A compensated pulsed alternator, also known by the

portmanteau In linguistics, a blend—also known as a blend word, lexical blend, or portmanteau—is a word formed by combining the meanings, and parts of the sounds, of two or more words together.

''compulsator'', is a form of

power supply A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, electric current, current, and frequency to power ...

. As the name suggests, it is an

alternator An alternator (or synchronous generator) is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field wit ...

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

inertia Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newto ...

(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 In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term st ...

, 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 is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The electric current produces a magnetic field around the conductor. The magnetic field strength depends on the magnitude of the ...

. 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 (from Latin ''centrum'', "center" and ''petere'', "to seek") is the force that makes a body follow a curved trajectory, path. The direction of the centripetal force is always orthogonality, orthogonal to the motion of the bod ...

required to prevent the rotor from flying apart.

Usage

Compulsators are popular choices for high-end

railgun A railgun or rail gun, sometimes referred to as a rail cannon, is a linear motor device, typically designed as a ranged weapon, that uses Electromagnet, electromagnetic force to launch high-velocity Projectile, projectiles. The projectile norma ...

power supplies. One possibility being considered is to build an electric

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; ...

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 weapons (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.

References

{{reflist Bibliography * M. D. Werst, B. G. Brinkman, L. Spann.
Fabrication of a Compensated Pulsed Alternator For a Rapid Fire Railgun System
Center for Electromechanics,

University of Texas at Austin The University of Texas at Austin (UT Austin, UT, or Texas) is a public university, public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 stud ...

, Third Symposium on Electromagnetic Launch Technology, Austin, TX, April 20–24, 1986, IEEE Transactions on Magnetics, vol. 22, no. 6, November 1986, pp 1812–1816

External links

Jason Rollette's Compulsator page

FINAL DESIGN OF AN AIR CORE, COMPULSATOR DRIVEN 60 CALIBER RAILGUN SYSTEM ADVANCED COMPULSATOR DESIGN A RAPID FIRE, COMPULSATOR-DRIVEN RAILGUN SYSTEM
Power supplies Energy storage