<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">To all, <div><br></div><div>Since I can’t make it to the meeting on Monday, I wanted to share my most recent creation and see if it sparks any interest. I have been working on some switching power supply designs with Pete and I got all excited about the <a href="http://www.ti.com/lit/ds/symlink/tps63030.pdf">Texas Instruments TPS63031</a> Buck-Boost 3.3V DC DC converter which could handle input voltages from 5.5 down to 1.8 volts. I got it in my head that it would be neat to build a test rig which would allow me to test different converter designs and different battery chemistries, sizes and packages. Here is what I cam up with:</div><div><br></div><div>The setup uses a relay to connect a battery pack to a constant 165mA load. Every ten seconds, I measure the input and output voltage and current and log it to the terminal in a table I can then analyze to compute the efficiency as the voltage from the battery drops and the converter moves from buck - to pass through - to boost modes. </div><div><br></div><div>I have documented the components and their connections in the sketch: </div></body></html>