# Need help finding IR sensor

#### Kosakoskim

Joined Dec 16, 2009
5
I would like help finding the correct IR sensor for my project. I am creating a pneumatic can crusher that is controlled by a solenoid operated valve. I am going to have to modes the can crusher can be in, auto, or manual. When in auto mode before the solenoid operated the cylinder a IR sensor will need to be triped by a can sliding down into the chamber. I already have a couple time delay relays to use, I just need to find a sensor that will work. I will need it to supply a 24VDC signal when it is triggered, and go away when the can is past it. It will be mounted to sense movement through a small hole in 3" exhaust tubing. So i am not aware of all the different types of sensors but i think i would either need one that shoots a beam to another sensor and when broken it activated or a sensor that detects motion. Thank you for your time and ideas!!

#### Papabravo

Joined Feb 24, 2006
13,470
A simple ON/OFF IR sensor can be triggered by numerous types of extraneous sources. In remote controls for entertainment devics, a data signal moulates a carrier signal in the range of 30-50 kHz., with 38 kHz. being a typical value. This way the sensor can have a filter that rejects signals that are not modulated at the correct frequency.

Checkout for example the TSOP1738 from Vishay.
http://jap.hu/electronic/tsop17.pdf

Generating a 38kHz. carrier into an IR-LED is just about the easiest thing you can imagine.

#### BMorse

Joined Sep 26, 2009
2,675
No for this type of application, I would not rely on some home made sensor, I would use a Photo-Reflective type sensor that uses a prismatic reflector on the opposite side, there are a variety of distributors online and at your local electrical store (here in Michigan we have a store called Standard Electric, they supply to contractors and such), these sensors can be PNP or NPN output, you have to specify which one you need, also, they have output on when light is present and output on when light is blocked, some can be wired for either one, so do some homework and figure out which one suits your needs better, they usually operate on voltages that range from 10 to 30 VDC. Some are AC also, but the load has to be tied directly to sensor....

There are several manufacturers for these type of sensors:

• Baluff
• IDEC Corporation
• Telemecanique

#### Papabravo

Joined Feb 24, 2006
13,470
Those industrial components will tend to be pricey, but if it is somebody elses nickel, cost may be a don't care. I thought you wanted to build one cheaply from simple components.

#### Kosakoskim

Joined Dec 16, 2009
5
The sensors range from 15-30 dollars, I dont have a problem spending that much its just finding the one that will work.

#### Dalaran

Joined Dec 3, 2009
168
Check out Mark III Robotics Store:
http://www.junun.org/MarkIII/Store.jsp

They have proximity and distance IR sensors for under $10. Shipping almost took 3 weeks but most likely because I am in Canada. #### BMorse Joined Sep 26, 2009 2,675 Check out Mark III Robotics Store: http://www.junun.org/MarkIII/Store.jsp They have proximity and distance IR sensors for under$10. Shipping almost took 3 weeks but most likely because I am in Canada.

Those sensors will not work for his application, he just needs an on off type output, not a variable voltage depending on distance of object. He does not need to know how far the object is, just that it is in view. And also using a IR detector emitter pair ins a retro-reflective setup will not work, since the coloring of the item can give false signals, the op needs a thru beam sensor with ir detector on opposite side of IR transmitter to properly detect any objects in between.

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#### BMorse

Joined Sep 26, 2009
2,675
here are a couple of quick and easy circuits for using a IR LED and a phototransistor (Radio Shack sells a pair in a package) to detect objects....

#### Kosakoskim

Joined Dec 16, 2009
5
I am very new to this would you car explaining how the circuit works and what else i need besides the LED and phototransistor detector. and i need to make it high output on detection and be 24vdc

#### Duane P Wetick

Joined Apr 23, 2009
426
Check out www.Bannerengineering.com site. They manufacture all types of photosensors in small packages and have lots of applications information. Have used their stuff for years in recycling applications.

Cheers, DPW [ There is no computerized explorer in the world with even a tiny fraction of the power contained in the chemical analog computer known as the human brain whose reproduction is easily accomplished by un-skilled labor.]

#### Wendy

Joined Mar 24, 2008
22,138
I'm surprised no one mentioned this, but...

DON'T FORGET AN EMERGENCY OFF SWITCH!

I think the reasoning is obvious.

#### BMorse

Joined Sep 26, 2009
2,675
The proximity sensor at Mark III Robotics gives a high output when the object is within range and a low when it is not.
http://www.junun.org/MarkIII/Info.jsp?item=24

[SIZE=-1] The GP2D15 has a pre-set distance threshold of 24cm.[/SIZE]

I do not think he is going to have the sensor that far outside the machine for crushing the cans...... I am sure the area he is trying to detect the item in is no more than a few inches wide, maybe a foot at the most.