Michael A. Covington is the associate director of the Microelectronics Laboratory, Artificial Intelligence Center, the University of Georgia, Athens. He received a degree in linguistics from Yale University, New Haven, Conn. He has worked primarily in computer science since 1984. Email address: mc@uga.edu
3 results found for Michael Covington, displaying items 1 - 3
June 12, 2008[Ideas For Design] Control Camera Time Exposure Through A Computer's Serial Port
A computer’s serial port is a convenient source of low-speed dc control signals that are easy to set from software. For example, the RTS (request-to-send) line outputs about +9 V when “on” and -9 V when “off.” This idea shows how to use this signal to control the shutter of a Canon EOS 40D camera for a computercontrolled time exposure. An ordinary cable release for this camera contains two switches, mechanically linked so that as you press the...
November 5, 2007[Ideas For Design] Tuning A Quadrature Encoder By Ear
The human ear is very good at detecting noise or missing cycles in a waveform, and since we have two ears, we can monitor two signals at once. I recently repaired an older lab instrument containing a quadrature encoder made with an incandescent lamp, a slotted disc, and two photocells (left side in the figure). It turned out that the lamp brightness, and hence the supply voltage, was quite...
May 26, 2005[Ideas For Design] LED Indicates Current Magnitude
The LED in this circuit glows in proportion to the load current (see the figure). It was designed as a very compact substitute for an ammeter in the 12-V supply line of some astronomy equipment. The equipment includes low-power heating elements (dew preventers) whose operation is not visible. However, the LED brightens visibly when the heaters are switched on, giving a positive indication that they're connected and working. Circuit...
