Consider a linear potentiometer as shown in Figure 12.1. The potentiometer consists of 0.1-mm copper wire (re = 1:7 ×10^-8 V-m) wrapped around a core to form a total resistance of 1 kV. The sliding contact surface area is very small.

a. Estimate the range of displacement that could be measured with this potentiometer for a 1.5-cm core.

b. The circuit shown in Figure 12.63 is used to record position. On a single plot, show the loading error in an indicated displacement as a function of displacement, over the range found in (a), for values of the meter resistance, Rm, of 1, 10, and 100 kW. For practical meters, would the loading error be significant?

 

Transcribed Image Text:

Core Winding Wiper Adjustable position E, RE, Figure 12.63 Circuit for Problem 12.1. w- Core Winding Wiper Adjustable position E, RE, Figure 12.63 Circuit for Problem 12.1. w-