Tektronix TCP300A, User Manual

Page: 54 / 82

Application Notes
Figure 19: Setup for measuring charging current
The waveform (a) shows the three-phase ripple frequency. (See Figure 20.)
The average charge current is approximately 27 A with a minimum peak of
approximately 23 A and a maximum peak of approximately 31 A. The waveform
shows a continuous cycle with no dropouts, so the alternator circuit appears to be
functioning properly. A single-phase diode failure normally appears as an extreme
drop in charge current every third cycle, waveform (b). (See Figure 20.)
Figure 20: Charge current waveforms
36 TCPA300/400 Ampli fi ers and TCP300A/400 Series Current Probes User Manual