Breakbeam Sensor Help

Basically I need one generic led to turn on when an object passes though the senor shown on the following link

search.digikey.com/us/en/product … ND/1015177

I figure its pretty simple to do just need direction on how to wire it up.

Hello, NewbieTechie.

Do you already know how to get an LED to turn on in general, without involving a sensor?

–David

yes

I don’t have any experience with that sensor, but I can at least point you to resources that you might find helpful.

According to the datasheet, that sensor has an LED and a phototransistor.

It looks like you need to use the red and black wires to power the LED, and you probably need an appropriate current-limiting resistor.

For the phototransistor you might be able to make a circuit like the one in this article (but I’m not sure if it’s good):

evilmadscientist.com/article.php/nightlight

I found this by searching Google for “connect phototransistor to led”.

–David

Ok Ive figured out how the red wire and black wire are 5v power in and ground respectively. What i need help with is the emitter and collector wires. How would they be resisted and how are they connected to an led?

You might be able to connect the phototransistor to an LED if you make a circuit like the one in this article (but I’m not sure if it’s good):

evilmadscientist.com/article.php/nightlight

I found this by searching Google for “connect phototransistor to led”.

–David

Yeah that didn’t seem to be what we are needing it to do David. This is what me and my constituents have came up with so far.

guru.com/upload//MessageAtta … 8/opto.jpg

We’ve wired it up to this schematic but when powered we get no response from the break-beam. I’ve checked continuity and its has resistance so we figure its not the sensor. Right?

I don’t know the answer to your question.

Is your LED on or off? You chose a very high value for R2; did you make sure that R2 is strong enough to pull the voltage up to to 5 V or so when the light is blocked? You can use a multimeter to debug these things. I would disconnect the inverter and just use a multimeter to measure the voltage on pin 4 until you can get the sensor working.

–David