Necessity of protection function
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Update time : 2024-07-29 17:55:50
Necessity of protection function
If you carefully browse the product details of Sinbosen's power amplifier, you can see functions such as "built-in overcurrent protection, high temperature protection, short circuit protection" without exception. How do these protection functions work specifically? Why can't they be missing?
Professional power amplifiers are very important components of audio systems. They are responsible for amplifying audio signals and outputting them to speakers. Since power amplifiers are usually the most powerful part of audio systems, protection functions are particularly important.
1. Soft start protection
In audio equipment with large current absorption, when the current value flowing through the power supply can reach 4-10 times its average current value at the moment of power supply, it is a shock to the power grid and the equipment itself, and in severe cases it will damage the equipment.
At this time, the soft start circuit can suppress the influx of current at the moment of device switching, allowing it to reach normal smoothly, playing a role in protecting the equipment and not causing power grid fluctuations. The negative temperature characteristics of thermistors (NTC) are usually used to achieve this function.
2. DC protection
When the output stage of the attack amplifier is damaged or the static bias is offset, a DC signal may be transmitted. As for the speaker, its working mode only generates impedance for AC signals, and it does not generate any impedance for DC signals (equal to zero impedance). At this time, the current is infinite, so the coil of the speaker is equivalent to a heating wire under DC signals and will be burned quickly.
Therefore, an accurate and fast DC protection circuit is very important. The DC protection start value of the power amplifier is usually set at 2V. When it is greater than or equal to this value, the power amplifier will cut off the output to protect the speaker. Of course, there are also power amplifiers that will cut off the output by burning the built-in DC fuse.
If the DC protection circuit of an amplifier is normal, but the coil of the speaker is burned, there are only two reasons: the power input to the speaker is too large, or the signal output by the amplifier is clipped and becomes a square wave.
3. Short circuit protection
When the output end of the power amplifier is short-circuited for some reason, the current output by the power amplifier will circulate in its own circuit and become infinite. This situation is very dangerous, so there must be an accurate and fast short-circuit protection circuit to protect the power amplifier equipment.
Normally, when a short circuit occurs, the amplifier will first control the input signal to reduce its amplitude or even to zero. If the situation does not improve, it will suppress the output current so that the current flowing inside the amplifier is always lower than the safe value of the output stage transistor.
4. Overcurrent protection
When the load of the amplifier is too low but has not reached the short circuit state, the short circuit protection will not work, but the output current will be very large and exceed the safe use value of the amplifier. At this time, the overcurrent protection circuit will intervene. The usual practice is to control the input voltage and output current so that the amplifier always works within a safe range.
5. Overheat protection
A well-designed amplifier will not have overheat protection under normal use. It will only work when the external use environment is harsh or an internal fault occurs. The hottest place of the entire amplifier is the C pole (collector) of the output stage transistor. Therefore, the temperature sensor for overheat protection is generally installed at the place closest to the C pole of the transistor or the hottest place on the radiator.
The threshold of overheat protection is generally 95℃, and there is also 105℃. The extreme temperature of the transistor is 105℃.
6. Distortion limiter
The input level value of audio equipment has a specified range. If it exceeds this range, the signal will be clipped, and in severe cases it will become a square wave. The function of the distortion limiter is to ensure that the level of the input signal is always controlled within the linear working range allowed by the audio equipment. The general standard is to start at THD1%.
The protection function can protect the power amplifier from short circuit, overload, overheating and other conditions that may cause damage. Once these conditions occur, the protection function automatically cuts off the power supply, thereby protecting the power amplifier and connected devices from damage.
The protection function can also extend the service life of the power amplifier and avoid the cost of frequent repairs and replacement of parts. By promptly detecting and preventing potential problems, the protection function can help users avoid unnecessary losses and troubles.
Therefore, the importance of the protection function of professional power amplifiers is self-evident. It can ensure the safety of equipment and users, extend the life of the equipment, and improve the stability and reliability of the audio system.
Sinbosen's power amplifiers have a comprehensive protection system and are also equipped with an upgraded cooling system, which is safe and powerful enough to support your performance for more than 20 hours!
