Examen EASA M4

A resolver synchro output is obtained from a rotor with. one single coil. two coils at 90° to each other. three coils at 120° to each other.

The output of a resolver synchro is. dependant upon the position of the rotor only. proportional to the speed of input rotation. a function of the rotor position and excitation voltage.

The rotor of an autosyn position indicating system is. a permanent magnet. spring controlled. an electromagnet.

The rotor of a magnesyn transmitter is. a permanent magnet. an ac electromagnet. a dc electromagnet.

Torque synchro systems are normally used when the. system accuracy is of extreme importance. mechanical load is high. mechanical load is low.

In a resolver synchro the stator windings are electrically disposed by. 90°. 120°. 180°.

What device transfers one energy type to another?. Transponder. Transducer. Transmitter.

Electrical power is supplied to a synchro rotor. through slip rings. through a commutator. directly.

In a synchro resolver, the stator coils are at what angle in relation to one another?. 45 degrees. 80 degrees. 90 degrees.

An increase in negative feedback to the servo amplifier. has no effect. increases amplifier stability. decreases amplifier stability.

In a synchro, what is used to convert signals from one form to another?. Transducer. Transmitter. Transformer.

A control surface position feedback signal is. inversely proportional to surface position. proportional to surface position. non-linear.

A position gyro will provide. acceleration feedback. velocity feedback. positional feedback.

In velocity feedback the signal is. out of phase. in phase. equal to the error signal.

If velocity feedback in a servo system is above optimum, this will cause. no effect. sluggish operation. hunting.

The amount of rate feedback from a tachogenerator is. proportional to speed. constant for all servo speeds. inversely proportional to speed.

What control system is used on an input that gives a controlled predetermined output?. Control Servo. Closed Loop. Open Loop.

Increasing velocity feedback from optimum will give. faster performance. sluggish performance. no change on the output.

A rate control servo system with a steady input voltage will give. decreasing speed. increasing speed. constant speed.

An increase in amplitude of a rate feedback signal will cause. sluggish servo operation. unstable operation. reduced hunting.

An increase in negative feedback. decreases system sensitivity. increases system sensitivity. will make the driven device continuously rotate.

Position feedback is used to. indicate to the pilot the position of the load. to prevent control surface oscillations while the surface is being moved. ensure control surface moves to the demanded position by the controls.

The output from a control transformer is. torque. AC voltage. DC voltage.

The stator output voltages from a synchro resolver are. 3 phase. AC single phase. DC.

A typical use for resolver synchros is. fly by wire system. engine power instrumentation. in compass comparator units.

What does a resolver do?. Adds two signals. Resolves a movement into sine and cosine components. Resolves a position into sine and cosine components.

If the feedback is ideally damped, the signal will. overshoots once and return back. not overshoot. oscillate.

In a tachogenerator the output voltage is. inversely proportional to the speed. zero. directly proportional to the speed.

The primary purpose of rate feedback in a positional servo system is to. ensure system linearity. prevent excessive overshoot. ensure minimum response time.

In a control surface position indicating system the feedback signal is. in phase with the control surface position. indirectly proportional to the control surface position. proportional to the control surface position.

Synchro systems depend on the principles of. electromagnetic induction. capacitive reaction. mutual Inductance.

A piezoelectric crystal is an example of. an analogue transducer. a Pneumatic Transducer. a Electro Acoustic Transducer.

The difference between an open and closed loop is. error signal. feedback. correspondence.

In a Desynn indicator system, where is power supplied to?. Transmitter and indicator. Indicator only. Transmitter only.

What does the Desynn indicator rotor consist of?. Electro magnet. Permanent Magnet. Aluminium cored coil.

When a servomotor overshoots after a step input and oscillates it is. under damped. over damped. critically damped.

A reduction from the optimum setting of the velocity feedback in a servo loop could cause. instability. slow response. ow servo gain.

The phase difference between the supplies of a two phase induction motor is. 90°. 180°. 0°.

If the rotor of the receiver in a torque synchro system was prevented from aligning with the transmitter rotor, then. the transmitter rotor will turn to align with the receiver rotor. the receiver will hunt. the receiver will overheat.

An E&I bar output at datum has. an imbalance of voltages in the secondary windings. no induced voltage in the secondary windings. equal and opposite voltages induced in the secondary.

