Spring 2017 Prosthetic Arm: Buck Converter LTSpice Simulation
The Robot Company | CEO Dr. Gary Hill
Blog Post Created by Project Manager | Bianca Esquivel
Project Simulation Executed by Mission, Systems, and Test Engineer | Phuong Tran and Electronics and Control Engineer | Mikael Movsisyan
Table of Contents
Preliminary Information
Test Objective
This experiment was performed in response to requirement
L2.2.1 Wrist Rotation: The prosthetic hand shall provide 90 degree rotation at the wrist. (clockwise/counterclockwise)
Problem: Determine if the buck converter can step down the input voltage of 11.1V (from the Li-Po battery) to 5V, the necessary voltage required to drive the servos.
Materials
Software:
LTSpice
Test Set Up
Procedure:
Step 1: Obtain schematic of the LT3971-5 from the datasheet [Fig. 1]
Step 2: Construct circuit with appropriate electronic component values on LTSpice
Step 3: Run simulation until system response reaches steady state conditions
Step 4: Place a voltage and a current probe at the output Vout
Results
Conclusion
The result of the LTSpice simulation satisfies the supply voltage for the servo. The 11.1V input voltage is stepped down to 5V. The current output reaches up to 1.2A at steady-state and is more than enough to power the servo at the wrist (+ hand servo). Hence, this buck converter can be used in our design for the PCB.