If you carefully browse the product details of Sinbosen's power amplifier, you can see functions such as "built-in overcurrent protection, high temperature protection, short circuit protection" without exception. How do these protection functions work specifically? Why can't they be missing?
Professional power amplifiers are very important components of audio systems. They are responsible for amplifying audio signals and outputting them to speakers. Since power amplifiers are usually the most powerful part of audio systems, protection functions are particularly important.
1. Soft start protection
In audio equipment with large current absorption, when the current value flowing through the power supply can reach 4-10 times its average current value at the moment of power supply, it is a shock to the power grid and the equipment itself, and in severe cases it will damage the equipment.
At this time, the soft start circuit can suppress the influx of current at the moment of device switching, allowing it to reach normal smoothly, playing a role in protecting the equipment and not causing power grid fluctuations. The negative temperature characteristics of thermistors (NTC) are usually used to achieve this function.
2. DC protection
When the output stage of the attack amplifier is damaged or the static bias is offset, a DC signal may be transmitted. As for the speaker, its working mode only generates impedance for AC signals, and it does not generate any impedance for DC signals (equal to zero impedance). At this time, the current is infinite, so the coil of the speaker is equivalent to a heating wire under DC signals and will be burned quickly.
Therefore, an accurate and fast DC protection circuit is very important. The DC protection start value of the power amplifier is usually set at 2V. When it is greater than or equal to this value, the power amplifier will cut off the output to protect the speaker. Of course, there are also power amplifiers that will cut off the output by burning the built-in DC fuse.
If the DC protection circuit of an amplifier is normal, but the coil of the speaker is burned, there are only two reasons: the power input to the speaker is too large, or the signal output by the amplifier is clipped and becomes a square wave.
3. Short circuit protection
When the output end of the power amplifier is short-circuited for some reason, the current output by the power amplifier will circulate in its own circuit and become infinite. This situation is very dangerous, so there must be an accurate and fast short-circuit protection circuit to protect the power amplifier equipment.
Normally, when a short circuit occurs, the amplifier will first control the input signal to reduce its amplitude or even to zero. If the situation does not improve, it will suppress the output current so that the current flowing inside the amplifier is always lower than the safe value of the output stage transistor.
4. Overcurrent protection
When the load of the amplifier is too low but has not reached the short circuit state, the short circuit protection will not work, but the output current will be very large and exceed the safe use value of the amplifier. At this time, the overcurrent protection circuit will intervene. The usual practice is to control the input voltage and output current so that the amplifier always works within a safe range.
5. Overheat protection
A well-designed amplifier will not have overheat protection under normal use. It will only work when the external use environment is harsh or an internal fault occurs. The hottest place of the entire amplifier is the C pole (collector) of the output stage transistor. Therefore, the temperature sensor for overheat protection is generally installed at the place closest to the C pole of the transistor or the hottest place on the radiator.
The threshold of overheat protection is generally 95℃, and there is also 105℃. The extreme temperature of the transistor is 105℃.
6. Distortion limiter
The input level value of audio equipment has a specified range. If it exceeds this range, the signal will be clipped, and in severe cases it will become a square wave. The function of the distortion limiter is to ensure that the level of the input signal is always controlled within the linear working range allowed by the audio equipment. The general standard is to start at THD1%.
The protection function can protect the power amplifier from short circuit, overload, overheating and other conditions that may cause damage. Once these conditions occur, the protection function automatically cuts off the power supply, thereby protecting the power amplifier and connected devices from damage.
The protection function can also extend the service life of the power amplifier and avoid the cost of frequent repairs and replacement of parts. By promptly detecting and preventing potential problems, the protection function can help users avoid unnecessary losses and troubles.
Therefore, the importance of the protection function of professional power amplifiers is self-evident. It can ensure the safety of equipment and users, extend the life of the equipment, and improve the stability and reliability of the audio system.
Sinbosen's power amplifiers have a comprehensive protection system and are also equipped with an upgraded cooling system, which is safe and powerful enough to support your performance for more than 20 hours!
