Compulsator
Encyclopedia
A compensated pulsed alternator, also known by the portmanteau compulsator, is a form of power supply
.
As the name suggests, it is an alternator
that is "compensated" (see below) to make it better at delivering pulses of electrical energy than a normal alternator.
(having been "spun up" by an external motor, or the compulsator itself having been used in reverse as an AC motor) and the small matter of the "compensation". The compulsator is used like a capacitor
, to gather energy from a low-power source and store it, then generate a high-power output for a short period.
The windings of a compulsator are different from those of a normal alternator in being designed for minimal inductance
. This allows the current in the windings to change very rapidly, which is why this "compensation" makes it better at delivering pulses.
The kinetic energy of a rotating object depends on the mass of the object, the shape of the object, and the square of the speed of rotation. Therefore, compulsators tend to have very light rotors spinning very fast in order to store the most energy in the available mass, and because too much mass in the rotor causes problems with the magnitude of centripetal force
required to prevent the rotor from flying apart.
power supplies. One possibility being considered is to build an electric tank
using a conventional diesel engine for propulsion and to charge a compulsator. The compulsator would be used to power a railgun, and potentially other pulsed energy weapon
s (particularly electronic warfare
systems); also, the compulsator could be used in non-pulsed mode to drive a tank with electric motors for limited periods as a kind of "quiet mode", which could be useful in urban combat.
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
.
As the name suggests, it is an alternator
Alternator
An alternator is an electromechanical device that converts mechanical energy to electrical energy in the form of alternating current.Most alternators use a rotating magnetic field but linear alternators are occasionally used...
that is "compensated" (see below) to make it better at delivering pulses of electrical energy than a normal alternator.
Description and operation
The principle is very similar to an alternator, except the rotor is usually kept spinning by its inertiaInertia
Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to...
(having been "spun up" by an external motor, or the compulsator itself having been used in reverse as an AC motor) and the small matter of the "compensation". The compulsator is used like a capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
, to gather energy from a low-power source and store it, then generate a high-power output for a short period.
The windings of a compulsator are different from those of a normal alternator in being designed for minimal inductance
Inductance
In electromagnetism and electronics, inductance is the ability of an inductor to store energy in a magnetic field. Inductors generate an opposing voltage proportional to the rate of change in current in a circuit...
. This allows the current in the windings to change very rapidly, which is why this "compensation" makes it better at delivering pulses.
The kinetic energy of a rotating object depends on the mass of the object, the shape of the object, and the square of the speed of rotation. Therefore, compulsators tend to have very light rotors spinning very fast in order to store the most energy in the available mass, and because too much mass in the rotor causes problems with the magnitude of centripetal force
Centripetal force
Centripetal force is a force that makes a body follow a curved path: it is always directed orthogonal to the velocity of the body, toward the instantaneous center of curvature of the path. The mathematical description was derived in 1659 by Dutch physicist Christiaan Huygens...
required to prevent the rotor from flying apart.
Usage
Compulsators are popular choices for high-end railgunRailgun
A railgun is an entirely electrical gun that accelerates a conductive projectile along a pair of metal rails using the same principles as the homopolar motor. Railguns use two sliding or rolling contacts that permit a large electric current to pass through the projectile. This current interacts...
power supplies. One possibility being considered is to build an electric tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
using a conventional diesel engine for propulsion and to charge a compulsator. The compulsator would be used to power a railgun, and potentially other pulsed energy weapon
Pulsed energy weapon
A pulsed energy weapon is any weapon that:* uses pulses of electricity to fire a projectile, or* operates by transferring electric current to its target....
s (particularly electronic warfare
Electronic warfare
Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...
systems); also, the compulsator could be used in non-pulsed mode to drive a tank with electric motors for limited periods as a kind of "quiet mode", which could be useful in urban combat.