The result of cross connecting two of the transmission leads in a torque synchro system and then turning the rotor of the transmitter 60° clockwise would be. the receiver would move 60° clockwise. the receiver would move 60° anticlockwise. the receiver would move 120° anticlockwise.

The control windings of a two phase servomotor is supplied with AC voltage of. variable amplitude, variable phase. variable phase. constant amplitude.

If the rotor of a control synchro sticks. the system hunts. the position feedback will oscillate. high current will flow.

With the reversal of the connections to the rotor of the transmitter of a torque synchro, the position of the receiver rotor will be. changed by 120°. unchanged. changed by 180°.

The application of a "stick-off" voltage to a control synchro servo system is. to overcome the effect of static friction. to overcome the effect of viscous friction. to prevent alignment to a false null.

A servo system may include a brake, an automatic trim system is one example where a brake is used. The brake is. applied when trimming is complete to prevent stabilizer creep. applied during trimming to prevent oscillations about the demand position. applied during trimming to prevent servo runaway.

In a control synchro the stator current ceases to flow when. the CT rotor is at null. when power is removed. when the two rotors are aligned.

The result of reversing the rotor connections to the receiver of a torque synchro system is that the rotor position. is changed by 180°. is unchanged. is changed by 120°.

A two phase induction motor used in a servomechanism. will always require a starter. runs with no slip. is self starting under light loads.

A hysteresis servo motor is used in a servomechanism because. it has good starting characteristics. good speed/voltage relationship. low inertia.

Reversal of two of the stator connections on a torque synchro receiver would cause. the transmitter to become the receiver. the output to move the same direction as the input. the output to move the reverse direction to the input.

The output of a tachogenerator should be. exponential. linear. sinusoidal.

With a constant input to a speed control servo, the servo motor. moves to a certain position. moves at a constant speed. oscillates, but otherwise does not move.

Critical damping in a servomechanism is. the point which allows just one overshoot before the load comes to rest. the amount of damping that results in the load just not oscillating. the critical damping required for the optimum damping of the servomechanism.

Reverse rotation of a control transformer rotor can be caused by. connections to the transmitter rotor reversed. connections between the transformer rotor and the amplifier reversed. short circuit between two transmission lines.

Velocity lag can be decreased by. keeping the error detector (summing point) output as low as possible. introduction of an integrator. decreasing the coulomb friction in the system.

A two phase motor will stop when. the control phase is reversed. the reference phase is reversed. the control phase is zero.

A tachogenerator output is. variable frequency, constant voltage. variable frequency, variable voltage. variable voltage, constant frequency.

If two of the stator leads are cross connected in a control synchro system, a 25° clockwise rotation of the input rotor would result in the output rotor. moving 180° to rectify the defect. moving 25° anticlockwise. moving 25° clockwise.

Damping in a servomechanism is easier to apply if. the mechanism is light and has high inertia. the mechanism is light and has low inertia. the mechanism is heavy and has high inertia.

If the electrical connections to the feedback generator in a control synchro system were disconnected, the. motor would run in the wrong direction. input signal to the amplifier would reduce. system would tend to oscillate.

An increase in servo amplifier gain. increases system response. reduces tendency to hunt. reduces the speed of the system.

The term "velocity lag" refers to. a speed error. acceleration error. position error.

The rotor of an AC tachogenerator. rotates at constant speed. has skewed slots. has a copper, brass or aluminium cylinder.

A servo system with transient negative velocity feedback. is damped with little velocity lag. is underdamped with high velocity lag. is damped with high velocity lag.

To reverse the direction of rotation of a two phase induction motor. reverse the polarity of both the control phase and reference phase. reverse the polarity of the control phase. shift the reference by 90°.

Loss of DC to a servo amplifier causes the motor to. reverse. stop. run continuously.

An AC servo demand can be converted to drive a DC motor by the introduction of a. rectifier. demodulator. modulator.

Synchro indicator systems are used when the indication is required to move. a fraction of the input distance. at the same rate as the input. slower than the input rate.

A piezoelectric crystal is an example of an analogue transducer. a Pneumatic Transducer. a Electro Acoustic Transducer. an analogue transducer. a Pneumatic Transducer. a Electro Acoustic Transducer.

The difference between an open and closed loop is. error signal. feedback. correspondence.

In a Desynn indicator system, where is power supplied to?. Transmitter and indicator. Indicator only. Transmitter only.

What does the Desynn indicator rotor consist of?. Electro magnet. Permanent Magnet. Aluminium cored coil.

