4e . MOTOR SIZING AND BATTERY SIZING - M-Division-2020-2021-Even/Repo_01 GitHub Wiki
BATTERY AND MOTOR SIZING
Motor Sizing
DC MOTOR
Dimensions of Spool= 12cm * 9cm * 9cm
Diameter of Spool= 9cm = 0.09m
Mass= 300gm = 0.3kg
Coefficient of Friction (COF)= 0.4
Factor of Safety (FOS)= 1.5
Force= Mass * COF * 9.8
= 0.3 * 0.4 * 9.8
= 1.176 N
Torque= Force * radius
= 1.176 * 0.045
= 0.05292 Nm
Torque= 0.05292 * 100/9.8
= 0.54 kg cm
TORQUE= Torque * FOS
= 0.54 * 1.5
= 0.81 kg cm
Hence, DC motor of 12V 100rpm is suitable.
SERVO MOTOR
Dimensions of the Thread guide = 10 * 1 * 0.6 cm
Mass = 0.02 kg
Coefficient of Friction (COF)= 0.4
Factor of Safety (FOS)= 1.5
Force= Mass * COF * 9.8
= 0.02 * 0.4 * 9.8
= 0.0784 N
Torque= Force * radius
= 0.0784 * 2
= 0.1568 N cm
Torque= 0.1568 / 9.8
= 0.016 kg cm
TORQUE= Torque * FOS
= 0.016 * 1.5
= 0.024 kg cm
Hence, Tower Pro SG-90 servo motor is most suitable.
Battery Sizing
| Sl .no | Components | Quantity | Voltage | Current | Total current |
|---|---|---|---|---|---|
| 1 | Arduino | 1 | 5V | 100mA | 100mA |
| 2 | Buzzer | 1 | 5V | 30mA | 30mA |
| 3 | DC motor | 1 | 12V | 300mA | 300mA |
| 4 | Servo motor(Tower Pro SG-90) | 1 | 5V | 650mA | 650mA |
| 5 | LCD screen | 1 | 5V | 100mA | 100mA |
| 6 | LED | 1 | 5V | 50mA | 50mA |
| 7 | PIR sensor | 2 | 5V | 40mA | 80mA |
Power supply to the system : Adapter
12V 300mA : 5V 1010mA
F.O.S = 1.2
12V 360mA ; 5V 1212mA
The design specifications include adapter of 12V 0.5A or 5V 1.5A .