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In stock 1,341 in stock
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0.40 100+ units

Description: This is an opto-isolator for controlling large loads of current on a single channel. This 4-pin dip can be used in conjunction with relays, small motors, etc. to allow a simple microcontroller to turn on and off up to 50mA.


Comments 10 comments

  • Careful!! The sample schematic shows a 50 ohm resistor in series with the LED. This is WAY too little for an Arduino I/O. 220 ohms or more would be OK.
    The specsheet shows the 50 ohms for testing speed with a signal generator, it’s NOT for general application.

  • Does it matter that your schematic differs from the datasheet? I always thought that the emitter of an NPN transistor always was connected to ground. Like in the datahseet, this would give an inverted output to the input signal. Since this device does not have an external base to drive, will it work (or has it been tested) with the schematic posted with this part?
    Thanks in advance.

  • Can this be used to read a high voltage/noisy signal into the MCU? For instance, Pin 1 is the noisy high voltage signal, Pin 2 ground. Pin3 3.3v from MCU and Pin 4 is digital read pin on the MCU.


  • is there a specific reason why the data sheet shows only a single NPN transistor in this product? why is the datasheet showing a different IC? is the example schematic what I should rely on?

  • Can this be used to read large loads, for example I’m currently using 120v relays to read when a switch is on by an arduino.

  • Could this be used to convert 24V AC to 5V DC?

    • Technically, yes - IF you put it it a circuit designed for such a purpose. This component by itself will not do the job, but it will isolate one circuit from another with each side potentially operating at different Vcc values. I would recommend using a diode and capacitor on the AC side to rectify things to a somewhat choppy DC voltage which could then be fed to the LED side of this part. You would still need an independent 5v supply on the transistor side to detect changes in the AC input (actually, that’s exactly how I’m currently thinking of using this part).

    • No, sorry this used to control higher mA loads not convert voltages.

  • good pricing for such a product, but when will it be back in stock? also does anyone know of an equivalent SMT version of this?

  • I used this in a very simple circuit to control a dSLR camera via wired remote. (@sparkplug781, I think it did match their exaple schematic.) The project was to generate a slow-motion video of a camera’s shutter action.

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