Links to Interesting Electronics Project Ideas, Kits, Components and Tutorials Sites: (Please

Interesting Technologies to Build a Project Around

Transducers

·  Thermo-Electric (TE) Devices: Peltier junction devices in a series string packaged as a sandwich in between ceramic sheet layers. Anodes to one side, cathodes to the other, the device is capable of creating thermal energy (hot side and cold side) for many applications including electronic cooling, refrigeration, heating. The devices are typically driven with a thermal feedback control system and a variable controlled DC current source.

·  Photo Voltaic Cells: Also known as solar cells, in single cell form these devices deliver approximately 1.2V and an output power proportional to their total cell area and the intensity (flux) of the impending light photons striking their surface. Usually constructed from single and poly crystal silicon, they can also be manufactured using amorphous technology such as cadmium telluride. Devices are typically series connected for higher voltages. This technology will start to appear more frequently in consumer applications as the cost of commercially generated electricity continues to rise. Most commonly seen as power sources for small electronics such as calculators, watches they are now becoming common for small battery or storage capacitor charging applications.

·  Peizo-Electric Devices: Available as films and crystalline devices, this technology uses the peizo-electric effect in which a material exhibits a small voltage when put into compression. Some devices are engineered to take advantage of the effect in a biased condition to allow detection of small pressure or create oscillation circuits.

·  RFID’s: This is typically a small packaged device which contains antenna, receiver, transmitter and a small amount of logic. The device responds to an incoming RF signal from a compatible “reader” and sends back a predefined code. There are many types and ranges of this technology which is rapidly decreasing in cost. Many RFID tags are available on a tape reel now.

Sensors

·  Thermal: Thermocouple and Thermistors are available alone or as a system which includes drive, sensing, linearization and digitization circuitry. Stand alone sensors are typically available with mechanical housing enabling them to thread into pipes, tanks, vessels, chassis, heat sinks and other structures. Sensors with processing circuitry are typically available in IC form or small PCB mountable packages.

·  Humidity: One of the more complex sensors types, they typically employ a small system which contains a polymer resin used as the dielectric of a capacitor designed to expand and contract with moisture. As the capacitance changes, it is detected by a sensing circuit which contains an oscillator driver and a rectification filter circuit. The DC voltage may then be scaled and linearized before made available as an output or it may be digitized and sent out as serial data.

·  Pressure: Also made with peizo-electric effect and available as small IC packaged form. Larger pressure sensors are made with mechanical housings in a threaded form to be inserted into pipes and vessels. Some sensors are designed for gas or air pressure, others are designed for sensing liquid pressures. Pressure sensors can also be constructed with LVDT and other transducer technology.

·  Light: Cadmium Sulfide Photocell, Phototransistor, Photodiode are all common forms of light sensors used for various applications. Photodiodes act as tiny current sources and are usually reverse biased which allows them to deliver more photo-electric gain or electrons out vs photons in. These devices are usually interfaced using a very high gain and high speed transimpedance amplifier. Phototransistors can be constructed as standard transistors but with based current drive from a photodiode structure on the Si die of the transistor. Lower noise in the signal can be achieved because there is very little interconnect capacitance when devices are integrated on the same die. Photocells are really resistance that change impedance when light photos strike their sensing surface.

·  Radiation: There are many types of radiation sensors devices available that offer sensing of X-Ray, Gamma Ray, Beta and Alpha particle radiation detection. However these devices usually fall into 1 of 2 categories. The first is known as an indirect conversion in which the radiation photons strike a material that has scintillation properties which allows it to convert the incoming radiation into visible light and heat. The scintillation material is mounted directly above a light sensing photodiode which then in turn generates small current proportional to the radiation flux. The second type of sensor is known as a direct conversion sensor in which a special material under bias generates small current when radiation photons strike and terminate within the material. Direct conversion sensors typically have higher photo-electric gains than indirect however they usually require high bias voltages to operate effectively. Both types of sensors are energy sensitive and care must be taken to make sure the sensor is well matched for the particular radiation spectrum and type being sensed.

·  Acceleration: Typically peizo-electric effect based, these devices are now available in small packaged IC form to detect direction and G force acceleration

·  Strain or Tensile Force: Typically a small resistor formed on a flat paper or plastic substrate this device is adhesively attached to a structural load bearing member usually metallic. As the member is tensioned or compressed, the impedance of the strain gauge changes and must be sensed by a calibrated drive and readout circuit which usually contains an instrumentation amplifier circuit.

