Why do some power amplifiers have a lot of power transistors in them?

BTL power amplifier, a channel to use 4 high-power transistors, because the even harmonic distortion of BTL power amplifier cancels, the sound is not good, so it is rarely used in the family. (In car audio, due to the low working voltage, all this).

In the home power amplifier, the performance of the P-type and N-type is also symmetrical, and the maximum collector current is about 15A, but the linearity of the tube is very poor at this time (the magnification is not linear).

Through the I-V curve of the ** tube, it can be found that when the maximum collector current is below 30%, the linearity is better, so the 15A tube can only be used about that, which is the peak of the sine wave, and can only get about 40W of power in a 4 ohm speaker.

In order to pursue a sense of scene, such as the insect cry in a quiet garden, some ** only output 1 to 2w of power at this time, and ** aircraft take off, ** scene, often need to output more than 100w of power.

In this case, the amplifier needs to have a larger linear current output capability to reduce the distortion ......Therefore, many good power amplifiers even take 4 pairs of power tubes in parallel output, at this time, the output of 18A current, the power amplifier will not produce additional, small distortion.

You can understand that the more power tubes, the more power, which is basically the case in ballrooms, but the sound quality is not necessarily very good.

The two-way push-pull type uses 4 tubes, and each tube uses a buffer tube, not counting the preamp, the output needs 8 tubes, and a large radiator is used. For less demanding amplifiers, a power amplifier tube is sufficient. Different output forms and different power levels lead to different tube dosages.

The main differences are as follows:

1.The principle is different:

In principle, the bipolar semiconductor trio is the characteristic that the input current controls the output current, or the input voltage of the field-effect semiconductor triode controls the output current to realize the amplification of the signal. In principle, the power tube simply acts as a dual network and then outputs voltage.

2.The use of the function is different:

The use of power is to convert the energy of the power supply into the required form of energy (analog, digital, etc.) by amplification and the current amplification principle of the transistor. The use of the triode is to play its role through two electrodes.

3.The scope of involvement is different:

The semiconductor triode is also known as the crystal triode, and it can be said that it is the most important device in the electronic circuit. Its main function is current amplification and switching. And the power tube is a classification in the classification of transistors, and the scope involved is very small, just as a branch of the triode.

The transistors in amplifier chips usually have high magnifications. However, the exact magnification depends on the design and application requirements of the amplifier chip.

For example, suppose there is a triode used in an amplifier chip with a magnification of 100. This means that when the input signal is amplified by the transistor, the amplitude of the output signal will be 100 times the amplitude of the input signal.

For example, if the amplitude of the input signal is volts, the amplitude of the output signal will be 10 volts (100 times the volts) after being amplified by the transistor.

This is just an example of the scale and does not represent the magnification of the transistors used in all amplifier chips. The magnification of the sail can be adjusted according to the design requirements, because there may be different magnification options in practical applications.

The transistor in the amplifier chip is not just a few times the magnification. In fact, the magnification depends on the characteristics and operating conditions of the transistor, including factors such as its circuit configuration, DC bias point, and amplitude of the AC input signal.

In general, the magnification of the transistor can range from tens to thousands, depending on the type and purpose of the transistor. For example, limb power amplifiers typically require higher amplifications, while signal amplifiers require lower amplifications. In addition, the magnification of the transistor will change with the change of temperature, frequency and other factors.

Therefore, it is not possible to simply solve the problem that the amplification of the transistor in the power amplifier chip is only a few times, and it needs to be analyzed on a case-by-case basis.

Triodes are often used as amplifiers in amplifier opening chips to amplify the input signal to higher levels. The magnification of each transistor depends on its design and manufacture, so different transistors may have different magnifications. In LON amplifier chips, multiple transistors are usually used to cascade to achieve a higher total magnification, so that the distribution can be used to achieve higher output power.

Therefore, the transistor amplification in the amplifier chip depends not only on the characteristics of the individual transistors, but also on the design and implementation of the entire circuit.

Triodes can have different magnifications depending on their specific model and design. In power amplifier chips, the transistor is usually used to amplify the electrical signal, increase the volume and power of the audio signal with the stool closed, and maintain the accuracy and quality of the audio signal while maintaining the accuracy and quality of the closed audio signal. Different transistor models and parameters can provide different magnifications and performance to meet different application needs.

Yes, but there are many components and it is troublesome. Buy a power amplifier circuit and simply assemble it to be successful. Such as TDA1521, TDA2030, etc., you can also buy fool series.

At present, there are not many successful ICs below 100W, and most of them are basically made of discrete parts in the above.

Of course, the power amplifier with large power has to be done with a large tube, and the noise of the final stage is very small, because the current and voltage are very large to cover up the weak noise signal. It is extremely difficult to make more than 100W power amplifier, 50W can do good achievements under amateur, and the performance is also unsatisfactory, which of course refers to discrete components, the optical guide wire due to the dry and self-excited formed by the large current will make you lose a lot, headache, the integrated circuit is relatively simple, the parameters, the effect is also guaranteed, recommended.

(1) An integrated circuit is a miniature electronic device or component. Using a certain process, the transistors, diodes, resistors, capacitors, inductors and other components and wiring required in a circuit are interconnected together, made on a small piece or several small pieces of semiconductor wafers or dielectric substrates, and then packaged in a tube shell to become a miniature structure with the required circuit function

2) The power integrated circuit has output power, the power integrated circuit is more discrete components, the temperature uniformity is good, the input impedance is played, the output impedance is small, and the occupied circuit area is small.

3) However, the power integrated chip is generally powered by dual power supplies, and the voltage is larger. Discrete components also have advantages, the noise can be lower (small signal), the power supply voltage is lower, cheap, and you can lap the circuit you want according to your experimental conditions, such as the 2011 electronic design competition D question can only use discrete components.

For general power amplifier circuits, the circuits of integrated circuit chips are relatively simple, the cost is lower than that of discrete components, the sound quality is acceptable (but it is difficult to achieve high-quality sound effects), and the power is also difficult to increase. Relatively speaking, the circuit design of the discrete component power amplifier is more complex, and the cost is relatively high, but the sound quality is better, and it is easier to increase the power.

The peripheral circuit with integrated chips is simple, the cost is low, and the sound quality is not much different from that of discrete components!

The role of the power tube is mainly to achieve high power output. The power tube must include a transistor or MOS transistor, and some power transistors (such as Darlington array ULN2001, ULN2002, ULN2003, ULN2004, ULN2803, etc.) also include diodes and resistors, as shown in the figure below

The power tube is also the power amplifier tube, which is at the last stage of the amplifier circuit, that is to say, the power tube contains one or more transistors, which are used for power amplification and may contain diodes.

Power tube refers to high-power tubes, of course, including electron tubes, diodes, transistors, thyristors, and FETs. The main condition is high power, and the power tube usually refers to the triode and the field effect transistor.

It is not necessarily in the amplified state when it is used, for example, the switching triode or FET of the switching power supply works in the switching state, and it is also a power tube. The line output tube for TV sets also operates in the switching state, while the output tube for power amplifiers operates in the amplified state. The above places are the places where power tubes are used more.

Summary. If the amplifier triode burns one pole electrode, it may be caused by the circuit of the pole is not working or there is a short circuit in the circuit. In this case, the current in the circuit is concentrated on the other two poles, causing the load capacity of these two poles to exceed their rated values, resulting in the amplifier triode burning out.

If you want to solve this problem, you first need to check whether there is a short circuit in the circuit, and if there is a short circuit, you need to eliminate it in time. Secondly, it is necessary to check whether the circuit of the pole is unobstructed, and if not, it is necessary to find out the cause and repair it. Finally, it is necessary to check whether the rated value of the power amplifier transistor meets the requirements of the circuit, and if it does not meet the requirements, a suitable triode needs to be replaced.

In short, there may be many reasons for the power amplifier transistor to burn one electrode, which needs to be troubled and repaired according to the specific situation. I hope mine can be helpful to you.

If the power amplifier triode burns one pole electrode, it may be caused by the circuit of the pole is not open or there is a short circuit in the circuit. In this case, the current in the circuit will be concentrated on the other two poles, causing the load capacity of these two poles to exceed their rated value, resulting in the amplifier triode burning out. If you want to solve this problem, you first need to check whether there is a short circuit in the circuit, and if there is a short circuit, you need to eliminate it in time.

Secondly, it is necessary to check whether the circuit of the pole is unobstructed, and if not, it is necessary to find out the cause and repair it. Finally, it is necessary to check whether the rated value of the power amplifier transistor meets the requirements of the circuit, and if it does not meet the requirements, a suitable triode needs to be replaced. In short, there may be many reasons for the power amplifier triode to burn one electrode, and it is necessary to carry out mold slippage and repair according to the specific situation.

I hope mine can be helpful to you.

Can you tell us more about that?

When the amplifier triode burns one pole, the current flow in the circuit will be affected, which may cause the banquet electrical appliances to not work properly or not work at all. If the emitter of the triode burns out, then the current in the circuit cannot flow and hence the appliance cannot work properly. If the base or collector of the transistor burns out, the current flow in the circuit will be restricted, resulting in improper electrical work.

If the transistor burns out, it needs to be replaced in time, otherwise it may cause damage to other electrical components. In addition, it is necessary to check whether the other components in the circuit are working properly to ensure that the appliance can work properly after replacing the triode. In short, when the power amplifier triode burns one pole, it will affect the current flow in the circuit, causing the electrical appliance to work abnormally or unable to work.

The transistor needs to be replaced in time, and other components need to be checked for normality.