optical interrupter switches

[arbus]

Hi,
Just wondering if there is a circuit diagram for wiring up optical interrupter switches? Switches i am using are these http://www.jaycar.com.au/products_uploaded/ZD1901.pdf

I am using a 5 volt power supply and a 100 ohm resistor on the Diode side with a pull up resistor between the collector and the battery. Just cant make it work

Thanks,
Ar

[vger]

Change your limit resistor to 330 ohms. The pull-up will depend on what you are driving with it. If it's TTL, use a 4.7 K pull-up, for CMOS try a 10 K, FET go with 39 K.

After changing to the 330 ohm pullup, check the diode current (you can look at the voltage across the pullup) should be about 15 ma.

Steve

[Al_The_Man]

Make sure you have the diode forward biased, also they do not show clearly the transistor type, NPN/PNP? The fact they show 30v collector emitter voltage, I am assuming it is NPN?
Al.

[AlainB]

Hi,

Here is a link about what you are looking for. I tried it. With the part I used, the LED is ON when the slot is NOT interrupted.

Alain

http://www.fignoggle.com/workshop/ar...-wiring-how-to

[Greolt]

AR

Here is a quick sketch made from the PDF you posted.

Use the pull down as recommended by Steve

Greg

[Al_The_Man]

Originally Posted by Greolt AR Here is a quick sketch made from the PDF you posted. Use the pull down as recommended by Steve Greg

But then as opposed to Alains post you show an emitter follower, where there should be a load resistor from emitter to common.
Al.

[Greolt]

OK obviously I bow to your electronics knowledge here.

I just know that is how I hooked mine up and they are working.

If this is wrong I had better do some more reading.

Hopefully I am not stressing some component by overloading.

Greg

[Al_The_Man]

Originally Posted by Greolt If this is wrong I had better do some more reading. Greg

Not that it is wrong, just that you missed out the emitter connection, the way you have it drawn there would be a resistor from emitter to common, unless the receiving device has a pull down (sink) resistance.
Al.

[arbus]

Thanks Heaps!
I have got it set up as in Alain's Diagram, using 270 Ohm Resistor (its all i had)
and its switching the Led on and off nicely.
My next question is that i need to hook it up to a parallel port. To do this i need to pull it down to under .8V? (Active Low)? At the monent it is still at 1.4V When Interrupted (measuring across the LED)
So is this correct ?

[Al_The_Man]

Its not the LED that is the output, it is the transistor, referring to Alains print, your output would be the emitter to common, this is the level you should measure.
Al.

[AlainB]

As I found out, you can use the "switch" side as a normal switch (more or less!). Power up the LED side, put some voltage on one side of the switch and a volt meter on the other side and ground and you will read your voltage or 0 volts whenever you interrupt or not the slot. If it is not working, just invert the switch wires. The switch is polarised. Block the slot with a piece of metal. With cardboard or paper you will not reach 0 volts.

My 0,02$ (CAD), with the parts I used!

Alain

[arbus]

It works!!!

Thank you very much, It took me about an hour to get it to work, until i read Alain's post

"If it is not working, just invert the switch wires. The switch is polarised."

Ar