LM1875 20 Watt Audio Power Amplifier

The amplifier circuit can be constructed using the LM1875 power amplifier IC. The LM1875 is a single-chip power amplifier from National Semiconductor. This 20-watt audio amplifier is characterized by low power consumption while delivering high-quality sound suitable for use in a room setting. Assembling the 20-watt amplifier with the LM1875 requires minimal additional components. The circuit utilizes a symmetrical power supply. The 20-watt audio power amplifier using the LM1875 can serve as a practical experiment or introductory project for readers due to its simplicity and high likelihood of successful assembly. The LM1875 amplifier circuit can achieve a voltage gain of up to 27 dB for each channel (one IC per channel). The voltage gain can be adjusted by modifying the feedback resistor (R5) in the circuit; the configuration presented uses a 22kΩ resistor. However, the voltage gain should not be set below 20 dB, as this may lead to oscillation. For powering the 20-watt amplifier circuit with the LM1875, a transformer rated at 2-3A with a center-tapped output can be used.

The LM1875 power amplifier IC is designed to provide efficient amplification of audio signals, making it suitable for various applications, including home audio systems and small public address systems. The circuit typically requires a symmetrical power supply to ensure balanced operation, which can be achieved using a center-tapped transformer. The output power of 20 watts is sufficient for driving moderate-sized speakers, making it ideal for casual listening environments.

The gain of the amplifier can be fine-tuned by selecting different resistor values in the feedback loop. The recommended feedback resistor value of 22kΩ allows for a stable gain of 27 dB, which is well within the operational parameters of the LM1875. It is crucial to maintain the gain above 20 dB to avoid potential stability issues, such as oscillation, which can degrade audio performance.

The LM1875 is also designed with thermal protection features, which help prevent damage due to overheating during prolonged operation. Proper heat dissipation should be ensured by using an adequate heatsink, especially when the amplifier is driven close to its maximum output power.

In summary, the LM1875 amplifier circuit is a straightforward and effective solution for audio amplification needs, offering a good balance of power, quality, and ease of assembly. Its design flexibility allows for adjustments in gain and output characteristics, making it suitable for a wide range of audio applications.The Amplifier circuit can be made with an IC power amplifier LM1875. IC LM1875 is a single chip power amplifier from National. 20 watts audio amplifier with LM1875 is a low power amplifier with good quality to the room. To assemble the amplifier 20 watts with IC LM1875 component is not needed much support. 20 watts power amplifier using LM1875 IC in this article using symmetrical power supply. The series of 20 watts audio power amplifier with IC LM1875 can be used as an experiment or first project for the reader, because it is simple and assembly of high success. LM1875 amplifier circuit with the above may result in the strengthening of the voltage up to 27dB for each channel (1 channel 1 IC).

Strengthening the voltage can be changed by changing the feedback that is R5 R (on the circuit above using R 22K). But the tension reinforcement can not be less than 20 dB because it can cause oscillation. For the power supply or power supply 20 watts power amplifier rngakaian with lm1875 can use travo 2-3A with CT.

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