photo detector circuit

[renaissances21]

Hi,

I'm trying to design a photo detector circuit. Can anyone share with me how the circuit will look like? I just want a simple photo detector that when leds shine light on the finger and photo detector detect and give reading of human pulse.

 

[stevez]

A pulse oximeter looks at O2 levels in the blood using a fingertip device that includes LEDs. I think it also provides a pulse rate. You might google on pulse oximetry to get some ideas.

 

[akg]

ok..i have seen some ckts like this.. the skin(or blood?) reflects IR , and the reflected intensity depends upon the blood beneath the skin . so u can build an IR diode + phototrans as the detector and monitor the amplified signal from the phototrans

 

[Nigel Goodwin]

Hi,

I'm trying to design a photo detector circuit. Can anyone share with me how the circuit will look like? I just want a simple photo detector that when leds shine light on the finger and photo detector detect and give reading of human pulse.

Try having a look at **broken link removed** which shows a PIC based one. The actual sensor part looks like this: