Introduction to Engineering Lab 4 – 1 Basic Data Systems & Circuit Prototyping Agenda REVIEW OF LAB 3 RESULTS DEFINE a DATA SYSTEM  MAJOR TYPES  ELEMENTS BUILD and USE TWO ELECTRICAL CIRCUITS

LAB 3 REVIEW EFFECT OF ADDING A RESISTOR IN PARALLEL WITH ORIGINAL  BRIGHTNESS OF LED  VOLTAGE ACROSS LED EFFECT OF ADDING A CAPACITOR  CIRCUIT ‘RC’ TIME RESPONSE

LAB 3 REVIEW ADDING A RESISTOR IN PARALLEL  EFFECTIVE RESISTANCE is HALVED  CURRENT is NOMINALLY DOUBLED (If V is constant), REF. OHM’S LAW V=IR  CURRENT THROUGH THE LED is NOMINALLY DOUBLED…ITS LIGHT INTENSITY INCREASES.  LIGHT INTENSITY FROM THE LED is PROPORTIONAL to CURRENT

Case 1: One resistor only Voltage at AA: 5.22 V Case 2: Two resistorsVoltage at AA: 5.22 V * SAME VALUE BECAUSE it is the SUPPLY VOLTAGE

Case 1: One resistor only Voltage at BB: 1.98 V Case 2: Two resistors Voltage at BB: 2.01 V *VERY SLIGHT VARIATION of VOLTAGE across the LED (0.03 V) What did we do by connecting another resistor in parallel? Resistance halved Current doubled ( V= IR) But only a … So the DIODE can be a REGULATOR of VOLTAGE

LAB 3 REVIEW WHEN A CAPACITOR IS ADDED TO THE CIRCUIT AND THE SWITCH LEVER IS PRESSED, THE CAPACITOR VERY QUICKLY ACQUIRES AND HOLDS AN ELECTRICAL CHARGE WHEN THE SWITCH LEVER IS RELEASED, THE CAPACITOR HAS TO DISCHARGE (RELEASE ITS CHARGE) THROUGH THE RESISTANCE AND THE LED

LAB 3 REVIEW SINCE RESISTORS ‘RESIST’ THE FLOW OF CURRENT, THE LARGER THE RESISTANCE VALUE, THE LONGER TIME IT TAKES FOR THE LED TO TURN OFF THE CIRCUIT TIME RESPONSE IS ACTUALLY PROPORTIONAL TO THE PRODUCT OF RESISTANCE AND CAPACITANCE (RC) AND THAT PRODUCT IS THE ‘RC TIME CONSTANT’ FOR THE CIRCUIT

LAB 3 REVIEW ANY GENERAL DIODE HAS AN ASSOCIATED FORWARD VOLTAGE ABOVE WHICH IT CONDUCTS CURRENT AND BELOW WHICH IT CONDUCTS VERY LITTLE CURRENT FOR THE LED WE USED, THE THRESHOLD OF THE FORWARD VOLTAGE WAS ABOUT 1.7 VOLTS

LAB 3 REVIEW THE TIME FOR THE LED TO TURN OFF (VOLTAGE DECREASE TO 1.7 VOLTS) WOULD NOMINALLY BE TWICE AS LONG IF THE RESISTANCE INVOLVED IS DOUBLED TIMES WITH ONE RESISTOR SHOULD BE NOMINALLY DOUBLE THE TIMES WHEN TWO RESISTORS ARE IN PARALLEL

TYPES OF ELECTRONIC DATA SYSTEMS DIGITAL  OPERATION EXHIBITS A FINITE NUMBER OF DISCRETE CONDITIONS OR SAMPLES (e.g., ON/OFF) AND IS RELATIVELY INSENSITIVE TO NOISE ANALOG  OPERATION EXHIBITS AN INFINITE NUMBER OF DIFFERENT CONDITIONS AND IS RELATIVELY SENSITIVE TO NOISE HYBRID  MIXED DIGITAL/ANALOG

ELEMENTS OF AN ELECTRONIC DATA SYSTEM TRANSDUCERS (SENSORS) SIGNAL CONDITIONING DATA PROCESSING and CONTROL ACTUATORS DATA DISPLAY AND/OR RECORDING ELECTRICAL POWER SOURCE CONNECTION OF ELEMENTS

BASIC DATA SYSTEM SCHEMATIC SENSORS SIGNAL CONDITION- ING DATA PROCESSING and CONTROL DISPLAYING ELECTRICAL POWER RECORDING ACTUATORS TO PROCESS FROM PROCESS

TRANSDUCERS  TRANSDUCERS (SENSORS) are used to TRANSLATE a MEASURABLE PROPERTY into a USEABLE (usually electrical) FORM  A few MEASURABLE PROPERTIES are: MOMENT ACCELERATION FREQUENCY SIZE PRESSURE TEMPERATURE STRAIN FORCE

TRANSDUCERS Strain Gages Thermocouples and Temperature Probes Photos from Omega, Inc website

TRANSDUCERS Pressure Transducers Photos from Omega, Inc website

SIGNAL CONDITIONING  PROVIDES VERY STABLE POWER SOURCE  AMPLIFIES THE SIGNAL (makes it ‘stronger’ and more useable)  FILTERS THE SIGNAL (‘cleans it up’)  EXHIBITS LOW OUTPUT IMPEDANCE (good for noise insensitivity)

DATA PROCESSING and CONTROL  ROUTING or MANIPULATION of DATA SIGNAL OCCURRING AFTER SIGNAL CONDITIONING  COMMONLY INCLUDES CONVERSION to a DIGITAL SYSTEM (for processing by computer)  CONTROL SECTION (actuator control)  DISPLAY and/or RECORDING of the DATA are GENERALLY the FINAL PROCESSES

ACTUATORS AN ACTUATOR is a DEVICE which PERFORMS an ACTION to INFLUENCE a PROCESS

ACTUATORS SOLENOID VALVE PICTURE FROM SNAP-TITE, INC. WEBSITE Solenoid Valve RELAY PICTURE FROM RADIO SHACK WEBSITE DPDT Relay

ACTUATORS DC Gear Motor Permanent Magnet DC Motor Photos from Peerless-Winsmith, Inc website

DISPLAY and RECORDING  STRIP CHARTS  COUNTERS  DIGITAL MULTIMETERS  OSCILLOSCOPES  COMPUTERS Ca

DISPLAY and RECORDING Strip-chart recorder Counter

DISPLAY and RECORDING Digital Multimeter Oscilloscope

DISPLAY and RECORDING Picture from RadioShack Web site Computer system

ELECTRICAL POWER SOURCES  CHEMICAL  BATTERIES  FUEL CELLS  ELECTRICAL  AC TO DC POWER SUPPLIES  DC TO DC POWER SUPPLIES  MECHANICAL  GENERATORS  ALTERNATORS  SOLAR  PHOTOVOLTAIC CELL (PV) SYSTEMS

CONNECTION OF ELEMENTS PERMANENT or TEMPORARY  HARD WIRE (copper or optical)  LIGHT BEAMS  ULTRASOUND  RADIO FREQUENCY (RF)

Assignment Read Lab 4 procedure carefully