Purpose:Illustrate resistive properties of resistors and diodes.
Description:A signal generator set to 500 Hz is used as the source of AC current feeding a series circuit with a shunt resistor and one other "test" circuit component, which can be either a resistor or a diode. The current is displayed on the vertical axis of the oscilloscope as the voltage across a shunt resistor. The voltage across the second element (the element under study) is displayed on the horizontal axis. As seen in the photograph above, the diode is non-ohmic. The breakdown potential of the diode can be observed.
The polarity of the vertical input must be inverted in this demonstration due to grounding of the point between the two circuit elements.