An Inexpensive Computer-Controlled Photogate

Budgetary constraints have hit almost every science department, from high schools to community colleges and research universities. While some institutions manage to fully fund their physics laboratories, others are not so fortunate and must do without some modern equipment. One of these conveniences, electronic data devices such as photogates, can greatly facilitate data collection and improve the student's laboratory experience. The photogates themselves are not particularly expensive but require additional hardware and software to connect them to a computer. Though sometimes useful and often convenient, these “black boxes” greatly increase the overall cost of data collection and can place a computer-based physics laboratory out of the reach of many instructors. Though specialized scientific equipment has remained expensive, the price of most other computer-based technology has decreased rapidly. This paper will outline the procedure for creating a “do-it-yourself” photogate system by connecting a purchased photogate directly to a computer. The result is a data collection system whose cost and maintenance is well within reach of most physics labs.