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.
Description and operation
The principle is very similar to an alternator, except the rotor is usually kept spinning by its
inertia (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
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The 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
A centripetal force (from Latin ''centrum'', "center" and ''petere'', "to seek") is a force that makes a body follow a curved path. Its direction is always orthogonal to the motion of the body and towards the fixed point of the instantaneous c ...
required to prevent the rotor from flying apart.
Usage
Compulsators are popular choices for high-end
railgun 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
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.
These weapons often use large capacitors to build up a charge which is released when the we ...
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.
References
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, 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
*{{deadlink, date=August 2021
A RAPID FIRE, COMPULSATOR-DRIVEN RAILGUN SYSTEM
Power supplies
Energy storage