Bấm vào tùy chọn Custom, và bằng cách sử dụng nút khối chọn trên bên phải của hộp nhập dữ liệu trực quan có thể chặn các dữ liệu cho cả hai bên tích cực và tiêu cực của thanh lỗi. Bây giờ bất cứ khi nào các giá trị đo được là ở bên ngoài giá trị lý thuyết, nó có thể nhìn thấy trên biểu đồ. Các thanh lỗi có thể nhìn thấy trong hình | Example 1 Voltage-to-Current Converter Click on the Custom option and using the block select button on the right of the data entry box we can visually block the data for both the positive and negative sides of the error bar. Now whenever the measured value is outside the theoretical value it is visible on the chart. The error bars are visible in Figure 1-22. Adding a Trendline Excel has the capability of generating a regression on a line and determining the best form of the equation. Right-click on the Output Current line and select Add Trendline from the menu as shown in Figure 1-19. V to I Converter Figure 1-20 Defining the type of regression. JU o Input Voltage V Figure 1-19 Initiating a trendline. T íẫ Format Data Series. Chart Type. Source Data. Add Trendline. Clear Figure 1-20 shows the dialog that appears. Select a linear regression and then click on the Options tab. 21 Excel by Example Under the options Figure 1-21 ensure the Display equation on chart is selected and click on OK. Figure 1-21 Adding the equation to the chart. The trendline and the equation for it are added to the chart as shown in Figure 1-22. V to I Converter Figure 1-22 Trendline and associated equation. - Output Current Theoretical Current Linear Output Current Input Voltage V Macro Timer In many circuits especially where a current is being generated the output requires some time to stabilize. Why not use the computer to time this period and notify us when it is time for the next measurement 22 Example 1 Voltage-to-Current Converter In order to do this we need to use a macro. I will go into this in greater depth later in the book. For the moment just follow along to see the effect. In order to use this feature we will need to have installed certain add-in modules as described in the front of this book. Navigate the menus Tools Macros Visual Basic Editor. We should arrive at a screen resembling Figure 1-23. Figure 1-23 Startup Visual .
