Sensor without datasheet, what can I do??

kubeek

Joined Sep 20, 2005
5,794
Could be optical barrier sensor, led+phototransistor. But also it could be anything else, where did it come from?
 

mcgyvr

Joined Oct 15, 2009
5,394
If you know what it does you should have included that bit-o-knowledge in your post so you didn't get replies guessing a black sensors function.
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
This sensor contain the led and the diod sensor. when you block the light from the led the diod should stop giving '1'. probebly.
 

KMoffett

Joined Dec 19, 2007
2,918
Because there "6" pins in the bottom view, my guess is that it's a quadrature detector. One LED, and two phototransistors or photodiodes. It would have been associated with a slotted/barred wheel, or a barred strip.

Ken
 

Thread Starter

JK-FlipFlop

Joined Jul 5, 2010
111
I have expectations from you to give me any idea of how I can check it or try it.
I have tools to check it but I don't know how...
 

KMoffett

Joined Dec 19, 2007
2,918
Here is how I see the circuit on the PCB. I'm assuming the one part of A1(a), because of it's relative position, is an LED. I'm making an assumption on the polarity. This can be verified with the diode range on a DVM. The other parts of A1 (b & c) are likely photo transistors. Measure the resistance of R1. You would need to power the LED/R1 circuit 3&1 and add load resistors between 2&3 and 1&4. Block and unblock the optical path and see what happens at to the voltage 2&4.
This is just speculation.
Ken
 

Attachments

Interesting.

In the top view with the connector, let's call the top of the four conductors on the ribbon cable "1" and number down from there.

I'm guessing pin 1 is ground because it leads to a large pour of copper.

I'm guessing pin 3 is the Vdd for and LED, because it goes to one side of a 2-lead device and the other side has a resistor, I assume it's a current limiting resistor.

From that, I would put some voltages across pins 1 and 3, starting low like 2V and going higher until you see current flow. If it doesn't work, reverse the polarity. It may be backward from how I think. I'd sense the current going through, with another resistor in series. That way, you may see that it's drawing current, and you may tell from the current profile it's an LED. If it's infrared, you won't see it unless you have an infrared camera. but anyway...

I'm guessing pins 2 and 4 are sensor outputs that may vary somehow in voltage, based on whether there's something in the slot. You'll have to track those with a multimeter or scope and see how they change when you play with it.

edit: Yeah, just like KMoffett answered, with a schematic to boot, while I was writing mine.

Hope that helps.
 
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