1, rated power
Calculation: rated current * rated voltage or rated voltage squared / thermal resistance
Rated power is the power generated by a specific resistance value when the device is at a rated voltage (such as AC?220V).
2, the actual power
Calculation: actual current * actual voltage or actual voltage squared / current thermal resistance
The actual power can be understood as the power generated in the actual voltage, such as the actual input voltage fluctuations 215-230V are possible, so the actual power will change.
3, the actual power and rated power relationship:
①U real = U amount, then P real = P amount, the normal operation of the appliance;
②U real & lt; U amount, then P real & lt; P amount, the appliance can not work properly;
3 U real & gt; U amount, then P real & gt; P amount, the damage may be caused to the appliance.
Extended information
Difference:
The electrical power of an appliance changes with the change in voltage applied to its terminals. Also, an appliance doesn't work on just any circuit it is plugged into. When designing an appliance, you need to determine the voltage at which it normally operates, i.e., the rated voltage, and the power at which it operates, i.e., the rated power. An electrical appliance is produced, its rated voltage, rated power is determined.
The actual voltage, the actual power is uncertain, to change with the working conditions of the appliance and change. Only when the actual voltage on both sides of the appliance is equal to the rated voltage, the actual power is equal to the rated power, the appliance can work properly, the light bulb can be normal light. The brightness of the lamp is determined by the size of the actual power,
The actual voltage and the actual power of the appliance is changing with the circuit changes, the rated voltage and the rated power is unchanged, when they are given as a known condition, according to the formula can be found out the size of the resistance of the appliance resistance.
No matter what circuit the appliance is connected to, although the circuit characteristics are different, their resistance value is certain. In the series circuit the real power is proportional to the resistance, in the parallel circuit, the real power is inversely proportional to the resistance, so as to get the relationship between the size of the real power.
Baidu Encyclopedia - Power Rating
Baidu Encyclopedia - Actual Power