MUST connect a decoupling capacitor across VSS and VDD. The reason is that although CMOS ICs draw very little current when in a fixed logic state, they do draw a 'spike' of current as the logic levels change. It is caused by the internal capacitance of the transistors having to be discharged and recharged as the voltage on them changes to the other level. Even the tiny inductance of the wires to the supply, and deficiencies in the supply itself will cause a drop in voltage by the time it reaches the VSS and VDD pins. The drop will be very short, maybe only nanoseconds long but it can be long enough to upset the internal circuits of the IC. Placing a capacitor very close across VSS and VDD gives it a reserve of power exactly where it is needed and help to preven the dip in voltage.

Brian.

If im not mistaken these caps have to be 0.1uF is that right?

Also would i need these caps on the VDD and VSS pins of all counters and decoders i decide to use?

Aside from these caps missing is there anything else that stood out?

 

[betwixt]

I couldn't see anything else wrong.

The caps ideally should be across each IC, it is normal practice in logic design to include one capacitor of around 100nF per IC and also ones with a larger value maybe once per 10 ICs although I would consider it good to have at least one large value in the circuit even if you didn't have that many ICs. There is a compromise, a larger value will be better for holding a reserve charge near to the IC where it is needed but larger value capacitors tend to lose performance at higher frequencies (= poorer at handling short voltage dips). The solution is a mix of small capacitors close to each IC and larger ones distributed occasionally. The values are not critical, anything is better than nothing but 100nF and 10uF are good choices for most applications.

Brian.

 

[wfg42438]

I couldn't see anything else wrong.

The caps ideally should be across each IC, it is normal practice in logic design to include one capacitor of around 100nF per IC and also ones with a larger value maybe once per 10 ICs although I would consider it good to have at least one large value in the circuit even if you didn't have that many ICs. There is a compromise, a larger value will be better for holding a reserve charge near to the IC where it is needed but larger value capacitors tend to lose performance at higher frequencies (= poorer at handling short voltage dips). The solution is a mix of small capacitors close to each IC and larger ones distributed occasionally. The values are not critical, anything is better than nothing but 100nF and 10uF are good choices for most applications.

Brian.

I will go ahead and replace the leads at VDD and VCC with caps as suggested

Now i do have limited access to caps at school unfortunately however i have multiple 0.1uF ceramic caps at my disposal so i will use these for now

Ill get back to you to ASAP, thanks again!

 

[eetech00]

I will go ahead and replace the leads at VDD and VCC with caps as suggested

Now i do have limited access to caps at school unfortunately however i have multiple 0.1uF ceramic caps at my disposal so i will use these for now

Ill get back to you to ASAP, thanks again!

HI

Don't replace the leads, leave pin 16 connected to +V and pin 8 connected to GND
Best practice for digital IC's is to connect a 0.1uF cap from the +supply pin of each IC to ground. You don't need it on the GND pin.
If there is a -supply pin, connect one from it to ground also.
These "Bypass Caps" prevent noise from getting into the power supply pins of the IC. The chip is very sensitive to noise and the noise can cause erratic operation.

Unused input pins should be connected to +v or gnd depending on the resulting output logic state.

 

[Warpspeed]

Also get yourself a few spare ICs.
Its pretty easy to blow up CMOS, especially with breadboard type experimentation, and I think that may be the basis of your whole problem.
You are not alone, in blowing up chips, its quite easy to do and it can be very frustrating when something fairly simple that should work doesn’t.