Aircraft rely on fuel for propulsion, but electricity is just as vital for flight as well. Everything from instruments to lights to setback TVs in commercial passenger jets rely on electricity, which is generated as some of the energy produced by fuel being burned goes into a generator or alternator that produces electricity.
Pilots also need a way to monitor these systems and determine if there are issues that need resolving. A pilot can fly on stored battery power, but losing the generator or alternator is a serious concern. Therefore, electrical systems are measured by a special tool called an ammeter, a device that measures electric current flow moving through a wire or circuit. Early ammeters were lab instruments that relied on the Earth’s magnetic field for operation, but by the 19th century had improved to the point that they could be mounted in any position and allowed for accurate measurements in electric power systems.
The main purpose of the ammeter is to monitor an electrical system’s performance. Ammeters show if the alternator or generator is producing enough electricity, and if the battery is receiving that electricity. An ammeter consists of a pointing needle on a horizontal scale with a value of zero at the center, positive numbers to the right, and negative numbers to the left. A negative number means that more electricity is being used than is being generated, and a positive number means more electricity is being given to the battery than is being used. Most of the time, the needle should be in the middle or slightly to the right. If the ammeter goes to the far right, that means that the regulator is malfunctioning, and if it goes to the far left it means that the generator or alternator is malfunctioning. Some aircraft use warning lights instead of ammeters, but the purpose is effectively the same.
The generator or alternator malfunctioning is the most important piece of information the pilot needs if an electrical problem arises, and helps the pilot determine if it can be resolved in the air, or if the car needs to be landed immediately.
Warrantied inventory at competitive prices
Search the world's largest inventory of electronic components by manufacturer, category or part number
All inventory ready to ship from our sellers
We sell only warrantied and traceable parts
If You Need Parts to Be Shipped Out Quickly and Affordably, Please Remember Us Next Time For Your Requirements of NSN Parts!Request for Quote