LOTO Lesson 2: Diode Practice--- Bridge Full-wave Rectification

LOTO2018

LOTO Lesson 2: Diode Practice--- Bridge Full-wave Rectification [Copy link]

Resources used in practice

4 rectifier diodes, 500R resistor (as load), oscilloscope, signal source

Note: The resistance value does not need to be accurate. This resistor is used as a load. The resistance value cannot be too large. If it is too large, the current will be limited to a very small value, which may cause the rectifier diode to cut off. Pay attention to the polarity when welding the diode. The signal source must be able to generate a sinusoidal AC signal with a frequency of 50HZ and a positive or negative 2V or more.

The video uses the built-in signal source module of OSC482S to generate a positive and negative 2V sine wave as the input of the diode bridge circuit. The two channels of the oscilloscope are used to detect the terminal voltage of the output end respectively, and the channels are subtracted to display the rectified waveform added to both ends of the load. In order to clearly see the rectification result, we did not add a filter capacitor in the video. Once the capacitor is added, the output becomes DC. You can try it yourself.

Video link: https://www.bilibili.com/video/BV1xA411b7A2
Questions to think about after practice: Why does the input signal need to be greater than about ±2V? Why doesn't the video directly measure the voltage waveform between the two ends of the load, AB, but instead measures the voltage waveforms at points A and B separately and then subtracts the channels to obtain the complex voltage waveform between AB?