4. Circuits with diodes¶
The components available for experimenting with diodes are:
1 Zener 5.1V
Resistors of 1kΩ and 10kΩ
Capacitors of 1uF, 10uF and 0.1uF
4.1. Diode characteristic curve¶
The VISIR remote laboratory can be used to obtain the diode characteristic curve. In this experience it can be verified what it happens when the diode is polarized in direct and in reverse. For that:
Carry out the following assembly
Set the supply voltage. Use the + 25VDC source.
Measure the voltage drop on the diode
Implementation on the remote laboratory:
In this circuit it is also possible to measure the current flowing through the diode. To do this, connect the multimeter between the diode and the resistor or before the diode.
4.2. Half-wave rectifier¶
If, in the previous circuit, the DC source is replaced by the function generator and the circuit is supplied with a sinusoidal signal, we can observe the operation as a half-wave rectifier.
In the circuit above, the diode can be connected in direct or inverse and observe how the diode rectifies the positive or negative half-cycle of the input signal in each case.
4.3. Half-wave rectifier with output filter¶
A low-pass filter can be added to the previous circuit at the output to obtain a continuous signal. To do this, simply add a capacitor in parallel to the 1kΩ resistor. The available capacitor values are 1uF, 10uF and 0.1uF.
4.4. Zener diode voltage regulator¶
Through this experiment the operation of a Zener diode can be analysed, either with forward or reverse polarization. For this, the remote laboratory has a 5.1V Zener diode, a 470Ohms resistor and a 1k resistor, which can be connected to the conFiguretion shown at Figure 11, in which the diode can be removed and see how it affects the voltage drop between both resistors.
In the previous circuit it is also possible to connect the multimeter before the 470 ohms resistor and in front of the Zener diode to obtain its characteristic I-V curve varying the value of the supply voltage VDC and taking measures of voltage and intensity on the circuit.
That’s all in Circuits with Diodes. Continue in RC Circuits.