Boy Scout Engineering Merit Badge - Electrical Engineering Design and Build SIMPLE MOTOR CONTROLLER

Transcription

1 Badge - Electrical Engineering Design and Build SIMPLE MOTOR CONTROLLER University of Nevada Las Vegas Electrical and Computer Engineering Las Vegas, Nevada Assistants: Mrs. Beth Schill, Jackie Schill, Teri Schill, Patti Schill, & Jessica Phillips Kit Builders: Jackie Schill, Teri Schill, Patti Schill, Jessica Phillips, & James St. Louis

2 ?Engineers? Who are Engineers? YOU Built & designed your first paper airplane or sling shot What are Engineers? Dreamers and Adventurers; Visualize, Conceptualize and Analyze Not afraid to make mistakes and to learn from their mistakes - willing to take calculated risks Take dreams and turn them into reality within the goals and constraints set by man and nature using the laws of man and nature Communicators - express their ideas to others 3

3 Our Universe & the Electr. Eng. Four Forces in Our Universe Gravitational Force; Electromagnetic Force; Strong Atomic Force; Weak Atomic Force (Nuclear Radiation; Radioactive Decay) Electrical Engineer - Harnesses Electricity Exclusively uses one of the four forces of nature - Electromagnetic Force Levels Technician level - hands on building with insight Applied researcher who works with hardware Paper and pencil designer 4

4 Electrical Engineering - Applications Electrical Power Motors and Generators Sensors Radios, TVs, Computers, & Antennas Optics and Lasers - (Camera lens) Batteries & Sources-(Microwave oven) Defense, Transportation, Environment, Safety, ALL Industries, and Science 5

5 Voltage - V the energy expended or supplied in moving charges in an electrical circuit; Battery Current - I the flow or effective flow of charges in a circuit Newton s Balls - effective flow Resistance - R the measure of difficulty of charge motion in the circuit; Resistor Law Terminology Current takes the path of least resistance R I + V - 6

6 Design and Build a Simple Motor Controller Goals and Constraints The motor is to rotate in the forward and reverse directions The motor must be able stop The battery is not to be disconnected One and only one element may be handled in the circuit when controlling the motor Added Constraint Visually see the operation of circuit 7

7 Circuit Possible Solution I R R + Motor I 1 I 2 V - R R Visual Operation - Light bulbs for Resistors Analyze Circuit - Role Play (Tools: Math. & Dr. Laws, Robert A. Schill, computer, Jr. logic, trial and error, etc.) 8 I

8 Build Circuit Build circuit Do not attach battery until after assistants have checked your circuit Make sure that all light bulbs are screwed in their sockets. Once checked, connect battery 9

9 Simple Motor Controller To Battery Motor 11

10 Test Circuit & Observations Choose one light bulb as your controller. Note the brightness of the lit bulbs. The more current and voltage supplied to a light bulb, the brighter the light!! Unscrew the bulb until the light is gone If motor does not start, try twisting the motor axial one way. If the motor still does not start, twist the axial the opposite direction. Which direction does the motor axial turn? Are all of the bulbs lit? Are they as bright as before? Stop the motor axial from spinning with your fingers. Do you notice a change in brightness in any one of the bulbs? Screw bulb back in. What happens? Short out the bulb by placing the ends of a small piece of wire across the contacts of the socket containing the bulb If motor does not start, try twisting the motor axial one way. If the motor still does not start, twist the axial the opposite direction. Which direction does the motor axial turn? Are all of the bulbs lit? Are they as bright as before? Stop the motor axial from spinning with your fingers. Do you notice a change in brightness in any one of the bulbs? Remove shorting wire. Now what happened? 12

11 The END 14

12 Circuit Parts - ~$6.80-$9.00 per station excluding batteries and holder Four No.# 14 Screw Base Lamps Radio Shack A ($1.19 pack of two bulbs) 2.47 V, 300 ma, lamp type 14, Bulb type G-3 1/2, miniature screw Four Mini Screw Lamp Base Radio Shack ($1.29 pack of four bases) One DC Motor Radio Shack ($0.99 pack of one) One 6V Battery (or 4 D size 1.5 V Batteries with holder) (~$4.00 to $6.00) One Four Position Dual Row Barrier Strip Radio Shack ($1.59 package of one) Copper wire with alligator clips on ends (optional) ($3.99 for 10 color coated wires) Radio Shack C Then, barrier strip, solder, & soldering iron not necessary Copper wire, short and long pieces, solder, & soldering iron 9 x 9 x 1 wood base and eight #6 x 1/2 sheet metal screws 15