[drip sensor] which photodiode with an infrared LED ?

[drip sensor] how to identify a photodiode ?

Everybody Hi,

I have to make the following drip sensor (see attached file), the caracteristics of the sensor Assembly (infrard LED+ photodiode) used in the file aren't unfortunately mentionned and recently I got a senor assembly (an MLED930 and a photodiode that were in use together in another drip sensor (analog one), my problem is that a part of name of the photodiode was erased,the only thing I know about it is that it began with BP (it has this shape : **broken link removed**) . thus, so I'm not able to adapt it to the schematic (page 2/fig.3 of the second attached file).

what should I do, how to test it in order to identify it (resistances to use ,polarization ) ?

Any help will be will be hugely appreciated .

@Moderator : could you please change the title of the topic to "[drip sensor] how to identify a photodiode ?", thanks.

Hi,

any suggestion ?

Well it's a diode so you should be able to use a multi-meter in diode test mode to determine the anode/cathode. Not sure hot to determine what resistor you should use.

Hi Sceadwian,

Sceadwian said:

Well it's a diode so you should be able to use a multi-meter in diode test mode to determine the anode/cathode. Not sure how to determine what resistor you should use.

Click to expand...

thank you, you're right for the cathode/anode fixing. another thing, the photodiode used in the attached file is reverse polarized while I don't know whether my photodiode should be polarized that way or not.

It should go in the same direction as the one from the existing circuit.

I think so.