Electronics: Principles and Applications Eighth Edition (Instrumentation Labs) Charles A. Schuler Lab 1 Introduction to the Function Generator and DMM McGraw-Hill ©2013 by The McGraw-Hill Companies, Inc. All rights reserved

A generator provides its calibrated output voltage when RL = RI. VRMS RL RI 20 VPP 10 VPP RI = 50  VRMS = 0.707 VPP 2 = 3.535 V For a sine wave:

The open-circuit (unloaded) voltage is higher. The DMM’s resistance (RM) is very high and the generator is essentially unloaded. RM = 10 M 20 VPP 20 VPP (7.07 VRMS)

Measuring the dc voltage drop across RB RA RC VOLTMETERS ARE CONNECTED IN PARALLEL.

This DMM has auto polarity. RB RA RC

Measuring the current through RC 3 3. Select DC I 1 1. Use I jack 2 2. Press Shift RA 4. Break the circuit RC RB AMMETERS ARE CONNECTED IN SERIES.

W Measuring resistance RA RC RC RB DO NOT MEASURE RESISTANCE IN LIVE CIRCUITS!

Function generator and DMM Quiz A calibrated signal generator will produce an output equal to its amplitude setting only when the load is equal to RI The open-circuit output amplitude is always ___________ than the amplitude setting. greater than Voltmeters are connected in parallel Ammeters are connected in series Ohmmeters are never connected to live circuits