What is synchro?Is it relalated in any way to stepper motor?
Synchros are electromagnetic devices which are used to transmit angular displacement ,velocity e.t.c.It is commercially known as selsyn or autosyn.The types of synchros according to operations are given below:
1.synchro transmitter: This is an electromechanical unit in which the input ,the mechanical signal is given to the rotor is converted into an electrical signal in the stator.
2.Synchro receiver.:This is also known as synchro control transformer,in which the input electrical signal given to the stator is converted to the mechanical signal[angular displacement] in the rotor.
3.Synchro differential transmitter and differential receiver:The differential transmitter is an electro mechanical unit in which the rotor is driven mechanically to modify the received signal and to transmit an electrical signal which is the sum of difference of impressed signal and modified signal.
Synchros are electromagnetic devices which are used to transmit angular displacement ,velocity e.t.c.It is commercially known as selsyn or autosyn.The types of synchros according to operations are given below:
1.synchro transmitter: This is an electromechanical unit in which the input ,the mechanical signal is given to the rotor is converted into an electrical signal in the stator.
2.Synchro receiver.:This is also known as synchro control transformer,in which the input electrical signal given to the stator is converted to the mechanical signal[angular displacement] in the rotor.
3.Synchro differential transmitter and differential receiver:The differential transmitter is an electro mechanical unit in which the rotor is driven mechanically to modify the received signal and to transmit an electrical signal which is the sum of difference of impressed signal and modified signal.
There are two distinctly different ways of using stepper motors in control systems.One is the open loop mode and other is the closed loop mode.
The stepper motor is a digital device whose output in shaft angular displacement is completely determined by the number of input pulses.Consequently,there is no need for a feedback device to determine the position of motor shaft and ,therefore,of the load connected to the motor shaft.This means that an open –loop step servo system can be designed to yield the the same accuracy as that of a closed loop analog system.figure(1) shows use of stepper motor in open loop mode. Use of steppermotor in closedloop mode requires synchros as error detector.Here the motor is used like conventional servomotor.A signal from the output is fed back and is used to operate a gate controlling the pulses from a pulse generator.This is shown in the figure below:
The stepper motor is a digital device whose output in shaft angular displacement is completely determined by the number of input pulses.Consequently,there is no need for a feedback device to determine the position of motor shaft and ,therefore,of the load connected to the motor shaft.This means that an open –loop step servo system can be designed to yield the the same accuracy as that of a closed loop analog system.figure(1) shows use of stepper motor in open loop mode. Use of steppermotor in closedloop mode requires synchros as error detector.Here the motor is used like conventional servomotor.A signal from the output is fed back and is used to operate a gate controlling the pulses from a pulse generator.This is shown in the figure below:
Reference:
(1)Control Systems Engineering-I.J Nagarath,M.Gopal
(2)Control Systems Engineering-S.N Sivanandam
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