photogate

Thanks for reading my article in The Physics Teacher about how to build your own photogate for less than $50. Here, I will answer questions about the project, post pictures requested by those who are building a photogate, and put links to other photogates that I have designed. Sorry, I cannot send you a copy, AAPT owns the copyright now. You can order copies from their website, however. Because the circuit used in this device is no longer available, some alternates are suggested at the end of this page. The $10 photogate described below does not use this circuit.

To ask a question or make a comment, just click on the discussion tab above. You may have to register first, but you are only registering with me and you will not receive any email as a result.

In 2010, another article will appear in The Physics Teacher with a $10 photogate connected to the audio port on a computer.

Here is a **sample of data** from the $10 photogate, it is very impressive considering its simplicity. If you have computers in your classroom or access to a computer lab, this is a spectacular option. You can put a photogate in EVERY student groups' hands for 1/4 the price of ONE single commercial photogate. [|PhotogateData.pdf]

Here is a **User's Manual** for the $10 photogate with installation instructions, troubleshooting tips, and suggested experiments. [|Photogate.doc]

List of alternatives to the Photo Sensor for the $50 photogate: Here is a list of suppliers who offer the Elenco K-48 Photo Sensor with Control Relay. I would recommend calling them before sending payment to be sure that they have some in stock. If you find another manufacturer that has a compatible switch, please email me at scitch@verizon.net.

http://www.esssales.com/elenco/education-kits.html http://www.cs-sales.net/phsekreask.html

Here is a schematic to build your own simple light activated relay: [|http://www.uoguelph.ca/~antoon/circ/actrelay.htm]

The 80-103 circuit on this page should also work as a substitute: http://www.philmore-datak.com/mc/Page%20251.pdf 80-103 circuit available for online purchase for $10 here: http://www.minute-man.com/acatalog/Kits_Using_Light.html or here: http://www.oselectronics.com/ose_p33.htm#LIGHT%20ALARM