What is a precision rectifier circuit?What are the four steps of a rectifier circuit?
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# What is a precision rectifier circuit?What are the four steps of a rectifier circuit?

Posted Date: 2024-01-13

What is a precision rectifier circuit?

Before understanding the precision rectified current source, let's recall the basics of rectifier circuits. Regarding the rectifier circuit, I have explained it in detail in an article before. If you don’t remember, you can search on my homepage.

The figure below shows the characteristics of an ideal rectifier circuit and its transfer characteristics, which means when the input signal is positive, the output will be 0 V and when the input signal is positive, the output will follow the input signal.

Characteristics of ideal rectifier circuit and its transfer characteristics

The figure below shows a practical rectifier circuit and its transmission characteristics. In the actual rectifier circuit, the output waveform will be 0.7V smaller than the actual input voltage, and the transmission characteristics will be as shown in the figure below. At this time, the diode will conduct as long as the applied input signal is slightly greater than the forward voltage of the diode.

Practical rectifier circuits and their transmission characteristics

What are the four steps of a rectifier circuit?

The four steps of the rectifier circuit are as follows:

1. Copy: The rectifier circuit first copies the input AC signal. The purpose of duplication is to allow the rectifier circuit to process the positive and negative half-cycles of the input signal at the same time.

2. Rectification: In the rectification step, the positive or negative half cycle of the AC signal is converted into a unidirectional signal. This is usually achieved by using components such as diodes, bridge rectifiers or thyristors.

- Single-phase half-wave rectification: In a single-phase half-wave rectification circuit, only the positive or negative half-cycle of the input AC signal is rectified.

- Single-phase full-wave rectification: In a single-phase full-wave rectification circuit, both the positive and negative half-cycles of the input AC signal are rectified.

- Three-phase rectification: In a three-phase rectification circuit, the AC signals of all three phases are rectified.

3. Filtering: The rectified signal will contain certain ripples or pulsations, and the filtering step is designed to reduce or remove these ripples. Filtering is usually done using capacitors, inductors, or a combination thereof. Filtering can make the output signal closer to a smooth DC signal.

4. Voltage stabilization: The final step is to use a voltage stabilization circuit to maintain the stability of the output signal. The voltage stabilizing circuit can adjust to changing loads and input power fluctuations to ensure that the output DC voltage or current remains within a predetermined range.

These four steps allow the rectifier circuit to convert AC signals into DC signals and ensure that the output DC voltage or current meets the required stability and accuracy requirements.

How does a rectifier circuit rectify?

A rectifier circuit is a circuit that converts an alternating current signal into a unidirectional direct current signal. One of the main components of the rectifier circuit is the diode, which is the key to achieving rectification in the rectifier circuit.

When the diode is in the conducting state, current can flow from its anode to the cathode; when the diode is in the off state, current is not allowed to flow from the anode to the cathode.

In a single-phase half-wave rectifier circuit, when the diode is in the conducting state, only the positive half cycle of the input signal is rectified, and the negative half cycle is cut off. In this way, the load resistor in the rectifier circuit obtains electric energy during the positive half cycle, and is not affected by the surrounding input signal during the negative half cycle.

In a single-phase full-wave rectifier circuit, a bridge rectifier can be used to rectify both the positive and negative half-cycles of the input signal. The bridge rectifier consists of four diodes, which convert both the negative half cycle and the positive half cycle of the input signal into a unidirectional current. The DC signal is filtered by using a filter capacitor to produce a more stable DC voltage output.

In a three-phase rectifier circuit, six diodes rectify the positive half-cycle and negative half-cycle of each phase to generate a DC signal. The DC signal is then filtered through the filter capacitor to produce a more stable DC voltage output.

The rectifier circuit obtains a DC signal by passing the AC signal through components such as diodes or bridge rectifiers to achieve unidirectional current. In order to produce a more stable DC output, the rectifier circuit needs to be filtered using filter capacitors.

Characteristics and applications of precision rectifier circuits

Precision rectifier circuit is a circuit used to convert AC signals into high-precision DC signals. It has the following characteristics:

1. High precision: Precision rectifier circuit can provide high-precision DC output. It usually uses high-precision components and technology to ensure the stability and accuracy of the output DC voltage or current.

2. Low ripple: Precision rectifier circuits can effectively reduce the ripple of the output signal by using filter capacitors and other filtering techniques. This provides a more stable, low-noise DC output signal.

3. Wide bandwidth: Precision rectifier circuits are usually designed with wide bandwidth characteristics, allowing them to process a wide range of frequency signals.

4. Temperature stability: Precision rectifier circuit can maintain high stability under different temperature conditions. This is very important for applications that require stable DC output under different ambient temperatures.

5. High efficiency: Precision rectifier circuits usually adopt high-efficiency designs to provide higher conversion efficiency and reduce power consumption.

Precision rectifier circuits are widely used, including but not limited to the following fields:

1. Measuring and testing equipment: In the field of precision measurement and testing, high-precision and stable DC signals are required to drive sensors, instruments and measuring equipment.

2. Communication equipment: Precision rectifier circuits can be used in communication equipment to provide stable DC power to drive radio frequency amplifiers, filters, baseband equipment, etc.

3. Medical equipment: In medical equipment, high-precision DC power is required to supply precision instruments, sensors, laser equipment, etc.

4. Industrial automation: In industrial automation systems, precise DC power is required to provide precision controllers, sensors, drivers and other equipment.

Precision rectifier circuits are widely used in fields that require high-precision, stable and low-noise DC signals. They provide high-quality power that meets a variety of requirements for high accuracy and low ripple.

Review Editor: Huang Fei

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