Rectificador de onda completa (puente de diodos)

Introduction to Full Wave Rectifier with Bridge Configuration

In this section, we will learn about the full wave rectifier with bridge configuration. This configuration uses four diodes instead of a transformer and two diodes like in the previous rectifier.

Full Wave Rectifier with Bridge Configuration

• The full wave rectifier with bridge configuration eliminates the need for a transformer and uses four diodes.

• The circuit consists of a source, fuse, and four diodes arranged in a bridge configuration.

• The positive half-cycle of the AC input is converted into a positive output voltage at the load resistor.

• The negative half-cycle of the AC input is converted into a negative output voltage at the load resistor.

Configuration and Analysis

In this section, we will analyze the configuration of the full wave rectifier with bridge configuration and understand its operation.

Configuration

• The source, fuse, and transformer remain unchanged in this configuration.

• There is no center tap present in this configuration.

• The four diodes are connected in a bridge arrangement using 1A to 4A connections.

• A load resistor is connected to obtain the desired output voltage.

Analysis of Positive Half-Cycle

In this section, we will focus on analyzing the positive half-cycle of the AC input in the full wave rectifier with bridge configuration.

Positive Half-Cycle Analysis

• During the positive half-cycle, the AC source provides a positive polarity at its terminals.

• This polarity is transferred to both ends of the primary winding of the transformer.

• As a result, there is no voltage reduction or increase across the transformer. It remains 1:1 ratio.

• The positive potential pushes the current towards the black node in the circuit, allowing only one diode to be forward biased.

• The current flows through that diode and the load resistor, resulting in a positive voltage across the load resistor.

• The voltage waveform at the output terminals of the rectifier shows a positive half-cycle.

Analysis of Negative Half-Cycle

In this section, we will analyze the negative half-cycle of the AC input in the full wave rectifier with bridge configuration.

Negative Half-Cycle Analysis

• During the negative half-cycle, the polarity of the AC source is reversed.

• This reversed polarity is transferred to both ends of the primary winding of the transformer.

• As a result, there is no voltage reduction or increase across the transformer. It remains 1:1 ratio.

• The current now flows through a different path due to changed polarities, but still passes through the load resistor.

• The voltage waveform at the output terminals of the rectifier shows a negative half-cycle.

Output Voltage Waveform

In this section, we will understand how both positive and negative half-cycles combine to form an output voltage waveform.

Output Voltage Waveform

• The combination of positive and negative half-cycles results in an output voltage waveform with both positive and negative cycles.

• The load resistor receives a positive half-cycle during one direction of current flow and a negative half-cycle during another direction of current flow.

• There is no reduction in amplitude or frequency as there is no voltage transformation after passing through the load resistor.

Polarities Reversed for Negative Half-Cycle

In this section, we will discuss how polarities are reversed for each half-cycle in full wave rectifier with bridge configuration.

Polarities Reversed for Negative Half-Cycle

• For the negative half-cycle, the polarities of the AC source, primary winding of the transformer, and secondary winding are reversed.

• This reversal causes a change in current flow direction through the diodes and load resistor.

• The output voltage waveform shows a negative half-cycle due to this polarity reversal.

Parameters in Full Wave Rectifier

In this section, we will discuss important parameters in the full wave rectifier with bridge configuration.

Parameters in Full Wave Rectifier

• The key parameters to consider are peak output voltage at the load resistor and reverse voltage across diodes during non-conducting periods.

• The peak output voltage is measured at the load resistor and depends on both positive and negative half-cycles.

• During non-conducting periods, two diodes remain reverse biased.

Conclusion

The full wave rectifier with bridge configuration eliminates the need for a transformer and uses four diodes to convert both positive and negative half-cycles of an AC input into a DC output. The analysis of each half-cycle reveals how current flows through different paths to produce an output voltage waveform. Important parameters such as peak output voltage and reverse voltage across diodes should be considered when designing or analyzing a full wave rectifier.

New Section

This section discusses the potential difference and voltage measurements in a circuit with diodes.

Potential Difference and Voltage Measurements

• The potential positive point in the circuit represents the point where the diode is activated in forward bias.

• The potential at this point corresponds to the positive potential.

• The other end of the resistor represents the output peak voltage measurement point.

• This point is connected to ground and represents one terminal of the transformer.

• The voltage measured at this point is equal to the peak voltage of the secondary side when using ideal diodes.

• However, if real diodes are used, there will be a voltage drop across different points in the circuit that needs to be considered.

New Section

This section explains how voltage measurements change when using ideal or real diodes.

Voltage Measurements with Ideal and Real Diodes

• In a circuit with ideal diodes, during the positive half cycle, one terminal represents the top terminal of LEDs and is connected to ground.

• In an inverse bias configuration, this terminal represents the negative terminal connected to ground.

• The output peak voltage seen by the load is equal to the peak voltage of the secondary side when using ideal diodes.

• However, if real diodes are used, there will be different voltages between terminals due to reverse biasing.

• The reverse bias voltage can be measured between each diode's cathode terminal and ground.

New Section

This section explores how voltage measurements change when using practical or real diodes.

Voltage Measurements with Practical Diodes

• When using practical or real diodes, it becomes difficult to determine which node corresponds to which in terms of voltages.

• There will be a reverse peak voltage between terminals for each reverse-biased diode.

• By following the circuit path, it can be observed that after passing through certain points, a forward bias voltage appears.

• The circuit is closed when reaching a specific point, denoted as "sub 2".

• In a direct bias configuration, the sum of voltages between two points corresponds to the reverse peak voltage.

New Section

This section discusses the voltage measurements in a bridge rectifier circuit using practical diodes.

Voltage Measurements in Bridge Rectifier Circuit

• In a bridge rectifier circuit with practical diodes, the output peak voltage plus the drop across diode junctions will appear across terminals 7 and 4.

• The voltage measured between these two points corresponds to the reverse peak voltage.

• The sum of voltages between terminals 7 and 4 represents the total forward bias voltage when using ideal diodes.