Diode V–I characteristics

Procedure

1. Check the device marking and datasheet to identify its anode and cathode.
2. Switch the supply off. Connect the diode, limiting resistor, and current meter in series, with the voltmeter across the diode.
3. For forward bias, point the anode toward the positive supply. Raise the voltage in small steps within the device’s ratings.
4. At each step, note the diode voltage and current. Take smaller steps where the current begins to rise steeply.
5. Turn the supply off before reversing the diode. Under supervision, take reverse-bias readings below breakdown and plot both sets.

Precautions

1. Include a current-limiting resistor every time and observe the diode’s and meters’ ratings.
2. Disconnect the supply before rewiring. Keep reverse-bias measurements below breakdown.