First, the difference in the form of output:
Constant pressure and fixed resistance are different in output form:
1. The constant pressure is not a certain voltage, but the output form is constant pressure, which requires the rated voltage of the load to be constant. The constant voltage amplifier is connected in parallel with a plurality of constant voltage speakers as long as the total power does not exceed the total power of the constant voltage amplifier.
2. The fixed resistance power amplifier requires a certain output load resistance. In a fixed-resistance amplifier, if the load impedance changes, the power changes. The 8 ohm 100W fixed-resistance amplifier becomes 4 ohms and becomes close to 200W.
Second, the characteristics of constant pressure amplifier:
In a constant voltage amplifier, if the rated load voltage changes, the power changes accordingly. The 100V, 10W speaker is connected to the 5V at 5V (the power difference between 100V and 70V is doubled).
The domestic constant pressure standard is 120V, 240V. The foreign constant pressure standard is 70V, 100V.
Third, the characteristics of fixed resistance amplifier:
Power amplifiers with fixed resistance outputs: These amplifiers require a constant impedance of the load. When the input signal is constant, the output voltage varies greatly with load.
Power amplifier with constant voltage output: Since the deep negative feedback device is used in the amplifier, the deep negative feedback is generally above 10~20dB. Therefore, the output impedance of the amplifier is low and the load changes within a certain range. The output voltage can still maintain a certain value, and the sound quality can remain unchanged.
Fourth, the difference between constant pressure power amplifier and fixed resistance power amplifier application:
Constant pressure is used to require a large space where the sound quality is not very high. On the contrary, the fixed resistance can only be transmitted within 100 meters due to the limitation of transmission. Therefore, it is generally used in a small space when the sound effect is relatively good. The general broadcast system uses a constant voltage output, and the sound system uses a fixed resistance output.
Commonality: Both audio signals from computers, CDs, DVDs, etc. can be amplified together to drive the speakers.Their respective characteristics:
One: constant pressure amplifier
1 used in public places
2 mono output
3 high voltage and low current output
Constant voltage amplifiers are mainly used for public broadcasting in public places, and also for background music of the family. Because the distance between the public broadcasting and background music system speakers and amplifiers is relatively long, and one power amplifier usually has to connect multiple low-power speakers. In order to reduce the line loss, avoid the influence of the opening or closing of a certain speaker in the system on the volume of other speakers, so the constant voltage amplifier has a high voltage and low current output [relative]. Pressurize the power amplifier to connect multiple speakers, just connect the speakers in parallel on a common wire.
Because the constant voltage work is placed on the circuit using a transformer, its sound quality is affected to some extent. However, if you choose a high-quality broadcast speaker, you can completely improve the sound quality of the broadcast system.
Two: fixed resistance amplifier
1 for home theater, KTV, stage
2 stereo output
3 low voltage and high current output Because the distance between the home theater, stage and other speakers and the power amplifier is relatively close and there is no need to connect a lot of speakers, so the high power and low voltage output of the power amplifier is set, and the dedicated audio cable is connected to the power amplifier and the sound response.
The following describes the characteristics of the broadcast speaker:
Most broadcast speakers now have an inter-line transformer inside, so there is no need to install a separate transformer when using it.
Constant voltage speakers for broadcasting can be connected in parallel when in use.
Broadcast speaker power is generally small
Supermarket ceiling speaker power is 3W-10W
The wall-mounted speaker power of the classroom is 3W-10W
Outdoor broadcast sound column power is 10W-100W
The power of the tweeter is 5W-25W
Fixed resistance speaker power is generally large
Home theater's main speaker power is 80W-300W
KTV's speaker power is 80W-300W
Stage speaker power is 200W-1000W
It is best not to connect multiple speakers in parallel with a fixed-resistance speaker.
So how do you distinguish between fixed-resistance and constant-voltage speakers? How to distinguish between fixed-resistance amplifier and constant-voltage amplifier?
Look at the back of the speaker to indicate the voltage is the constant pressure speaker, the set resistor is the set of speakers. In general, fixed-tone speakers are more common.
Differentiate the fixed-resistance power amplifier and the constant-voltage power amplifier to see the power amplifier. The output end is marked with a fixed-resistance power amplifier. The output voltage is a constant-voltage power amplifier. Now most of the constant-voltage power amplifiers have a fixed-resistance output function, so the output is behind. There are also marked resistors on the terminals.
Pin Header Connector,Pin Header Female,Male Header Pins,Right Angle Pin Header
Cixi Xinke Electronic Technology Co., Ltd. , https://www.cxxinke.com