Sensors @ Adafruit

December 4, 2009

You can get a variety of sensors from Adafruit.  Lady Ada also posts good tutorials on how to use these sensors and many other things they sell.  Much of her work and product line focuses on the Arduino board, but there is still a lot of good stuff and information outside of that.

handy online calculators

November 30, 2009

Resistor color code converter

Resistor color code converter with table

 

Resistor calculator for LEDs

 

Ohm’s Law calculator

555 timer

November 30, 2009

Information on 555 Timers:

Online Calculators:

Monostable Mode Schematic:

555monostablemode3

Note: C is in Farads (Example: 100 uF = 0.0001 Farads)

Astable Mode Schematic:

555astablemode

Note: C is in Farads (Example: 100 uF = 0.0001 Farads)

Bistable Mode (Flip-Flop) Schematic:

555bistablemode1

Relays

November 30, 2009

Relays are electronically actuated switches which allow smaller voltage, low current sources to control large voltage, high current loads.

A relay can either be mechanical or solid state. Mechanical relays can handle high current loads, while solid state relays are capable of rapidly switching. The solid state component we will use is called a transistor.

Transistors must be oriented properly to operate (see below). Great care must be taken when using handling transistors, as they are very sensitive to static electricity. It is actually possible to damage a transistor by walking around carrying it by its 3 legs! Thankfully they are very inexpensive. Transistors are often used to trigger mechanical relays.

Mechanical relays are much more resilient, though they can still be damaged by too much voltage or current. Relays are rated by the amount of voltage needed to trigger their electromagnetic coil and the maximum current they can handle. They will also list the maximum voltage rating, and whether they are AC, DC, or both. The trigger voltage can be successfully approximated by 25% and still function properly. Adiode placed between the relay’s coil terminals is used to protect the source circuit from blowback voltage generated when the relay is switched off.

Diodes are polarized components which allow electrical current to flow through them in one direction. Use a 1N4004 or similar rectifier diode.

Mechanical relays come in a variety of different types based on their connections. Some common types include SPDT (Single Pole Dual Throw) and DPDT (Dual Pole Dual Throw). Unfortunately, these configurations are not standardized, so the pin layout will vary from model to model (see below for the relays demonstrated in class). Two pins will always control the relay’s Coil. Passing current from a small source through these pins will cause the relay to control the load. A Dual Throw component will have a shared pin (Common) and a NC (Normally Closed) and NO (Normally Open) pin which allow you to control the current in opposite ways.

Click on image below to enlarge.

Darlington Pair

November 30, 2009

To review the information on transistors and the Darlington pair that we discussed in class, check out the wonderfully informative Electronics Club web site.

Intro to Electronics

November 30, 2009

Intro To Electronics Lecture

intro to electronics handout

Shift – Kinetic Sculpture Exhibit at DCCA

November 6, 2009

The Delaware Center for the Contemporary Arts is currently exhibiting a show of Kinetic Sculpture entitled Shift. Much of the work actually looks pretty good.   Field trip?

 

The Plan

November 5, 2009
10 9-Nov In Class
Lecture- Introduction to Electronics
Demos
Presentation on suppliers
Homework
Makes circuits
Field trip to Crazy Ray’s – mabye Show in Deleware
Scavenge motors, parts, electronic components, and power supplies
Plan final piece
11 16-Nov In Class
Demos continued
Discuss ideas for final
Homework
Develop drawings and prototypes for final
12 23-Nov In Class
Review sketches, drawings, prototypes
Complete prototypes
Homework
Make materials/parts list
Diagram electronics
Begin working on piece
13 30-Nov In Class
Studio work day
Homework
work on Final
14 7-Dec In Class
Studio work day
Homework
finish final
15 14-Dec In Class
Critique

Electronics Suppliers

November 4, 2009

Retail Suppliers

  • Electronix Express – Inexpensive place to buy hookup wire, soldering irons, super economy multimeters, and some surplus. Located in New Jersey.
  • Jameco Electronics – Huge inventory, highly illustrated catalog. Good for beginners. Located in California.
  • Digi-Key – They have everything. Catalog can be a little intimidating. Think McMaster-Carr of electronics. Located in Minnesota.

Surplus

  • All Electronics – Very reputable California surplus company. Good place for geared motors, relays, and solenoids. Some sprockets and roller chains. Fast shipping.
  • American Science & Surplus – Good supplier of motors and other oddities. Retail locations in Illinois. Fast shipping.
  • Burden Surplus – Lots of geared motors, pneumatic cylinders, sprockets, roller chains. Good prices, but slow to ship. Located in Nebraska.
  • Crazy Ray’s – Local auto junkyard. Relatively cheap source of anything pullable from a car.

The Uncanny Valley

November 4, 2009

This is a diagram Masahiro Mori used to describe “the uncanny valley” in his 1970 article of the same name.

Found on the “Toward Social Mechanisms of Android Science” conference website.


Follow

Get every new post delivered to your Inbox.