Oscilloscope Patterns and Waveforms

WAVE PATTERN CHECK USING AN OSCILLOSCOPE

Standard Waveform:

MEASUREMENT METHOD
Connect an oscilloscope probe to the generator "B" terminal.





















NOTE: The voltage wave form of the generator B terminal can undulate as shown at left. This wave form is produced when the regulator operates according to fluctuations in the generator load (current), and is normal for the generator If the ripple height is abnormally high (approximately 2 V or more during idling), the wires between the generator B terminal and the battery have broken due to fuse blowing, etc. The generator is usually operating properly.

ABNORMAL WAVE FORMS EXAMPLES

NOTE: The size of the wave form patterns can differ greatly depending on the adjustment of the variable knob on an oscilloscope.

NOTE: Identification of abnormal wave forms is easier when there is a large output current (regulator is not operating). (Wave forms can be observed when the headlights are illuminated.)

NOTE: Check the conditions of the charging indicator light (illuminated/not illuminated) also, and carry out a total check.