#1230

Episode 1230 chip of the day 4017
A look at this chip and some discussion about digital logic
Be a Patron: / imsaiguy

[@user-eo5ny9ww4m]

I don't think the circuit is drawn wrong. It is a Clock Inhibit input, not a Clock Enable. If the Clock Inhibit is high, the bottom input to the NOR gate will be high, so the output will always be low. That will prevent the clock input from toggling the output of the NOR gate. When the Clock Inhibit is low, the clock signal will be allowed to toggle the output of the NOR gate.

[@jerril42]

Must be careful not to be an enabler 🙃

[@MyProjectBoxChannel]

I love the 4017! even in this world of cheap microcontrollers. I don't think I'll ever stop using it. It's a bit like the 555, it always comes in handy in my bag of circuit tricks👍😉 sometimes I use a flashing LED as a simple clock for the 4017.

[@mickgibson370]

I build an electronic rpm meter back in 80s that would 1/100 rpm in a minute. Dam machines was so irregular that the rpm was 60.12 and the next second 45.68. I memorized the logic and when you show the picture of the circuit, I still have it even I have a stroke 28 years ago.

[@mikegLXIVMM]

I've used this chip as a frequency divider. You divide by 2-10 based on where you tie the reset.

[@RideGasGas]

Back in the Army when we were learning about the satellite communications equipment, there was a piece of gear called the SSLU, system status and logic unit. It was discrete logic and all NAND gates and inverters. Cards and cards of them. We learned logic tables and they described De Morgan's theorem to us and how to get to basically anything using some combination of inverters and another gate type. Pretty mind blowing at the time for young kid just learning digital for the first time. Then along came PLDs, one little chip, and all sorts of possibilities replacing a whole handful of logic chips :)

[@jstro-hobbytech]

I've read the Don Lancaster books and learned all that with the karnaugh maps and such. I was obsessed with it a while back haha.

[@andymouse]

Classic chip ! perfect for making a Larson Scanner better known as a "Cylon" eye or of course the knight Rider lights, in fact I believe in some EE courses they ask you to make the Knight effect with hardware and also ask you to make the same in software which is a neat task for any beginner....love your 'chip of the day'...cheers.

[@Enigma758]

With a little diode steering, you can make them output any pattern you like. I've used them for sequencing unipolar and bipolar steppers.

[@nickcaruso]

what happened to the circuit from china? :-)

[@jerril42]

Interesting chip and logic demonstration. I looked up DeMorgan's Law on Wikipedia. I think the Text Search implementation of the law helped me to understand it: Search A: NOT (cars OR trucks) Search B: (NOT cars) AND (NOT trucks)

[@X-OR_]

A Very Logical Episode !

[@t1d100]

Thank you.

[@M0UAW_IO83]

Oh I made a good amount of pocket money with these chips, I made LED Knight Rider lights for schoolmates and later sequential tone roger beeps for CB.

[@vincei4252]

Yeah, totally agree that the logical implementation of the internal circuit should have been shown in the data sheet as opposed to the physical implementation. But I guess looking at the truth table would really have been all you needed to know without going through the mind gyrations.

[@mmpiforall5913]

It bums me out that CD series CMOS is considered 'old', OK it is, but these handy building blocks along with 7400 series, LM analog circuits, INXX 2NXX and 3NXX parts allows a lot of circuit design in small business, industry and everyone else. If we only had LSI scale ICs to work with, imagine how limited we would be!

[@AnalogDude_]

they are produced and sold freshly today, it's still pretty hi-tech and you need an electron microscope.

[@jp040759]

It's funny how you see this schematic with all 10 resistors. One for each LED. In actuality your really only need one resistor since only one LED is on at a time. Useful chip with some creative thinking.

[@stevenwright901]

Yeah, what’s that about

[@jp040759]

@@stevenwright901 ?????????????????????????????????

[@markharrisllb]

@@jp040759 I think Steve Wright was agreeing with you and asking what all the resistors were about, ie why have them all?

[@mrtom64]

Very good but I'm surprised you casually brushed aside the usefulness of the reset pin.

[@zilog1]

This chip looks useful for a control unit for a cpu design

[@AnalogDude_]

Maybe you should adapt the title and add CD4022 as wel. You forgot to mention that the reset pin resets the device to pin "0" witch is pretty useful and could be overlooked.

[@richardl6751]

This is the chip I used for my little circuits. 6 led scan kzbin.info/www/bejne/paXZmXeBYrl2o8U One way scan kzbin.info/www/bejne/o5DQo6WwppV8adk two way scan kzbin.info/www/bejne/pJjMZZirabCFrdk

[@squidkid2]

So what did I learn. That data sheets sometimes are totally incorrect. Well that's really reassuring for all us newbies who rely on them to be correct. Interesting.

[@IMSAIGuy]

the datasheet is not incorrect. I just point out drawing the schematic a different way to show functionality. If you are designing your own digital circuits this can be valuable.

[@alekseibutyaev2318]

where you bought a led set? or it is yours product

[@IMSAIGuy]

that one I bought on eBay. search 'LED 6bit'

[@alekseibutyaev2318]

@@IMSAIGuy subscribed to your channel for 3 months. there are interesting episodes, for example, by GAL. you should have posted the source code.. the technology is old, but sometimes it's hard to get into grandfather's chest.

[@sammin5764]

🌟🌷🌟

[@byronwatkins2565]

I found most logic rather obvious, but DeMorgan's theorems took some convincing.

[@DiaconescuAlexandru2024]

Circle circle

[@mariobv947]

Hi @IMSAI Guy, Do you remember the e-mail message i sent to you some days back, regarding a resistor ladder, that you never replied and probably never read as such e-mail would be still waiting in the spam folder? If you look over my KZbin channel, you will find a video in which i hacked a 30cents 4017 module from China into a full logarythmic stereo vumeter by using a resistor ladder of the same kind (it uses the same working principle as a special DAC, but using different values because in this circuit, the purpose is to generate a stepped exponetial to be compared with the input signal, hence the logarythmic behaviour of the vumeter).

[@IMSAIGuy]

I did look at the two websites. it was pretty basic, but thanks.

[@mariobv947]

@@IMSAIGuy Yes, it is very basic, but i've never seen such a simple manner of generating semitone voltages (2^(1/12)) for feeding a 1Hz/mV VCO using comercial valued resistors. People making monophonic keyboards or keynote sequencers, have to deal with linear to exponential converters and voltage quantizers to get music notes from their oscillators. Even for people doing 555 keytone boards have to adjunt or trim every single resistor for every keynote. I did it just simple with a linear VCO made of a 555 and a couple of opamps, some SPDT momentary switches, and that resistor ladder, and it fits as a fiddle. I thought this could be of any use for your synth if you want to add a sequencer (made of a CD4520 and some sram like HM6116 or so) that generates voltages that can be matched to semitones this way. Thank you, anyway.

[@shadimurwi7170]

Zamzam water from mecca saudi arabia is tasty

[@andye2005]

The DeMorgan brought back a quote from my early electronic training Break the line change the sign It turned out to be fairly simple. It was never described as the different shapes. Different teaching methods I expect One of the main uses was to enable a circuit to use all the same type of gates Now I will have to look up karnaugh maps again

[@iblesbosuok]

Inhibit = NOT(Enable)