I still think pin 5 requires a DC path to ground for proper operation. I duplicated the circuit you posted and with pin5 not connected or floating I have the #10 LED always on. Connecting a 1meg resistor from pin5 to ground fixed that problem.

Hi and thanks for your contribution I appreciate but I tried to put a 1M Ohm between PIN 5 and the Ground and the signal Cutout.

You have the #10 LED on but me this #1LED.

See the dropbox link enclosed below:

https://www.dropbox.com/s/fulqkn3savd6ib7/IMG_0049.MOV?dl=0



I don't understand

 

I still think pin 5 requires a DC path to ground for proper operation. I duplicated the circuit you posted and with pin5 not connected or floating I have the #10 LED always on. Connecting a 1meg resistor from pin5 to ground fixed that problem.

I agree, the input signal should not be left floating.

 

Hi and thanks for your contribution I appreciate but I tried to put a 1M Ohm between PIN 5 and the Ground and the signal Cutout.

Its supposed to do that...

 

Its supposed to do that...

Sure I trust on you..I don't understand !!!!!

 

Sure I trust on you..I don't understand !!!!!

Apply 125m VDC or greater to pin 5 with the 1meg resistor connected from pin 5 to ground. The LED should turn on.

 

Hi and thanks for your contribution I appreciate but I tried to put a 1M Ohm between PIN 5 and the Ground and the signal Cutout.

Must be doing something wrong! We still need to see how the input pin5 is connected to the audio signal.

 

Must be doing something wrong! We still need to see how the input pin5 is connected to the audio signal.

Hi all

I made many tests tonight and I confirm you this the BARLED bloc, I tested with another Bloc and I don't have the problem.

I don't what's Up with this bloc but I am sure now.

Many thanks all for your help and very sorry about the trouble.

Best and Happy new year

 

Hi all,

After many tests I found a solution, put a resistor in parallel with the LED 1 , in my case and versus my 10 LED BLOC the value is 15K, this value is different following the 10 LED BLOC you use.

This value attenuate a very little bit the brightness, but this is very negligible.

I don't know why this problem is only on the LED 1.

I would want to tell thanks for your help and patience.

 

I don't know why this problem is only on the LED 1.

Probably because the comparator reference voltage for LED1 is so low (only 125mV) that your signal source isn't pulling its voltage down below that, or else because noise on the signal line or ground line exceeds that reference level.

 

Hi all,

After many tests I found a solution, put a resistor in parallel with the LED 1 , in my case and versus my 10 LED BLOC the value is 15K, this value is different following the 10 LED BLOC you use.

This value attenuate a very little bit the brightness, but this is very negligible.

I don't know why this problem is only on the LED 1.

I would want to tell thanks for your help and patience.

Glad you solved the problem.
Can you provide the part number for the LED bargraph your using?

 

Glad you solved the problem.
Can you provide the part number for the LED bargraph your using?

Oh this a AliExpress (LoCNService) saler, I am not a very afitionados of Aliexpress but it was the only saler who have the 10LED BAR bloc I need (5Green/3Yellow/2Red).

 

Probably because the comparator reference voltage for LED1 is so low (only 125mV) that your signal source isn't pulling its voltage down below that, or else because noise on the signal line or ground line exceeds that reference level.

Thanks for your reply but I don't have this problem with another BARLED Bloc it's strange, I think there is a build problem with this Bloc.

 

The datasheets for the LM3914 and LM3915 say that a tiny current flows in the 1st LED at any input level so that two or more ICs can be connected cascaded in series. Then a resistor parallel to the 1st LED turns it off when not lighted.
On My LM3915 Sound Level Indicator circuit I used a 22k resistor 16 years ago.

 

On My LM3915 Sound Level Indicator circuit I used a 22k resistor 16 years ago.

I have verified the same. Using a 22K resistor fixed the issue as well. From my setup I measured .065ma through LED1 when OFF which apparently is enough if the LEDs used are super bright type. Using a "standard" LED no problem.
I suspect that the BARLED Bloc the TS is using is not the same as the one he has no problem with.

 

I have verified the same. Using a 22K resistor fixed the issue as well. From my setup I measured .5ma through LED1 when OFF which is enough if the LEDs used are super bright type.
I suspect that the BARLED Bloc the TS is using is not the same as the one he has no problem with.