Agilent Viewing Graphical Results on a DMM Display - Application Note 5991-2226EN c20140723 [6] free download

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Keysight Technologies Viewing Graphical Results on a DMM Display Application Note Introduction Digital multimeters measure and display various parameters such as voltage, current, resistance, and temperature in an easy-to-read number format. However, many times you are looking for more than a single reading in the display. Often, the really meaningful information lies in the trend or statistics of a series of readings. If your DMM offers connectivity, such as LAN or USB ports, you can transfer your readings to a computer for computation and display. But transferring data to a PC may take more time than you want to spend. Now, a new DMM, the Keysight Technologies, Inc. 34461A, offers a way to get insight into your measurement data without transferring your data to a PC. The 34461A features a large graphical display and built-in math functions that show measurement trends, statistics, and histograms all in a single, compact unit. Snapshot A company designing a high-power solar charger for smart phones and tablets needed to rigorously test the circuit that detected low solar-cell power for shutting down and restarting the charging circuit smoothly. This circuit was necessary because the charger had no internal battery to act as a buffer. To simulate changing solar radiation, the design team used a triangle waveform from an arb/function generator as a source. The engineers set up the Keysight 34461A to measure the on/off output voltage of the detector circuit and displayed the results using the histogram mode. At frequencies below one Hertz, the display clearly showed a binary distribution, which was the desired result. However, they found that for higher frequencies, which occurred when they waved a hand across the solar panel, the circuit exhibited an anomaly that caused an intermediate output value. This anomaly clearly interfered with the proper output charging operation. A relatively simple design change to the cutoff frequency in the detector circuit solved the problem and eliminated potential customer warranty claims. 03 | Keysight | Viewing Graphical Results on a DMM Display