I would like optocoupler . I can’t find it.
An optocoupler (also called an opto-isolator) is an electronic component that transfers electrical signals between two isolated circuits by using light.
- Inside the device, an LED converts the input electrical signal into light.
- A phototransistor (or photodiode/photothyristor, depending on type) receives that light and converts it back into an electrical signal.
- This provides isolation between the input and output sides, protecting sensitive circuits from high voltages or noise.
Currently, the optocoupler component is not available in DCAClab.
However, you can simulate its behavior by combining an LED and a LDR.
Since you have an LDR (Light Dependent Resistor) in DCAClab, you can use it to simulate the output side of an optocoupler.
How to simulate an Optocoupler with LDR in DCAClab
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Input Side (LED)
- Place an LED with a series resistor connected to your input signal (DC or AC depending on your test).
- When the input is ON, the LED emits light.
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Output Side (LDR + resistor or transistor)
- Place an LDR close to the LED (so that when the LED lights up, the LDR’s resistance decreases).
- Connect the LDR in series with a resistor and a DC supply (like a voltage divider).
- You can even connect it to the base of a transistor to simulate the phototransistor behavior.
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Working Principle in simulation
- LED OFF → LDR has high resistance → almost no output.
- LED ON → LDR resistance decreases → current flows → output signal generated.
Example Connection Idea
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Input side:
Vinput → Resistor → LED → GND -
Output side (simple version):
Vcc → LDR → Output Node → Resistor → GND
The voltage at the Output Node will change depending on the LED light → simulating an optocoupler.
This is not a real optocoupler but a functional equivalent using available DCAClab components (LED + LDR). If you want to use a chip version, you can later implement it with IC Creator + NGSpice netlist.