Diode Characteristic and Application EXPERIMENT 6 Diode Characteristic and Application

Forward-bias Diode Characteristics PART A Forward-bias Diode Characteristics

Silicon Diode (D1N4002) Germanium Diode (1N34A)

Construct the circuit as is shown in Fig. 6.1 using a Si diode. B C A D

Repeat step 2 for the remaining settings of VD shown in the Table 6.1. By varying the DC Supply voltage, set the diode voltage VD = 0 V and measure diode current ID and record the result in Table 6.1 Now, set the diode voltage VD = 0.1V. Measure the corresponding diode current ID and record the result in Table 6.1 Repeat step 2 for the remaining settings of VD shown in the Table 6.1. Table 6.1 VD (V) 0.1 0.2 0.3 0.4 0.5 0.6 0.65 0.7 ID (A)  0 0  5.45 A  40 A 0.29 mA   1.7 mA  4.35 mA  9.21 mA 

Replace the Si diode by a Ge diode and complete Table 6.2. Plot ID versus VD characteristics curves on a graph paper for both silicon and germanium diodes. Table 6.2 VD (V) 0.1 0.2 0.3 0.4 0.43 0.6 0.7 0.75 ID  0 0  81 A   1.175 mA  6.92 mA  9.47 mA  

Conclusion: You should notice that the turn on voltage for Ge diode is smaller than the silicon diode, which makes it more efficient.

Half Wave Rectification PART B Half Wave Rectification

Construct the circuit of Fig. 6. 2 Construct the circuit of Fig. 6.2. Set the supply to 9 V p-p sinusoidal wave with the frequency of 2 kHz. Put the oscilloscope probes at function generator and sketch the input waveform obtained.

Put the oscilloscope probes across the resistor and sketch the output waveform obtained. Measure and record the DC level of the output voltage using the DMM. +Vsine GND A B D1N4002 2.2 k OSCILLOSCOPE + - OSCILLOSCOPE + -

Reverse the diode of circuit of Fig. 6. 2 Reverse the diode of circuit of Fig. 6.2. Sketch the output waveform across the resistor. Measure and record the DC level of the output voltage.