CD4026 IC become very hot

[gophert]

Is the chip CD4026A or CD4026B?

 

[ChrisP58]

I suggest double checking the polarity of the power supply connections at the CD4026. The only time that I've had a chip get as hot as you describe is when the power was connected backwards.

 

[target1plus]

Why don't you show the very important supply voltage?

5V with a power supply. I ve tried a 9v battery directly also.

 

[target1plus]

Is the chip CD4026A or CD4026B?

CD4026BE i dont know what is the E at the end...

 

[target1plus]

I suggest double checking the polarity of the power supply connections at the CD4026. The only time that I've had a chip get as hot as you describe is when the power was connected backwards.

Positive on pin 16 and negative on pin 8. Because I got an output on pin 12 I think it should be the good way.

 

[audioguru]

Digikey sells one real CD4026BE with through-hole pins for only $0.56US today. One surface-mount one costs only $0.46US.
Why buy fakes from "over there"?

 

[MacIntoshCZ]

Digikey sells one real CD4026BE with through-hole pins for only $0.56US today. One surface-mount one costs only $0.46US.
Why buy fakes from "over there"?

He said that he bought it from ali due free shiping.

 

[audioguru]

I noticed that Digikey has a special low cost shipping today of "only" $11.00US. It is 2-day shipping. How many months from China?
In the good old days I bought real parts at low prices from local electronic parts stores but today they are almost all gone.

 

[MacIntoshCZ]

0,5$ ic, 11$ shipping
my hour salary after taxes is 7$. ( I work as electrical designer)
welcome to Czech Republic.
In Russia salary in average is 2 times lower (but without taxes i guess)
There are worst cases china, africa....
So if its person from poor country it rather buys from those untrusted sellers (if its conveniently)
Personally i buy electronics from tme.eu, when i have long list to buy

 

[audioguru]

Here in Canada the minimum wage is $15/hour. An engineer makes at least $50/hour. Health care is free for citizens. Low income people get government money and seniors are given a pension and do not pay taxes. But food, fuel and housing are expensive. I bought my small home in a suburb of a large city 35 years ago and now it will sell for one million dollars.

Poor people in the world do farming or nothing, not electronics, but some electronics factories pay one bowl of rice each day.. In Cuba, the average wage is $30/month (12.5 cents per hour).

 

[MacIntoshCZ]

Here in Canada the minimum wage is $15/hour. An engineer makes at least $50/hour. Health care is free for citizens. Low income people get government money and seniors are given a pension and do not pay taxes. But food, fuel and housing are expensive. I bought my small home in a suburb of a large city 35 years ago and now it will sell for one million dollars.

Poor people in the world do farming or nothing, not electronics, but some electronics factories pay one bowl of rice each day.. In Cuba, the average wage is $30/month (12.5 cents per hour).

At least $50/hour?
I am only one employe in company (boss, me , his wife that doing nothing) i know prices of projects that i am working on. $50 hour in average is what i can make for company. Without taxes and health care i am working for $13 hour. Those differences across countries are terrible. Until world unification its impossible.
I dont have a degree. Its uselless in CZ. Companies will not pay you more here. They rather grab employe with more practice. There are not any decent schools to study anyway. Tons of ******** fields of study but no electrictity and magnetism... Books are my only way i guess .
unfortunately thanks to work I forget more and more...

 

[gophert]

Those differences across countries are terrible. Until world unification its impossible.

Its not terrible, its relative.

I am in the US, a coworker decided he would move back to India at 1/3 the salary because, in India, he could afford a housekeeper and a nanny.

I'm also surprised how much time people from lower-wage countries DONATE by creating content (posts) for a for-profit company like WTWH Media LLC, so WTWH can get higher google traffic so they can sell more ads at a higher price (which is meant to say, life is not too bad if you can donate time to a company).

 

[target1plus]

Here in Canada the minimum wage is $15/hour. An engineer makes at least $50/hour. Health care is free for citizens. Low income people get government money and seniors are given a pension and do not pay taxes. But food, fuel and housing are expensive. I bought my small home in a suburb of a large city 35 years ago and now it will sell for one million dollars.

Poor people in the world do farming or nothing, not electronics, but some electronics factories pay one bowl of rice each day.. In Cuba, the average wage is $30/month (12.5 cents per hour).

I'm from Canada also and I'm an Engineer but I don't make 50 $/h Anyway, I didn't bought it because I really need it. I just bought a hundred of components for a hobby so if it's not working and it is not because of me I will just pass to the next one. I just want to be sure I don't miss something before givin up.

 

[audioguru]

I have never bought cheap fakes. All the genuine parts I bought locally work perfectly. It must be frustrating to have fake parts that do not work.

 

[MacIntoshCZ]

I have never bought cheap fakes. All the genuine parts I bought locally work perfectly. It must be frustrating to have fake parts that do not work.

I would be so much happy if i could buy parts localy! Nearest shop was in Liberec 60 km from my home. I think thanks to covid it doesnt exist anymore....

 

[rjenkinsgb]

Back to the 4026s:
Targetplus - Do they get hot if you ground the inputs and connect power but leave all the outputs disconnected.

 

[target1plus]

Back to the 4026s:
Targetplus - Do they get hot if you ground the inputs and connect power but leave all the outputs disconnected.

When there is nothing on the output, it's fine. With a 1k ohm resistor on one output it become very hot with plastic melting odour. If I remember well the ohm law, it should be only 5mA total in this condition?

 

[audioguru]

The datasheet of the CD4026 in post #11 shows that with a 1k resistor to ground on an output and a 5V supply, the output is 3V and the output current is 3mA. Then the output transistor has 2V across it and 3mA in it making heating of only 6mW which is nothing.
If the supply is 9V with a 1k resistor to ground on one input then the heating is typically 18mW which is also nothing.

Maybe it is not a CD4026 but instead is something that gets hot when one pin (an input?) has a 1k resistor to ground.

 

[MacIntoshCZ]

I would suggess you to buy one real chip to compare....

 

[ChrisP58]

Ok, You've said that with the chip powered, but no loads connected the part isn't hot, so let's start there with some diagnostic tests.

1) When in it's reset state, the output lines that would show a "0" (zero) should be high. Use your voltmeter to check those pins. The pin for the unlit segment should be low.
2) Now press the increment button and again check the pins. (*)
3) Repeat step 2 for all possible counts,
Do the high and low states of the pins match what they should be in each number?

* Note. Unless properly debounced, pressing the clock button will generate more than one increment pulse. That's what the 555 timer chip in some of your reference circuits does.