IR diode and phototransistor

Thread Starter

Eric007

Joined Aug 5, 2011
1,156
Hi Everything Ok with this schematics?
Highlighted part?

Vdd = 5V

Thanks!

Edit: pdf file removed + schematics
 
Last edited:

MaxHeadRoom

Joined Jul 18, 2013
22,343
I might have gone lower with the diode resistor for the opto, they are rated for up to 50ma, yours will be something less than 5ma taking in the voltage drop for the diode.
Max.
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,156
Here are the new changes based on the other 2 attached...

don't have 3k so put 2k2 at comparator output...
Anything missing or ...

Edit: schematics removed
 
Last edited:

John P

Joined Oct 14, 2008
1,872
The 10K resistor (R2) might or might not be right, depending on the amount of light that passes from the LED to the transistor, and that depends on alignment and distance, neither of which have been mentioned. Then you have the issue of ambient light: if this rig must operate in daylight or incandescent illumination and there isn't any shielding of the receiver, you risk having the sensor say "I'm seeing light" all the time. If that's the situation, you'd most likely need to go to a modulated-light setup.
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,156
There's no R2 with value 10K...R2 value is 330

Edit: Schema edited...Check R15

schematics gone!
 
Last edited:

John P

Joined Oct 14, 2008
1,872
R2 in the middle diagram, posted Today, 06:13 AM? I think that's your R10.

R15 in the diagram of Today, 08:12 AM doesn't seem to serve any function. Why have it there at all?
 
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