The power meter measures the current and voltage of the circuit and displays the product of them on the dial. If the current and voltage are in the same direction, it means that the load consumes electric energy, and the power meter indicates a positive value (positive bias). The reverse bias shows that the current and voltage directions are inconsistent, and the load does not consume electric energy, but transmits electric energy to the circuit.
Extended data:
Power refers to the number of tasks representing the speed of an object. Power P = J/ time t is in physical work, and the unit is ww. We often see media kilowatt power equipment, such as Ps, HP, BHP Billiton WHPMW, etc. , are international standard units with previous resumes and Italian kilowatts, 1 kw = 1 000 w, 1 sec later.
In daily life, power is often called horsepower and horsepower unit, just as torque is called torque.
In the automobile world, the machine that does the most work is the engine, and the power of the engine is calculated by torque. The formula is simple: power (w) = 2× torque (Nm)× RPM)/60, which is simplified as power (w) = torque (Nm)× RPM)/9.549.
Because of the difference between English and metric systems, the definition of horsepower is completely different. Horsepower (HP) is defined in the British system as a horse pulling 200 pounds (lb) in one minute and weighing 165 feet (ft). Multiply it by 33,000 pound feet per minute.
In metric units, horsepower (PS) is defined as a horse pulling 75 kilograms of material 60 meters in one minute, that is, 4500 kilograms g.m/min.