hi,
This is without the Common Arrow symbol, which is not Ground, the closed triangle is the ground reference.

E

 

hi haman,
Try moving the 10k to the Collector of the Opto.
E
View attachment 352693

I have tried this before and to make sure I tried it again right now it still the same thing

 

hi,
This is without the Common Arrow symbol, which is not Ground, the closed triangle is the ground reference.

E
View attachment 352694

And this what I must get, and this the reference I have designed the circuit on.
but this is not the real case unfortunately

 

If you reduce the PWM frequency to below 1 Hz, does it work with the DMM across the output resistor?

 

And this what I must get, and this the reference I have designed the circuit on.
but this is not the real case unfortunately

If you reduce the PWM frequency to below 1 Hz, does it work with the DMM across the output resistor?

I didn't try that but as you mentioned it, I have tried the following on other bord:
by using two separated supplies the first on the input and the other on the output I get it to work well the output activate when the input is connected (its work just fine) but again that's not the case in the desired circuit.

 

If you reduce the PWM frequency to below 1 Hz, does it work with the DMM across the output resistor?

so I tried a 0.3hz but still nothing on scope nether the DMM.

 

hi haman,
Read this clip;
https://www.google.com/search?q=doe...HyBDCBwkwLjE0LjEyLjHIB0w&sclient=gws-wiz-serp


E

 

Forget the oscilloscope because you have a grounding issue.
A handheld DVM is a true differential volt meter. It will indicate the voltage difference across any resistor.
Even a lowly analog voltmeter would tell you if the voltage is switching between two states, if the frequency is sufficiently low.

I am referring to real circuit operation, not a simulation.

 

Sounds almost like a defective opto where the emitter is not connected to its pin but is connected to the cathode pin.

Have you checked the board for errors?

 

Sounds almost like a defective opto where the emitter is not connected to its pin but is connected to the cathode pin.

Have you checked the board for errors?

yes ,and I have tried other optos but still the same even changed to h11l1 but still the same

 

Forget the oscilloscope because you have a grounding issue.
A handheld DVM is a true differential volt meter. It will indicate the voltage difference across any resistor.
Even a lowly analog voltmeter would tell you if the voltage is switching between two states, if the frequency is sufficiently low.

I am referring to real circuit operation, not a simulation.

I did try on 0.3 Hz and try to measure using voltmeter but it gives zero voltage not even 20mV its just zero, i may have
bother you with that but it measures when connecting the two grounds together.

 

I did try on 0.3 Hz and try to measure using voltmeter but it gives zero voltage not even 20mV its just zero, i may have
bother you with that but it measures when connecting the two grounds together.

Then there is something that is not revealed in the schematic that you have shown us.

 

Then there is something that is not revealed in the schematic that you have shown us.

unfortunately, this is all I have, this is the problem, and I hope to find a solution

 

hi haman,
Any chance you could post a photo showing the wiring and layout of the project?

E

 

Using a voltmeter, measure the voltage across B1, then R8, then opto receiver for PWM at DC on and off.

 

Using a voltmeter, measure the voltage across B1, then R8, then opto receiver for PWM at DC on and off.

Vb1=12V
Br8=0V
Vce=12V

 

Hello,

The h11l1 has a logic gate as output.
The gate needs 5 volts for operating.

Bertus

 

hi haman,
Any chance you could post a photo showing the wiring and layout of the project?

E

my setup is so messy but there is a photo for the opto I don't know if this is clear but it's that

 

Hello,

The h11l1 has a logic gate as output.
The gate needs 5 volts for operating.

Bertus

I know that but it was a try to solve the problem, but it didn't

 

The optocoupler shown has 4 pins. H11L1 has 6 pins.

https://www.mouser.com/datasheet/2/149/H11L1M-1010369.pdf