The amount of current drawn and the temperature generated by DC motor are crucial in understanding the performance and reliability of motors.

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1 1/1/1 Fall 1 Honore Hodary Motivation Overheating is one of the most common cause of failure in DC motors. It can lead to bearings failure (motor jam), winding isolation (short circuit), and degradation of the magnets. The amount of current drawn and the temperature generated by DC motor are crucial in understanding the performance and reliability of motors. Provide a low cost and effective tool for measuring the amount of current drawn and heat generated by DC motors. 1

2 1/1/1 Goals Provide a cost effective mechanism for acquiring temperature and current data. Allow the operator to determine when to perform preventive maintenance. Record the temperature and current data to a host computer. Display current and temperature data on LCD Design a compact, portable, and user friendly system. Functional Requirements Measure the heat (temperature) generated by the motor. Measure the amount of current drawn by the motor. Record temperature and current data to a host computer for later analysis. Display current and temperature data on LCD display.

3 1/1/1 Specification Measured temperature shall be in the range of to degrees Fahrenheit. Measured current shall be in the range of 1 to 15 A. The temperature accuracy shall be within + degrees Fahrenheit. The current accuracy shall be within + 1 ma Both temperature and current should be transmitted to a host computer every seconds. The operating temperature shall be between and 1 degrees Fahrenheit. The system shall not exceed lbs. System Block Diagram

4 1/1/1 Subsystems Sensors module Power supply module Microcontroller module Data display module Data storage module Signal conditioning module Sensors Selection Criteria Transfer function must be linear Response time must less than 1 ms Must have great accuracy Noise level must be less than 1 mv Dynamic range must be between A and 15 A Must be easy to use

5 1/1/1 TLS 15 NP Current Sensor Type: Hall Effect Maximum measure current: 15 A Supply voltage: 5V Supply current: 1. ma Output type: voltage Response time: <1 ns Sensitivity: 1. mv/a TLS 15 NP 5

6 1/1/1 CSLACD Current Sensor Type: Hall Effect Max Current: A Supply Current:1 ua Supply Voltage: 8V 1.V Output type: Voltage Response Time:us Sensitivity:. mv/a CSLACD Sensor

7 1/1/1 Sensors (Continued) Temperature Sensor (LM) Internally calibrated Linear Output: 1mV/Degree Fahrenheit Supply Voltage: 5V to V Supply Current:5 ua Response Time:5 ms Measurement Range: 5 to Degrees Fahrenheit Accuracy: + Degrees LM Sensor

8 1/1/1 DS18 Dynamic range: to 5 Accuracy:.5 degrees Fahrenheit Resolution: 1 bits Cost: $. DS18 8

9 1/1/1 Op Amp Selection LM 1 Dual power supply Well balanced Easy to use CMP1 Single supply Requires virtual ground Hard to design Single Supply Op Amp 9

10 1/1/1 Signal Conditioning Module Temperature Sensor Signal Conditioning Circuit 5V C1 Vin.1µF U1 Vout VDD 5 V R1 15Ω RG MCP1-I/P RF R 8Ω C.1µF kω 9kΩ 1

11 1/1/1 Current Sensor Signal Conditioning Circuit Vin 5V C1.1µF U5 MCP1-I/P R 5V C.1µF U MCP1-I/P R R11 1kΩ 1.nF R1 1kΩ C 8pF C8 C9 5V.1µF U MCP1-I/P Vout R5 8Ω C.1µF R 15Ω kω VDD 5 V 9kΩ Power Supply Wall adapter Input: 11V 15V Output: 1V Current: 1A Regulator Type: LM85 Voltage: 5V Current: 1A 11

12 1/1/1 Power Supply Schematic 1NG D1 Input C1.1µF U1 LM85CT LINE VREG VOLTAGE COMMON Output C.1µF USB Communication Module FTR Controller Provides communication channel between the MCU and the host computer. Converts USB port to Virtual COM port in the host computer. Manages enumeration and other USB bus communication requirements in hardware. No USB specific firmware required. Supports Bus powered and Self powered. USB. full speed compatible. 1

13 1/1/1 USB Controller (continued) Operating temperature: to 85 degrees C. Supply voltage: 1.8V to 5.5V. Supply current: 15mA Data transfer: baud to Mbaud. USB Controller Schematic 1

14 1/1/1 Microcontroller PIC18F55 Analog to digital conversion (ADC) Process temperature and current data. Transfers temperature and current data to the host computer. Display temperature and current data on LCD display. Microcontroller Communication With USB Controller Communication With DAC Communication with LCD display 1

15 1/1/1 Microcontroller (continued) Supply voltage: V to 5.5V Supply current: 5.8 ua Sink/source current: 5mA Clock: Internal and external oscillator. Timers: ADC resolution: 1 bit Analog channels: 1 Interrupt sources: Microcontroller Schematic 15

16 1/1/1 1 System Integration U UMR U MCP1-I/P R kω R 9kΩ C.1µF C.1µF R5 8Ω R 15Ω U MCP1-I/P R11 1kΩ R1 1kΩ C 8pF C8 1.nF C9.1µF U5 MCP1-I/P C1.1µF J PJ-1A U GND CV RS RW E D D1 D D D D5 D D U8 LM85CT LINE VREG COMMON VOLTAGE D1 1NG C5.µF C.1µF D 1NG S1 Key = Space 5V U1 LTSR 15_NP J1 HDR1X 1 Isense_In Isense_Out OUT C1.1µF U MCP1-I/P R8 1kΩ R9 1kΩ C 8pF C11 1.nF C1.1µF U9 MCP1-I/P R1 kω R 1kΩ RG kω RF 1kΩ C1.1µF U1 MCP1-I/P J HDR1X 1 U11 PIC18F R 1kΩ C1 pf C15 pf X1 HC-9/U_11MHz AN AN AN1 AN1 RB RB RB RB RB1 RB1 RB RB RB5 RB5 RB RB Software Architecture

17 1/1/1 Software: Microcontroller Programming language: C Program Initialization Configure ports Configure ADC Configure USART ADC Conversion Reads data from analog channels Format data Data transfer/display Transfer data to the host computer Display data on LCD display Algorithm: Microcontroller 1

18 1/1/1 Statechart Testing and Validation 18

19 1/1/1 Testing and Validation Cost and Resource Management Part Name Quantity Price Per Unit Total Cost MCP1 Op Amp $. $. $. TLS 15-NP Current 1 $1. $1. $1. Sensor LMDZ Temperature sensor 1 $. $. $. Actual Amount of Money Spent Resistors 1 $1.(per kit) $1. $. (Had it ) Capacitors 15 $9. (per kit) $9. $. (Had it) UMR USB-to- 1 $11. $11. $1. UART Converter PIC18F55 1 $.9 $.9 $.(Had it ) Terminal Blocks $1. $. $. (removed from power supply) Barrel power Jack 1 $. $. $. (removed from an old router) Diode $. (per kit) $1. $. (purchased two years ago) Oscillator 1 $. $. $. (Had the part in my tool box) Total $9.1 $8. 19

20 1/1/1 Risks The microcontroller not sending data to PC The temperature sensor not being attached to the motor Lesson Learned Project management Planning is key to a successful project Always buy extra components in case one get damaged Gained valuable experience in analog signal conditioning Gained experience programming PIC microcontroller

21 1/1/1 Conclusion All features of the USB Based Data Acquisition System were successfully implemented The cost of designing the UBS Based Data Acquisition System was well bellow $1 Did not have enough time to focus on the project as given my work related responsibilities Overall, this was a very rewarding experience Thank you. Questions? 1