Hello , I have built a current protection system that shuts down the current and lights blue LED in case some thing problematic happens.
component datasheet is atached.
In the simulation I used some spice model for BLUE LED which I found in google ,its is not the formal model of the component,that consumes 14mA and 3.6V.
But in reality I see much that it consumes 20mA when functioning.
I am afraid it my diode will not open up un like simulation.
Is my LED will open in real life as in the simulation?
Ltspice files are attached.
https://www.digikey.co.uk/en/products/detail/cree-led/C503B-BAN-CX0B0461/4793631

 

The schematic is missing important information: Power source for the circuit, a connection to the D3 cathode, etc. Also, most of the U10 pin assignments are incorrect.

BTW, many people on this forum, including me, will not open ZIP or other archive files.

ak

 

The circuit doesn't make sense with the pin numbers listed in your schematic as ak just mentioned.
What does the negative side of LED3 connect to?
Pins 1 and 2 are open collector outputs not inputs.
Also need to stop referring to "will my LED open up".
Use terms like: will my LED light up, turn ON, activated, illuminate, please.

 

But in reality I see much that it consumes 20mA when functioning.
I am afraid it my diode will not open up un like simulation.
Is my LED will open in real life as in the simulation?
Ltspice files are attached.

I have no idea what you are trying to say here. What does it mean for an LED to “open up?”

 

if such LED is connected to 5V with series resistor of 500 Ohm, then current is expected to be about 2.8mA.

 

I have no idea what you are trying to say here. What does it mean for an LED to “open up?”

It means that in the simulation I see a good behavior an 18mA consumption but I am not sure in reallife my LED diode will light up as in the simulation.

 

my LED diode will light up

Light up is OK.
Thankyou.

 

A RED LED will start to glow at a Much lower voltage and current than what it is specified for. Other colors, and white, as well. BUT the specified light output happens at, and around, the specified current.
AND A FUNNY THING that I discovered is that some LEDs will get brighter and draw more current when externally illuminated.
Also, some LEDs will produce a DC output when illuminated. Some much more than others.

 

I was told the following advice:
"Comparator load resistance of 500 ohm is too low at least for LM339. LM339 is possibly in current limit, not able to pull output fully low. I'd double RL to 1k for all comparators. R21 may need to be adjusted respectively"

I dont understand what is the meaning of this limitation. few questions:
1.How exactly this optocoupler diode limits ?
2.is it a limitation that what allow to open the LED diodes?why?
3.Why puulup resistor of the comparator desides the current threw the diode?
Thanks.

 

I dont understand what is the meaning of this limitation. few questions:

First, need to post a correct schematic. The schematic shown in post #1 is garbage!
What optocoupler diode are you speaking of?
Again, STOP using the term "open the LED diode". Use one of these terms please, Turn ON, Light UP, Illuminate or Activate.

 

 

Still a disaster.
The pin numbers on the LM311 and LM339 shown on this schematic are all wrong.
The LM339 contains four individual comparators, so why the LM311.
What value is Main V?

 

LTspice simulation file is attached.


The main advice I was told regarding a problem in the attached circuit described in the photos and zip simulation files is the pullup resistor needs to create output strong enough to open the diode and the optocoupler isolation diode.
What is the mathematcal link behind pullup resistor value of each comparator and the current the comparator produces?
How can I know that my pullup resistor is not high enough given the simulation.

 

Did you design that circuit?

 

How can I know that my pullup resistor is not high enough given the simulation.

The another problem is not speaking in the correct terms as applied to this circuit.
What is the value of Vpp?
I don't do LTspice.

 

50 % me 50% google.
12V is the value , you can see it in the LTspice simulation I shared.

 

As I stated , I don't use simulation software.
I see where you are trying to go with this circuit but until you get the pin numbers correct and list supply voltages it's impossible to further advise.

 

First of all, the blocks tagged as LM311 and LM339 look like blocks depicting an opto-isolator.
Next, an LM339 dual comparator has an NPN OPEN COLLECTOR output which does limit the current to 5 milliamps, I think.
THIRD, an opto-isolator with an LED input and a photo-transistor output must have the LED current limited to avoid destruction, AND a series resistance of some kind to limit the collector current of the output transistor.
SO WHAT I SEE is that google is suffering from a case of severe A.I. hallucinations. That is the most polite explanation.

 

Hello MisterBill2,Very good advices.
Could you please reccomend a current limiter of 50mA so I wont burn the isolation diode of the optocoupler when all three protections will be ON and exceed the datasheet 60mA maximum?
if it has Ltspice model it will be great.

 

OK, I see 5 volts at one place in the drawing, and 12 volts mentioned here. The abs max current, above that is assured destruction, is 60 mA. For TEN milliamps , 1200 ohms is reasonable. For a bit over 20 milliamps a 560 ohm (Green, Blue, Brown is a correct choice.
I DO NOT recommend operating towards the ABS MAX values.