Electrical circuits – Texas Instruments TI-86 User Manual

Page 260

248

Chapter 19: Applications

19APPS.DOC TI-86, Chap 19, US English Bob Fedorisko Revised: 02/13/01 2:41 PM Printed: 02/13/01 3:05 PM Page 248 of 18

Electrical Circuits

A measurement device has measured the DC current (C) in milliamperes and voltage (V) in
volts on an unknown circuit. From these measurements, you can calculate power (P) in
milliwatts using the equation

CV=P

. What is the average of the measured power?

With the TI

-86, you can estimate the power in milliwatts at a current of 125 milliamperes

using the trace cursor, the interpolate

àextrapolate editor, and a regression forecast.

ᕡ In two consecutive columns of the list editor, store the current

measurements shown below to the list name

CURR

and the

voltage measurements shown below to the list name

VOLT

{10,20,40,60,80,100,120,140,160}¶CURR

{2,4.2,10,18,32.8,56,73.2,98,136}¶VOLT

ᕢ In the next column of the list editor, enter the list name

POWER

ᕣ Enter the formula

CURR

VOLT

in the list editor entry line for

POWER

. Press b to calculate the values for power and store

the answers to the list name

POWER

ᕤ Select

WIND

from the

GRAPH

menu and set the window variable values as shown.

xMin=0

xMax=max(POWER) xScl=1000

yMin= 0

yMax=max(CURR) yScl=10

xRes=4

ᕥ From the home screen, select

FnOff

from the

CATALOG

and

press b to deselect all functions in the equation editor.
Select

Plot1(

from the

CATALOG

and set up a stat plot with

POWER

on the x-axis and

CURR

on the y-axis.