dc machines
... sources associated with the field windings and the reluctances of the various machine components in the direction of the magnetic flux [poles, air gaps, rotor teeth, rotor core and the outer portion of the stator (yoke)] (see Figure 4.21, p. 142). At low values of magnetic flux density, the reluctan ...
... sources associated with the field windings and the reluctances of the various machine components in the direction of the magnetic flux [poles, air gaps, rotor teeth, rotor core and the outer portion of the stator (yoke)] (see Figure 4.21, p. 142). At low values of magnetic flux density, the reluctan ...
Measurement of transient force produced by a propagating arc
... Magnetohydrodynamic (MHD) plasma actuators have been proposed for control of high-speed flows, albeit at low pressures (Mach number 5–10, static pressure 1.4–5.5 kPa) [8]. More recently, our group proposed an MHD rail plasma actuator (RailPAc) suitable for atmospheric pressure flow actuation applica ...
... Magnetohydrodynamic (MHD) plasma actuators have been proposed for control of high-speed flows, albeit at low pressures (Mach number 5–10, static pressure 1.4–5.5 kPa) [8]. More recently, our group proposed an MHD rail plasma actuator (RailPAc) suitable for atmospheric pressure flow actuation applica ...
Commutator
... Brush friction loss Pbf = μ pb AB.Vc μ – Coefficient of friction pb-Brush contact pressure on commutator (N/m 2) AB - Total contact area of all brushes (m2) AB =P Ab (for lap winding) = 2 Ab (for wave winding) Vc – Peripheral speed of commutator (m/s) ...
... Brush friction loss Pbf = μ pb AB.Vc μ – Coefficient of friction pb-Brush contact pressure on commutator (N/m 2) AB - Total contact area of all brushes (m2) AB =P Ab (for lap winding) = 2 Ab (for wave winding) Vc – Peripheral speed of commutator (m/s) ...
1em-dcmachinesstructureworkingtypes
... It is cylindrical in shape with slots to carry armature winding. The armature is built up of thin laminated circular steel disks for reducing eddy current losses. It may be provided with air ducts for the axial air flow for cooling purposes. Armature is keyed to the shaft. • Armature winding ...
... It is cylindrical in shape with slots to carry armature winding. The armature is built up of thin laminated circular steel disks for reducing eddy current losses. It may be provided with air ducts for the axial air flow for cooling purposes. Armature is keyed to the shaft. • Armature winding ...
DC Motor Theory
... When the opposite poles are at their strongest attraction, the armature will be "locked up" and will resist further attempts to continue spinning. For the armature to continue its rotation, the armature's polarity must be switched. Since the armature in this diagram is a permanent magnet, you can se ...
... When the opposite poles are at their strongest attraction, the armature will be "locked up" and will resist further attempts to continue spinning. For the armature to continue its rotation, the armature's polarity must be switched. Since the armature in this diagram is a permanent magnet, you can se ...
Review of Inductive Pulsed Power Generators for Railguns
... than 2 stages. In high-energy pulsed-power systems, this multiplier technique simplifies the primary power design at the expense of more complex switching. The term XRAM generator originates from the well-known Marx generator where capacitors are charged in series and discharged in parallel to gener ...
... than 2 stages. In high-energy pulsed-power systems, this multiplier technique simplifies the primary power design at the expense of more complex switching. The term XRAM generator originates from the well-known Marx generator where capacitors are charged in series and discharged in parallel to gener ...
L-11 Back emf - Synergy Dhenkanal
... armature conductors move through the magnetic field and hence e.m.f. is induced in them as in a generator The induced e.m.f. acts in opposite direction to the applied voltage V(Lenz’s law) and in known as back or counter e.m.f. Eb. The back e.m.f. Eb (= P Φ ZN/60 A) is always less than the applied v ...
... armature conductors move through the magnetic field and hence e.m.f. is induced in them as in a generator The induced e.m.f. acts in opposite direction to the applied voltage V(Lenz’s law) and in known as back or counter e.m.f. Eb. The back e.m.f. Eb (= P Φ ZN/60 A) is always less than the applied v ...
phase advancers
... (i) The phase of the induced e.m.f is reversed. (ii) Now the armature of the exciter acts as a capacitor instead of a choke. Overall p.f. of the SRIM improves. ...
... (i) The phase of the induced e.m.f is reversed. (ii) Now the armature of the exciter acts as a capacitor instead of a choke. Overall p.f. of the SRIM improves. ...
Neutral zone - Schunk Carbon Technology
... It is thus necessary to insure that voltage is not induced in the commutator loop at the time of the momentary short. If the short occurs when the active conductors in the armature loop are moving in parallel to the field, magnetic lines of force will not be cut and voltage will not be induced in th ...
... It is thus necessary to insure that voltage is not induced in the commutator loop at the time of the momentary short. If the short occurs when the active conductors in the armature loop are moving in parallel to the field, magnetic lines of force will not be cut and voltage will not be induced in th ...
practical File
... armature voltage is kept constant. By decreasing the flux the speed can be increased and vice – versa. Hence the main flux of field control method the flux of a DC motor can be changed by changing field current with help of a shunt field rheostat. Since shunt field current is respectively small shun ...
... armature voltage is kept constant. By decreasing the flux the speed can be increased and vice – versa. Hence the main flux of field control method the flux of a DC motor can be changed by changing field current with help of a shunt field rheostat. Since shunt field current is respectively small shun ...
Railguns
... The last major area of railgun engineering is design of the firing mechanism. When using a compulsator to power the gun, timing of the firing is crucial. The goal for the firing mechanism is to tap the power signal at the desired voltage. The simplest way to perform this is by using a shaft encoder ...
... The last major area of railgun engineering is design of the firing mechanism. When using a compulsator to power the gun, timing of the firing is crucial. The goal for the firing mechanism is to tap the power signal at the desired voltage. The simplest way to perform this is by using a shaft encoder ...
Railgun
A railgun is an electrically powered electromagnetic projectile launcher based on similar principles to the homopolar motor. A railgun comprises a pair of parallel conducting rails, along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail.Railguns are being researched as a weapon with a projectile that would use neither explosives nor propellant, but rather rely on electromagnetic forces to achieve a very high kinetic energy. While current kinetic energy penetrators such as an armour-piercing fin-stabilized discarding-sabot can achieve a muzzle velocity on the order of Mach 5, railguns can potentially exceed Mach 10, and thus far exceed conventionally delivered munitions in range and destructive force, with the absence of explosives to store and handle as an additional advantage.In addition to military applications, NASA has proposed to use a railgun from a high-altitude aircraft to fire a small payload into orbit; however, the extreme g-forces involved would necessarily restrict the usage to only the sturdiest of payloads.