How to understand the relationship between output impedance and load-carrying capacity

Output impedanceIs the internal resistance of a signal source.

For an ideal voltage source (including power supply), the internal resistance should be 0, or the impedance of the ideal current source should be infinite.

In reality, voltage sources cannot do this. We often use an ideal voltage source to concatenate a resistor R to equivalent an actual voltage source. The resistance R in connection with the ideal voltage source is the internal resistance of the signal source/amplifier output/power supply. When the voltage source powers the load, there will be a current I flowing from this load, and the voltage drop of I × R will be generated on this resistance. This will cause the power supply output voltage to drop, thus limiting the maximum output power.

Similarly, for an ideal current source, the output impedance should be infinite, but the actual circuit is impossible. In fact, the current source is equivalent to an ideal current source. The resistance is the output impedance R. The larger the value of R, the closer it is to the open circuit. The smaller the impact on the subsequent circuit, because the resistance of the circuit following is connected in parallel, this infinity is still itself.

The load-carrying capacity can be understood as the output power. For example, the more powerful the load-carrying capacity is that it can drive a bicycle, and now it can drive a car forward. Load can be bulbs, speakers, motors, etc.

According to the principle of resistance partial pressure, the partial pressure in the series circuit is proportional to the resistance value. The larger the resistance value, the higher the voltage, the smaller the output resistance of the voltage amplification circuit, in the same power consumption conditions, the lower the voltage consumed by the load with the same impedance, the higher the load voltage, therefore, an amplifier with a low output resistance can carry a load with a higher power and a lower internal resistance compared to an amplifier with a high output resistance.
The relationship between "larger power" and "smaller internal resistance" means that under the same conditions, if the pipe power is different, there will be no comparability.
The load power is related to the power supply voltage and the output current of the last-level drive tube, but if the selected tube has a small internal resistance, this allows as many electric energy as possible to be sent to the load rather than consumed on the power tube. In this way, we can refer to "larger power" when there are as many electric energy inputs, in fact, it is more efficient.
Generally, a high-power amplifier uses a MOSFET tube because its internal resistance is smaller.
 

In general, the smaller the voltage source output impedance, the better, and the larger the current source output impedance, the better (Note: Only suitable for low frequency circuits, in high frequency circuits, also consider the impedance matching problem. In addition, except for signal sources that require throttling or pressure limiting protection ).