Output power

Related concepts

Introduction

1. The rated power of the speaker is also called the nominal power, which means that the speaker is allowed to input the speaker under the condition of the rated distortion The maximum electric power. Its unit is vA (volt-ampere) or liner (watt).

2. Nominal power refers to the maximum output power of the speaker for a long time without distortion, and the maximum power refers to the maximum instantaneous power of the speaker without damaging the speaker. The maximum load capacity that can be withstood.

Accurate definition

The definition of output power is the energy provided to the outside world by energy or equipment per unit time. There is no specific calculation formula for the output power, unless the mechanical work done by the motor per unit time is measured. Because a considerable part of the input power is converted into electromagnetic waves or mechanical friction loss is also related to the phase difference of AC voltage and current.

Introduction to output power

Amplifier output power

Strictly speaking, the power index of a power amplifier is divided into nominal output power and maximum instantaneous output power. The former is the rated output power, which can be interpreted as the maximum value of the output power when the harmonic distortion changes within the standard range and can work safely for a long time; the latter refers to the "peak" output power of the power amplifier, which is interpreted as the power amplifier accepts When an electrical signal is input, the maximum output power that can be withstood instantaneously under the premise of ensuring that the signal is not damaged.

Mechanical output power

is the ratio of the energy output from various energy sources or energy conversion equipment (such as power and lighting equipment) to time, that is, the energy or equipment direction per unit time The energy provided by the outside world. Its units are generally watts and kilowatts, and are often expressed in volt-ampere and kilovolt-ampere in power systems.

However, it should be noted that many hosts on the market are marked with their peak power. We need to discount this number by 50% before the actual output power can represent this host. Load capacity.

Speaker output power

The speaker output power refers to the maximum power that the home theater set can produce.

The sound quality is not directly related to power. The power determines the maximum sound intensity that the speaker can emit, and it feels like how powerful the sound of the speaker can be.

According to international standards, there are two labeling methods for power: rated power (RMS: sine wave root mean square) and instantaneous peak power (PMPO power). The former refers to the maximum electric power that drives an 8Ω speaker within the rated range and specifies the waveform continuous analog signal, after a certain interval and repeats a certain number of times, the speaker does not cause any damage; the latter refers to the maximum power that the speaker can withstand in a short time . The United States Federal Trade Commission stipulated the power calibration standard in 1974: The effective wattage measured when the harmonic distortion is less than 1% in the range of 20 to 20000 Hz is the effective wattage measured when driving an 8Ω speaker load with two channels. For output power, the marked power is the rated output power. In order to cater to consumers' psychology, merchants usually mark the instantaneous (peak) power, which is generally about 8 times the rated power. Therefore, the rated power shall prevail when purchasing a home theater package.

The power of the speaker is not the bigger the better, and the application is the best. For ordinary household users in a room of about 20 square meters, the real power of 60W (refers to the effective output power of the speaker 30W x 2 ) Is enough, but the larger the reserve power of the power amplifier, the better, and it is better to be more than 2 times the actual output power. For example, if the speaker output is 30W, the power amplifier capacity should be greater than 60W. For the HiFi system, the power amplifier power driving the speaker is very large.

Motor output power

The input power of the motor is defined as: the voltage across the motor multiplied by the current flowing through the motor. It does not mean that the output power is true. The output power is the power value that the motor converts electrical energy into mechanical energy. Since the current motors are not ideal, in normal work due to the actual coil resistance, shaft friction and other factors, a small part of the electrical energy will be converted into other forms of energy (mainly thermal energy) and lost, so The output power is less than the input power. And the greater the power of the motor, the smaller the difference between the two, and the smaller the power, the greater the difference.

Maximum output power

Maximum output power refers to the power amplifier within a certain harmonic distortion index (for MP3, MP4 and other electronic products, the most common application is headphones) When a large enough signal is input and the volume and tone potentiometers are adjusted to the maximum, the maximum power that the power amplifier can output is called the maximum output power. Currently, the maximum output power of MP3 on the market is generally 10mW, 20mW, 40mW, etc.