Thanks for your answer, I am new to electronics and these answers help me a lot.Optocouplers or other isolation means is required if you want to isolate driver from power circuit. With common ground as shown in your schematic, it serves no purpose.
6N136 can work for medium speed inverter, but in your schematic, LED drive current is a bit too low if we look at gauranteed current transfer ratio. Also asymmetrical delay causes potentially overlapping gate drive and shoot through. You'd better shift the inverter to the OC output, this would also save one OC per half bridge. Or generate separated Hi and Lo control signals with intentional dead time.
Hi, thanks for your response.Those opto's you mention are not " fast" in the conventional sense - read the data sheet carefully
fast would be 200nS rise and fall times on the output ...
Rather simple: You did use a different circuit with different part values.What am I doing wrong?
I'm sorry but I'm starting in electronics and this is my first serious project. I still have many things to learn.You did use a different circuit with different part values.
This is the datasheet I'm using and it doesn't specify any load resistor value or at least I couldn't find it.Hi,
This question implements that you read the datasheet and use the exact same circuit and values?
Just to be clear: You want to validate "swtiching times" thus you have to refer to the datasheet schematics "switching times".
What datasheet exactly do you use? Give a link to it. (manufacturer site)
Klaus
Yes, in the circuit there is a RL of 2.2K, close to 1.9KHi,
Where do you have the "0.8us" value from (post#5)?
Isn´t in the same row a column called "Test conditions"? I see: "IF = 16 mA, VCC = 5 V, RL = 1.9 k Ω"
Klaus
Hello, thanks for your reply.Hi,
Maybe I´m a bit dumb.
* Why did you connect "B" with 10k? Where is this shown in the datsheet?
* did you set IF = 16mA? I can´t see this.
* did you drive with R_source = 50 Ohms? I can´t see this.
* did you measure it at a threshold of 1.5V?
If you don´t follow the datasheet you can´t compare the results. I can´t do this for you.
I don´t want to read the whole datasheet for you and write the contents in this thread.
I don´t see how you come to the rise and fall times you mention in post#5. In the simulation? In a true circuit?
Klaus
Thanks,R2 = 1Meg, R3 = 680 ohm, put 150pF and 22 ohm ( in series ) across R1.
Opto coupler circuit design needs to take account of type variations, temperature dependence and aging. Deviating from manufacturer application circuit based on empirical measurements with a single exemplar (or a Youtube video claiming these results) is bad engineering.I used a 10k resistor on pin 7 because there is a floating point there. Many data sheets do not mention it but I saw a video where it was recommended and the improvement is brutal.
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