How to connect light-emitting diode and photodiode ?

Hello,

I actually work on a rain sensor model and I would like to simulate the electrical circuit, but I have some problems. I search some solutions on the web but I didn't found anything. I only found a question, which I also have :

When I connect light-emitting diode (port W) to photodiode (Port D) in simulink, errors will occur. It says 'Invalid Physical Signal connection at port 'W'. Source unit is 'W' and destination unit is 'W/m^2''' What do I need to insert between light-emitting diode and photodiode?

Thanks!

[betül kalfa]

Hello. I also have the problem you mentioned between Photo diode and LED. Did you find the solution? Can you share it?

Answer 1

[Dallas Perkins]

Hi Alexandre,

Since physical signals have units associated with them you need to get those to line up between your two components. The LED outputs an optical power in W, and the photodiode accepts a radiant flux density in W/m^2. To connect the two you will need a gain to scale by surface area in 1/m^2. A PS Gain can be used to do this.

Best,

Dallas