Question 1
AIM: To determine the forward current voltage characteristics of Zener diode.
- Connect the circuit diagram as shown in Figure 1.
- Ask the Supervisor to check the circuit connection.
- You are provided with Table 1.
Table 1
VS (V) |
VD (V) |
ID (mA) |
0.0 |
|
|
0.5 |
|
|
0.8 |
|
|
1.0 |
|
|
2.0 |
|
|
5.0 |
|
|
8.0 |
|
|
10.0 |
|
|
- Switch on the power supply unit.
- Set the input d.c. of the power supply unit to 0 V.
- Read and record the ammeter and voltmeter readings in Table 1
- Set the input d.c. of the power supply unit to 0.5 V.
- Read and record the ammeter and voltmeter readings.
- Repeat steps (g) and (h) for the other corresponding values of VS in Table 1.
- Switch off the power supply unit.
- Plot a graph of current I (mA) on the vertical axis against voltage VD (V) on the horizontal axis.
- From the graph, determine the knee voltage of the diode.
Observation
The expected responses were:
TABLE 1
VS (V) |
VD (V) |
ID (mA) |
0.0 |
0.0 |
0.0 |
0.5 |
0.2 - 0.5 |
0.2 – 0.3 |
0.8 |
0.3 – 0.7 |
0.5 – 1.0 |
1.0 |
0.3 – 0.7 |
1.0 – 1.5 |
2.0 |
0.3 – 1.1 |
2.5 – 7.5 |
5.0 |
0.4 – 1.1 |
8.5 – 10.5 |
8.0 |
0.4 – 1.1 |
14.0 – 18.0 |
10.0 |
0.4 – 1.1 |
18.0 – 22.0 |
(k) A non-linear curve from origin (0, 0) in the positive space.
(l) knee voltage of 0.3 – 0.7 V.