<p> ET 332a Lab 11 Voltage Build-up Factors in Self-Excited Generators Revised Data Table and Procedure</p><p>Field Resistance Generator Voltage (Ea) Rheostat Load Box Field Current Field Resistance Decreasing Increasing </p><p>(A) If () Rf Field R Field R max all off 0 A infinite min all off 0 A infinite min 2 on min 4 on min 6 on min 8 on min 10 on min 12 on min 14 on min 16 on</p><p>Procedure</p><p>1.) Before connecting the load box to the generator circuit, measure the box's resistance for all the switch positions listed in the table above using a multimeter. Record these values in the Field Resistance (Rf) column 2.) Take the measurements of If and Ea for each load box setting for both decreasing and increasing values of field circuit resistance. 3.) Graph the average Ea for the increasing and decreasing generator voltage columns against the field current, If. (x-axis=If y-axis= average Ea) 4.) Measure the field coil resistance, Rc, without the load box connected in series. Record this value for the report. 5.) For the "8 on" entry of field resistance, plot the field resistance line with the following two points (0,0) and If=.5A, Ea=(Rf +Rc)(.5A). This line should be plotted on the same axis at the data from 3 above. </p><p>Fall 2002 lab10br.doc</p>