Photo transistor biasing

[NARENDRA1234]

I am using this pair of photo transistor and photo diode..i am confused about biading ckt of photo transistor..light emmited by LED wii pass through turbid solution and change in the intensity is detected by photo transistor..this is how it should work ..please help mee..

 

[kspalla]

Check the picture Ic Vs Vce for a given irradiance of your application.
keep the same for the bias

 

[NARENDRA1234]

ok i will see it thnks man

 

[NARENDRA1234]

Check the picture Ic Vs Vce for a given irradiance of your application.
keep the same for the bias

how to measure irradiance for our phototransistor?

 

[Gagandeep sharma]

It is ever given in the data sheet.

 

[franciscorc]

Hil All
The photo trasistor is a infrared Type(receiver).To maximaze sensitivity you should use an infrared diode instead of a white led.
Take a look in the figures for the white led(pag 6) and the photo transistor(pag3) you will see the peak emmission is at about 460nm for the white led but the peak sensitivity for the photo transistor is at 960nm.

Best

Francisco