Vudobei Jan 22, 9. Your name or email address: Jan 24, Ok, looking the figure dahasheet, at 15mA there is about 1. Go for a LED current equal to 15mA. You have got how to calculate the LED series resistor correct. Posted by shetsachin in forum: This will give you the LED voltage drop for a given current.
|Published (Last):||28 June 2009|
|PDF File Size:||20.60 Mb|
|ePub File Size:||3.50 Mb|
|Price:||Free* [*Free Regsitration Required]|
But use a emitter resistor in the range of 4. And the higher current. Jan 22, 6. You can use figure 2. As regards the resistance of the transistor, which logic do i use? Find the voltage drop at 15 mA and take this into your calculations please. I will use a trimmer instead a resistor. This will show the voltage drop versus current. Have you done any calculations on LEDs and transistors before? So the current in a 4. Hence the emitter resistor will control the current. Go for a LED current equal to 15mA.
Keep your kids engaged and get them excited about electrical engineering with these fantastic sites. Jan 22, 4. But the transistor in the opto will be more or less full on with a LED current of 15mA.
By using a 4. The output to the Arduino input port will be at the point named Channel II. It is much the same The input is a LED and the output is a transistor. So stick with figure 2 in the datasheet. Jan 22, 7. Do you already have an account? If you feel for it use two resistors in series to get close to the value. And you will no problem at all. Jan 23, No, create an account now. May 11, 5, 1, The higher Vce voltage drop. If the opto is connected to some 5 volt logic gate or controller.
The LED will also have a voltage drop. From the datasheet at page two. Jan 22, 3. And that is also important. Optocoupler fails after month. The voltage drop in the transistor will be typical. TOP Related Articles.
CNY74-2 TEMIC Semiconductors, CNY74-2 Datasheet
CNY74-2 DATASHEET PDF