Which is the minimum resistor for an optocoupler?
That optocoupler you are using can have 60 mA forward current in the LED, so give it 5 to 10 mA, not 1 mA. 1 mA is also the minimum from the datasheet, and I like to stay away from minimums like that. The value of the pull-up resistor is uncritical.
How to calculate the CTR of a resistor?
According to the data sheet with If=1mA minimum CTR is 34%. Using series resistor of 1.5k at 3.3V gives If= (3.3-1.2) / 1.5k = 1.4mA. The collector is connected to a 30k pull up resistor.
How to calculate the resistor value for an opto isolator circuit?
I’m looking for help and unfortunately stuck for time on a project, so hoping someone wouldn’t mind helping me out. I am trying to calculate the resistor value required for an opto-isolator circuit.
Can you recommend a resistor value for LEDs?
Can someone recommend a resistor value, thank you very much. I have used the calculator available here: http://led.linear1.org/1led.wiz with a 24V supply, 1.5 forward voltage and 60mA forward current. For 60mA and typical VF= 1.25v
What is the forward current of an optocoupler?
It consists of collector-emitter voltage (VCE) and collector current (IC) as a function of the base current (IB). With optocouplers, the emitter forward current (IF) is approximately equivalent to the transistor’s base current (IB) and is plotted as forward current (I F) in various steps.
Which is 110 °C rated optocoupler phototransistor detector?
The 110 °C rated VO617A feature a high current transfer ratio, low coupling capacitance and high isolation voltage. These couplers have a GaAs infrared diode emitter, which is optically coupled to a silicon planar phototransistor detector, and is incorporated in a plastic DIP-4 package.
How to calculate the resistance of a conductor?
Use the following to calculate the resistance of a conductor. This calculator assumes the conductor is round. An electronic color code is a code that is used to specify the ratings of certain electrical components, such as the resistance in Ohms of a resistor.
What are the CTR values of an optocoupler?
Each optocoupler type will have a range of CTR values set out in the manufacturer’s datasheet.
What kind of current does an opto coupler need?
As the current available from typical computer input/output ports may only be a few µA, as computer port lines are usually designed to drive some type of logic input, the input to this motor drive circuit is via a HCT Schmitt inverter gate, which only requires an input current of 1µA, with the 12V 40mA motor being driven by a 2N3904 transistor.