1. Full-wave bridge rectifier with a capacitor filter
Plug in the AC power plug which is connected to the transformer primary winding
into an AC power 220 VRMS outlet, turn on the switch and measure the transformer secondary
AC voltage using both multi-meter and oscilloscope. Compare the measured results.
Construct the circuit shown in Figure 1, with a 100 µF 50V electrolytic capacitor as a
filter. Connect a load resistor R = 100 Ω 5W across the filter capacitor. Use oscilloscope to
display voltage waveforms at the input of the bridge diode and at the load resistor. Record the
waveforms at the bridge diode input and load resistor.
Remove the 100 µF capacitor, and record the waveforms at the bridge diode input and
load resistor again.
Connect a 1 µF 50V capacitor as a filter across the load resistor, and record the
waveforms at the bridge diode input and load resistor again.
2. 3-terminal IC voltage regulator
Construct the circuit shown in Figure 4, with a 100 µF 50V electrolytic capacitor as
an input filter and a 1 µF 25V electrolytic capacitor as an output filter. Move the load resistor
R = 100 Ω 5W to connect to the IC 7812 output. Connect the output of the bridge diode
(unregulated DC voltage) to the IC 7812 input. Use oscilloscope to display voltage
waveforms at the input of the IC 7812 and at the load resistor. Record the waveforms at the
IC 7812 input and load resistor.
Use a multi-meter to measure the voltage difference between the input and output of
the IC 7812 voltage regulator. Calculate for the load current