Transcript Power Systems - California University of Pennsylvania

By: Team Leroy Jenkins
Leader:
Hardware Specialist:
Software Specialist:
Assistant:
Amos Friend
Luke Noschese
Jacob Longwill
Ryan Trump
 Understand the Problem
 NimH Batteries
 Charge and discharge graphs
 Hardware
 Software
 Summary
 References
 Q&A
 Power Systems
 Clean accurate power to respective components
 Safeguard against destroying components with too
much power
 Understanding power output of the batter as it drains
 Displaying battery life
 Use on-board LED to change color depending on battery
life.
 Battery NiMH (Nickel-Metal Hydride)
 LM2940 or 4941 LDO Regulator (5v Volts)
 MCP1702 or 1700 LDO Regulator(3.3 Volts)
 2x 4.7KΩ
 5 Capacitors of different values
 Nickel–metal hydride
battery
 Does not have Memory
Effect as NiCd did
 7.2v battery
 Output can go as high as
~9.5v when fully charged
 3000mAh battery
 6-cell
 Each cell
 1.2v
 3000mAh
 Different groups have different 5v and 3.3v regulators
 Use only two voltage regulators
 1 – 5v regulator
 1 – 3.3v regulator
 3 outputs
 Directly from Nimh battery
 5v output
 3.3v output
 Voltage Divider
 If full battery voltage is
supplied it will destroy
the port
 Divide voltage in half
 Multiply by 2 in code
 To display correct
voltage on LCD
 Remember to ground the
board and battery to a
common ground
 Large capacitor is needed after 5v regulator for rapid
power drain from servo
 5 VOLTS @ MAX 1 AMP
 MAX INPUT 26V
 LOW DROPOUT VOLTAGE
 500mV @ 1A
 5 VOLTS @ MAX 1 AMP
 MAX INPUT 26V
 LOW DROPOUT VOLTAGE
 250mV @ .5A
 3.3 Volt
 Operation range
 2.5v-6v
 Output current 250mA
 Low Dropout Voltage
 350 mV typical @ 250
mA (VOUT = 2.5V)
 Looks similar to a
transistor
 3.3 Volt
 Operation range
 2.8v-13.2v
 Max out 250mA
 Low Dropout Voltage
 625 mV typical @ 250
mA (VOUT = 2.8V)
 Looks similar to a
transistor
 Flowchart for battery output
 Varibles
 #define VBMIN 500
 int VBATT;
 FB_RGB_ENABLE;
 FB_RGB_ON;
 Call Batcheck In Forever Loop

void BATCHECK(void){
ADCSC1 = 10;
11-bit ADC on PTD3
WAITFOR(ADCSC1_COCO);
// start
// wait for conversion complete (new technique)
VBATT = ((((ADCR * 500)/1023)*2));
if (VBATT >= VBMIN && VBATT < VBMIN*(3/2))
{
FB_RGB_BLUE = 0;
FB_RGB_GREEN = 1;
FB_RGB_RED = 0;
}
else if(VBATT < VBMIN)
{
FB_RGB_BLUE = 1;
FB_RGB_GREEN = 1;
FB_RGB_RED = 0;
motorDC = 0;
}
else
{
FB_RGB_BLUE = 1;
FB_RGB_GREEN = 0;
FB_RGB_RED = 1;
}
 PROBLEM STATEMENT
DISTRIBUTING PROPER VOLTAGE TO VARIOUS PARTS OF THE
SMART CAR
 MONITORING BATTERY STATUS

 HARDWARE
 REQUIREMENTS/CONCEPTS
 INTERFACE
 SOFTWARE
 DESIGN
 CODE

250 MA Low Quiescent Current LDO Regulator." Microchip Technology Inc. Microchip Technology
Inc., n.d. Web. 11 Mar. 2014.

"ALIMENTAZIONE." ALIMENTAZIONE. N.p., n.d. Web. 11 Mar. 2014.

"L4941 Very Low Drop 1A Regulator." STMicroelectronics, n.d. Web. 11 Mar. 2014.

"LM2940/LM2940C 1A Low Dropout Regulator." Texas Instruments. Texas Instruments, n.d. Web. 11
Mar. 2014.

"Nickel–cadmium Battery." Wikipedia. Wikimedia Foundation, 28 Feb. 2014. Web. 11 Mar. 2014.

"PDIP | ChipKIT Development Platform." ChipKIT Development Platform. N.p., n.d. Web. 11 Mar.
2014.
"Voltage Divider." Wikipedia. Wikimedia Foundation, 03 JulY2014. Web. 11 Mar. 2014.
MCF51JM128 Reference Manual
Notebook reference CET 335 lab 7 Analog to Digital Input
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