Electronic Shows 1995-99

1995 Electronics Show – The First

Range Finder with Analog Output	Derek Yoder Dave Snyder	An ultrasonic rangefinder connected to a circuit that gave an analog output.  For the show, they hooked it up to a pair of eyes that would (crudely and spastically) follow you as you moved across in front of them
A Kinder and Gentler Alarm Clock	Leon Headings Matt Martin	When an electric alarm clock triggered this, it slowly turned on a lamp, then it began to beep very gently but eventually growing to full volume.
AM Transmitter	Nick Blank Aaron Krieder Peter Subianto	As if to prove the difficulties of buiding transmitter circuits (which are outside the scope of the class) This circuit had the ability to transmit a crude audio signal about 10 feet using an 20 foot antenna
Guitar Wah-Wah Filter	Rick Yamazaki Eric Harley	These students entertained us during the show with one of them playing guitar while the other manipulated the controls of the filter.  It was a state variable band pass with adjustable center frequency, gain, and Q.
Digital Range Finder	Vern Guerin Nick King	Built with discrete logic circuits, the signal from an ultrasonic rangefinder was turned into a digital count shown on LEDs.  At the show it displayed your distance from it, continuously updated as you moved.
4-Digit Digital Lock	Aaron Stuckey Phil Swartzendruber	The user must enter a 4 digit code to “open” the lock    It was built entirely of CMOS 4000 series logic chips. A design flaw enabled the professor to dramatically crack it during the show without knowing the preset code.  Their final exam question was to fix the flaw.

1997 Electronics Show

Refrigerator Finder	Klaus Huebert Kerry Stump	It beeps in response to a whistle, similar to the keychains that respond to a clap to help you find them.  The size of this project suggest a more appropriate use might be to find the refrigerator when you stumble down in the dark for a midnight snack.  Klaus seemed to be the only one who could consistently whistle just the right pitch and volume to trigger it.
Sound Trigger for flash	Ryan Good Monte Hackney	They made some interesting pictures of breaking objects using their circuit to fire a flash unit when it picked up a sound.
Squealer for x-ray detector	Rob Christner Alex Naula	When setting up x-ray experiments it is difficult to simultaneously watch the things you are adjusting and watch a ratemeter.  This circuit takes the pulses from an x-ray detector and turns them into an audio squeal whose pitch tells the x-ray intensity.
Suspended steel ball	Ramont Schrock Kevin Jantzi	A steel ball suspended under a magnet.  The ball casts a shadow on a sensor to measure its position.  Then the circuit uses that as feedback to adjust the strength of the magnet and keep it suspended.    Unfortunately this one was still not working the night before the show.  I (JRB) was determined to get it to work and finally at about 1 AM, I succeeded, the ball was hanging for minutes at a time.  Sadly, on the morning of the show it was again refusing to work.
Shadow AC Switch	Jon Hartzler Bryce Miller	Interrupting an infrared beam turned on power to a lamp.  It stayed on while it counted down the remaining seconds till it shut off again.
Laser listener and modulator	Nate Pletcher Steve Troyer	Laser beam transmission of voice from the lobby though the glass to Doris’s office.  The transmitter used a microphone and audio amplifier which varied the power supply of a laser pointer so the beam intensity carried the audio signal.  The receiver used a photocell to change the light intensity back to an electrical signal which was amplified and drove a speaker.
Parallel to serial and back	Tim Dueck Rachel Amstutz	This was a concept demonstration.  By turning a rotary switch you select a 4 bit parallel “message”.  Using discrete digital gates and registers, the encoding circuit converts this into a serial signal sent over a single wire to the receiver.  Then a decoding converts is back to parallel and displays  it as a single BCD digit.

1999 Electronics Show

Entropy Reducer (Candy Color Sorter)	Ned Mast Kevin Graber	Colored candy rolled past two light sensors with color filters to determine the color of the candy and kick it into the appropriate bin. Though in principle it should have worked, the sensors we used proved to be mostly sensitive in the infrared where the candy all looked the same.
Laser Tag System	Dustin Brubaker Geoff Owens	Boxes covered with photocells to detect a laser spot.  Parts of the system worked, then instead of using breadboards, the students insisted on constructing permenant versions which never worked.
Meter Stick Balancer	Carl Meyer Peter Byler Peter Fairfield	Used ultrasonic rangefinders alternating pulses from two directions to determine the position of the stick.  An analog proportional and derivative computer created control signals which then were digitized to control stepper motors which shifted the platform.  Two large breadboards were packed with about 50 chips total.  It all individually worked but the system was unable to balance the stick.  If you held the stick and moved the top around, the platfrom would very spastically follow your movement.  The hardware (loose strings on pulleys) left a great deal to be desired.  This project was tried repeatedly in future years.
Mouse Controlled Laser Pointer	Ezra Nugroho Geoffrey Christanday	A tilt platform was interfaced to a computer (through the parallel port?). In response to mouse movements the software would output pulses to the port lines.  These were used to drive stepper motors moving a tilting platform to which a laser pointer was attached.  So the laser spot copied the mouse movements.
AM Radio Transmitter	Marten Beels Peter Sprunger	At one point they were successfully transmitting the length of the hall.