·  Ph: These temperature sensitive devices usually deliver a small change in output voltage or current with respect to changing acidity of solutions they are sensing. They are usually coupled with a temperature sensor to allow proper calibration of the Ph sensor.

Links to Interesting Electronics Project Ideas, Kits, Components and Tutorials Sites: (Please let us know if any of these do NOT work so we may update)

·  http://www.web-ee.com/

·  http://www.electro-tech-online.com/

·  http://www.hallbar.com/

·  http://www.electronics-lab.com/

·  http://www.electronickits.com/

·  http://www.proaxis.com/~iguanalabs/micropro.htm

·  http://my.integritynet.com.au/purdic/

·  http://www.knowledgehound.com/topics/electron.htm

·  http://www.juliantrubin.com/electronicsprojects.html

·  http://www.electronicsforu.com/electronicsforu/top100/top100electronics.asp

·  http://ee.cleversoul.com/projects.html

·  http://www.hvwtech.com/pages/default.asp

·  http://dir.yahoo.com/Recreation/Hobbies/Electronics/

·  http://electronicsusa.com/

·  http://www.uoguelph.ca/~antoon/circ/circuits.htm

·  http://www.amasci.com/amateur/elehob.html

·  http://www.hobbytron.com/electronickits.html

·  http://www.siliconchip.com.au/menu_1599/section_articles/cms/section.html

·  http://www.ce.ucsb.edu/senior%20elective%20descriptions.htm#ECE

·  http://www.cet.nau.edu/Academic/Design/D4P/Projects/486-projects.htm

Other University Capstone Project Sites:

·  http://services.eng.uts.edu.au/~gdissa/capstone/

·  http://www.msoe.edu/library/mse/

·  http://ctas.east.asu.edu/post/capweb/projdir.htm

·  http://www.cs.washington.edu/info/videos/

·  http://www.cet.nau.edu/Academic/Design/D4P/Projects/486-projects.htm - ee

·  http://www.isu.edu/engineer/srdesign.html

·  http://doc.union.edu/cse/capstone_projects.html

·  http://scpm.ltc.arizona.edu/projects/

·  http://www.coe.neu.edu/Depts/SET/set/capstone.html

·  http://www.ece.ualberta.ca/~ee401/index.html

·  http://www.eng.lsu.edu/news_events/news.stories/students.capstoneII.html

·  http://www.seas.virginia.edu/news/context.php

·  http://ece-www.colorado.edu/academics/ug/expo.html

·  http://engineering.lssu.edu/Students/seniors.html

·  http://www.uidaho.edu/engr/ME/sr_des/

·  http://www4.nau.edu/insidenau/bumps/5_4_05/capstone.htm

·  http://www.widener.edu/Academics/Schools_amp_Colleges/School_of_Engineering/Current_Students/Undergraduate_Programs/Senior_Projects/1525

General Science Project and Hobby Interest Sites:

·  http://www.exploratorium.edu/

·  http://www.einsteins-emporium.com/science/l-optics/sl210.htm

·  http://www.explorescience.com/index.cfm

·  http://www.ipl.org/youth/projectguide/

·  http://www.mcrel.org/whelmers/

·  http://www.isd77.k12.mn.us/resources/cf/

·  http://www.eskimo.com/~billb/

·  http://scienceclub.org/scifair.html

Classic Electrical and Electronic Projects

Uniterruptable Power Supplies and DC-AC inverters

High Efficiency, Low Power Digital Control and Display Systems

Wireless Remote Sensors – Temp, Pressure, Humidity, Moisture, Level, Acceleration, etc

Biomedical Sensor Systems – Blood Pressure, Temp, ECG, EKG, Pulse, Respiration

Alarm Systems including Remote Sensors and Remote Access via Internet, Telephone

Smart Telephone Answering Systems

Large Array Displays for A/N info or High Visibility Stroboscopic Emergency Vehicle

Smart Controllers including Vehicles, Motor Drives, Appliances and Tools

Wireless Controllers utilizing off-the-shelf AM and FM RF communication blocks

RF Synchronized Clock Controllers such as WWVB

Battery Charging Systems

Environmental Controllers incl Cooking, Warming, and HVAC

Wireless Data and Audio Communications Systems

High Fidelity Audio and Video Amplification, Equalization and Distribution Systems

AM, FM, or SW Digitally Controlled Radio Receiver

Robotic or Radio Controlled Vehicles

Differential Ground Noise Measurement System

RF Location Systems