The current in each half of the circuit is linked by the Current Transfer Ratio or CTR, which is simply the ratio of output current to the input current (I C /I F) usually expressed as a percentage. Each optocoupler type will have a range of CTR values set out in the manufacturer's. In choosing appropriate values for R1, the value for the current limiting resistor is set to produce the correct forward current (I F) through the infrared LED in the optocoupler. The CTR has the following characteristics and is therefore as important as the. An optocoupler, also known as photocoupler or opto-isolator, is a device which can transfer an electrical signal across two galvanically-isolated circuits by way of optical coupling. I can't understand if the CTR is or isn't a critical value and for what applications is it used in. It's poorly controlled and you. A: The input of optocouplers is defined with the forward current IF of the emitting diode and the reverse voltage which should not be exceeded. Figure 6 gives a detailed overview for the binning groups available, providing their minimum to maximum CTR range within.
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