The phase difference between the supplies of a two phase induction motor is. 90°. 180°. 0°.

If the rotor of the receiver in a torque synchro system was prevented from aligning with the transmitter rotor, then. the transmitter rotor will turn to align with the receiver rotor. the receiver will hunt. the receiver will overheat.

An E&I bar output at datum has. an imbalance of voltages in the secondary windings. no induced voltage in the secondary windings. equal and opposite voltages induced in the secondary.

If the rotor of a control synchro sticks. the system hunts. the position feedback will oscillate. high current will flow.

With the reversal of the connections to the rotor of the transmitter of a torque synchro, the position of the receiver rotor will be. changed by 120°. unchanged. changed by 180°.

The application of a "stick-off" voltage to a control synchro servo system is. to overcome the effect of static friction. to overcome the effect of viscous friction. to prevent alignment to a false null.

A servo system may include a brake, an automatic trim system is one example where a brake is used. The brake is. applied when trimming is complete to prevent stabilizer creep. applied during trimming to prevent oscillations about the demand position. applied during trimming to prevent servo runaway.

In a control synchro the stator current ceases to flow when. the CT rotor is at null. when power is removed. when the two rotors are aligned.

The result of reversing the rotor connections to the receiver of a torque synchro system is that the rotor position. is changed by 180°. is unchanged. is changed by 120°.

A hysteresis servo motor is used in a servomechanism because. it has good starting characteristics. good speed/voltage relationship. low inertia.

With a constant input to a speed control servo, the servo motor. moves to a certain position. moves at a constant speed. oscillates, but otherwise does not move.

Critical damping in a servomechanism is. the point which allows just one overshoot before the load comes to rest. the amount of damping that results in the load just not oscillating. the critical damping required for the optimum damping of the servomechanism.

Reverse rotation of a control transformer rotor can be caused by. connections to the transmitter rotor reversed. connections between the transformer rotor and the amplifier reversed. short circuit between two transmission lines.

A two phase motor will stop when. the control phase is reversed. the reference phase is reversed. the control phase is zero.

The term "velocity lag" refers to a. speed error. acceleration error. position error.

The rotor of an AC tachogenerator. rotates at constant speed. has skewed slots. has a copper, brass or aluminium cylinder.

A servo system with transient negative velocity feedback. is damped with little velocity lag. is underdamped with high velocity lag. is damped with high velocity lag.

Loss of DC to a servo amplifier causes the motor to. reverse. stop. run continuously.

A linear variable differential transformer is used to measure position feedback where. an output whose phase is related to direction of movement and amplitude linear over a wide range. 360° of rotation and high angular accuracy is required. is of limited importance but robust construction and reliability is important.

A low frequency sinusoidal input will cause a closed loop servomechanism load to. move to a demand position with no overshoot. move backwards and forwards at the input frequency. move to a demand position with overshoot.

If a servo amplifier is suffering from drift. the load would move to a new position, proportional to the drift and then return back to the datum position. the load would move to a new position, proportional to the drift and stay there. the load would oscillate about the datum position.

In a transient velocity feedback circuit, the tachogenerator output is summated with the demand voltage. at all times when the load is moving. only when the load is speeding up or slowing down. only when the load is slowing down.

An LVDT has. an output winding which is wound in series opposition. an input winding whose voltage will change with load movement. an output winding whose voltage and frequency is linear to load angular movement.

To convert a differential synchro from subtraction to addition you would. change over two rotor and two stator connections. change over all three stator windings. reverse the reference phase supply.

In general the accuracy of a synchro system increases if the. stator current is low. rotor current is high. stator current is high.

The induced signal in the output coils of the magnesyn system. de-saturates the soft iron core. is of a value of 800 Hz. damps the pointer oscillations.

The direction of the induced (secondary) magnetic field in a synchro transmitter. in the same direction as the primary field. is in the opposite direction to the primary field. is 90° to the primary magnetic field.

The cogging effect in synchros is rectified by. using an elliptical cog. skewing the rotor. using carbon brushes.

Reversal of the power supply to either the transmitter or the receiver of a torque synchro system would. make the receiver rotor rotate in the opposite direction. cause a 180° displacement between the transmitter and the receiver. have no effect on the indication, but would cause a heavy current to flow.

The purpose of a flywheel incorporated in a synchro is to. increase the driving force. prevent insect ingress. prevent oscillations.