SN74141N - cannot make it work

I bought several SN74141N chips. I wanted to control nixietubes with them.
The datasheet can be found here

https://pdf1.alldatasheet.com/datasheet-pdf/view/115765/TI/SN74141N.html

Before I connect it to the nixie tube I wanted to check if this would work for normal LEDs. Connected just 5 linked to pins corresponding to outputs 0 1 2 3 4
So I have 5 LEDs where I connected Anodes to 5v
I have conneced the chip to arduino in the following way

D6->A (pin3)
D3->B (pin6)
D2->C (pin7)
D5->D (pin4)

I connected 5V to pin 5 and GND to pin 12

So the way I understand this chip should work is that I send 4 bit binary number and the chip sends GND signal to the pin corresponding to that number

e.g. if I send

D C B A

L L L H that is 0 0 0 1 and corresponds to 1 so the ground should be send to pin 15 and the corresponding LED should be lit.

same for

D C B A
L L H L that is 0 0 1 0 and correspnds to 2 so ground should be send to pin 8 and the corresponding LED should be lit.

I wrote sample code where I tried to lit the LED connected to pin 15 (corresponding to 1)
Unfortunately regardless of the ABCD combination I send to Arduino I get the LED connected to PIN 8.

Are thouse faulty chips or am I doing something fundamentally wrong.
I attach the photos.

#define A 6
#define B 3
#define C 2
#define D 5

void setup() {
   pinMode(A, OUTPUT);
   pinMode(B, OUTPUT);
   pinMode(C, OUTPUT);
   pinMode(D, OUTPUT);
   digitalWrite(A,LOW);
   digitalWrite(B,LOW);
   digitalWrite(C,LOW);
   digitalWrite(D,LOW);
   Serial.begin(9600);
}

void loop() {

   digitalWrite(A,HIGH);
   digitalWrite(B,LOW);
   digitalWrite(C,LOW);
   digitalWrite(D,LOW);
}

How to post an image


As best I can tell your wiring is correct, but the 74141 is not intended for LEDs. Have you read the datasheet? The bit that says:

Low−Level Input Current A Input -1.6mA

You don't have resistors in series with your LEDs, you need them to limit the current to under 1.6mA, I would think you have damaged the chip.
[EDIT] The above is wrong, see replys #6 and #8

I do have resistors. As you can see on the picture I use those lilypad leds that have build in resistors.
I also just noticed that the chip heats up.

Dziubym:
I do have resistors. As you can see on the picture I use those lilypad leds that have build in resistors.

I could not see the resistors, even now you've pointed them out I can't see them :confused:

OK, do they limit the current to below that specified in the data sheet? (I suspect not).

I don't myself use those wires you've got, however, I've seen a lot of questions on here resolved by checking the wires and finding that one or more has a bad connection.

I HATE alldatasheet.com AND ITS COUNTER PARTS !

The -1.6 ma is a nominal TTL input current to register a LOW, one TTL input load.
We must pull current out of a TTL input for it to be a LOW.[Go figure], hence
the minus sign. The input spec has nothing to do with the LED current.

The LED has 330 ohm resistor

I am electronic beginner. I would have thought the current woud not be larger then the current that flows through the nixie tube.

I tried to measure the current just by connecting 5v to led and then to GND. in a 200mA scale it shows 8,02. So is it 8mA. Possible? In that case that would explain why it does not work.

Is it possible to do a dry run with LEDs. I can findthe resistor that will limit the current. The question is is the LED going to lit then?

herbschwarz:
The -1.6 ma is a nominal TTL input current to register a LOW, one TTL input load.
We must pull current out of a TTL input for it to be a LOW.[Go figure], hence
the minus sign. The input spec has nothing to do with the LED current.

++Karma; // For spotting my mistake

I am not not sure what the maximum output current per output is, but this is specified:

Current Into Any Output (Off−State) 2mA

Although I find (off state) confusing, unless they mean low. My point still stands though, too much current.

I am electronic beginner. I would have thought the current would not be larger then the current that flows through the nixie tube.

Nixie tubes have a different characteristic to LEDs. LEDs need current limiting resistors to the current you want.

I tried to measure the current just by connecting 5v to led and then to GND. in a 200mA scale it shows 8,02. So is it 8mA.

You must not connect 5V to an LED without a resistor, you will damage the LED. Lots of discussion on here about LED current limiting resistors, do some searching.

Take your DVM and confirm the output is DCBA 0v 0v 0v 5v

My TI data sheet shows "On-state output voltage = 2.5 Vmax @ Io = 7 ma."

I thought the current flowing through the led would be smaller expecially with current limiting resistor, then the current flowing through Nixie tube (causing glow discharged)

I will try to connect it with nixie tube as intended.
I attach the diagram I intent to use. Not sure how to post the image so it shows in the body of the message

The nixie tube I want to control is IN-1 and I found in the data following information
Typical Cahthode Current mA 2.5

My data sheet states that the 74141 "drives gas filled indicator tubes directly."
Normally we use a (ballast) resistor to limit the current through a neon lamp,
so, please check for that requirement before powering up the Nixie tube.

I cannot really find anything for IN-1 apart from
http://www.tube-tester.com/sites/nixie/dat_arch/IN-1.pdf
with very little information and

with tons of information.

In the diagram I posted there is 20k resistor used. I have seen other connection diagrams where they used smaller resistors. So I hope I will not fry yet another chip and Arduino Nano:)

larryd:
I HATE alldatasheet.com AND ITS COUNTER PARTS !

Yes, there needs to be a way to completely exclude them from Google searches. :roll_eyes:

Particularly when they generate - as they do - spurious results. :astonished:

"I HATE alldatasheet.com AND ITS COUNTER PARTS !"

Gotta stop using old obsolete parts :sunglasses:

CrossRoads:
“I HATE alldatasheet.com AND ITS COUNTER PARTS !”

Gotta stop using old obsolete parts :sunglasses:

But they have so much character :(.

larryd:
I HATE alldatasheet.com AND ITS COUNTER PARTS !

I thought it was only me that hated it...

larryd:
I HATE alldatasheet.com AND ITS COUNTER PARTS !

You guys must be using it wrong.
Its my prime place for all semiconductors, including industrial stuff.
Do you read the results of a search and use your brain to decide on what to look at?
Tom... :slight_smile: