Usually, in order to save time and convenience, we will unplug the amplifier power switch
when it is turned off, and also directly unplug when it is turned on. In fact, seemingly simple and convenient operation, there are great hidden dangers. (Next, please delineate the key points consciously) Because such operation will generate surge current and reverse peak voltage, it is easy to damage audio equipment and amplifier power switch, thereby reducing the life of the audio system and increasing the purchase cost.
What is surge current?
Sound equipment is composed of resistors, capacitors, inductors, transformers and other components. They are all in a cold state before starting. When the speaker power supply is turned on, the switching resistance of the amplifier power switch is small, so the instantaneous current is very large, which is 2.5-3.5 times the normal working current. This current is called surge current.
What is backpeak voltage?
Inductive elements, transformers and other units have a characteristic that when a voltage is added or removed in the circuit, the unit will produce a back EMF to prevent the voltage from changing. Then when a voltage is applied to the inductor, it produces a back EMF to prevent the voltage from being established, but the energy of the power supply voltage keeps on flowing, so the back EMF only acts as a voltage damper and has little effect on the circuit. However, the situation is different when the power is off. When the power is off, there is no obstruction in the circuit to produce a back EMF. This voltage is the back peak voltage. The reverse peak voltage is 9 times the normal voltage.