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Cored Motors: The heavy rotating mass [core] of these electric motors known as an armature is comprised of metal plates [poles] sandwiched around a metal shaft, the metal shaft is supported at both ends by bearings, and each pole is wrapped with copper wire [windings]. More poles, equals more windings which in turn creates smoother operation. The armature spins at high rpm in a permanent hollow center magnet The armature spins within the inside diameter of the magnet. Power is introduced to the windings, which in turn creates an electro-magnetic field. This field is opposed by the magnet which in turn causes the armature to rotate. Coreless Motors: Coreless motors operate within the same design concepts, but are assembled in a different manner. The windings are formed into a cylindrical shape. The armature is fixed to a metal shaft at one end and rotates around the outside diameter of a permanent hollow center magnet. Coreless motors respond faster, smoother and more precisely with more force due to their light-weight. The lack of poles opposed by electro-motive force [EMF] allows the coreless armature to center more accurately while maintaining or holding position with increased authority [there is no space between poles, thus more positions to rest at]. Analog and digital servos share the same internal components less the servo amplifier [the device which commands the servos position]. Analog Amplifiers: Analog amplifiers interpret RX command and pulse power [on/off] to the armature at about 50 cycles per second. No power is consumed at idle. Power is delivered at full available voltage. The potentiometer feeds position info to the amplifier. If a signal is received from the RX or the servo arm is deflected the amplifier pulses power to either move too or resist the opposing force. The amplifier compares position to commands and reacts by alternating the duration of the pulse to speed up or slow down the servo motor causing it to move to or hold the commanded position. Digital Amplifiers: Digital amplifiers interpret RX signals and operate within fixed parameters. Center, end points and maximum speed are preset parameters. The preset commands together with commanded position are then delivered to the servo motor. The duration of the power pulse and the amount of power utilized to activate the servo motor varies dependent on the need. Digital amp's send power pulses to the servo motor at 300 cycles per second. [power is consumed at idle]. Known result [servo buzzing]... The increased pulse cycles command the servo motor to react and perform with more precision because of the increased pulse frequency or interval. Net results are faster response to control command signals, lower dead-band numbers, increased holding power and much better resolution. Programmable Digital amplifiers have a programmable memory which can be altered via a programmer. The servo operation parameters therefore can be manipulated within to the user's individual needs. Center and end-point positions, speed, dead-band, rotation, failsafe and more are programmable. |
          
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