Phase-locked Loop Servo Systems

Phase-locked Loop Servo Systems

Updated by: Kaylee

On: 06 Nop, 2017

Viewed:1,155 times - 17 hour, 46 minute, 40 second ago

Downloaded: 0 times -

Category: Circuit


Rated 3.1 / 5 based on 309 reviews

Phase-locked Loop Servo Systems is a closed-loop control system that is used widely in communication systems for frequency demodulation and bit synchronization. Phase-locked loop servos are also use for velocity control, especially when a high deg...

Phase-locked Loop Servo Systems is a closed-loop control system that is used widely in communication systems for frequency demodulation and bit synchronization. Phase-locked loop servos are also use for velocity control, especially when a high degree of speed regulation and accuracy is desired.

A phase-locked loop in its basic form is represented by the block diagram of Fig. 37. The input signal and the feedback signal are sinusoidal and upon locking both signals will have the same frequency and a constant phase difference. Any deviation from the desired phase difference is detected by the phase detector and is transmitted to the vo;tage-controlled oscillator (VCO) to correct the error. Since the phase difference is constant, the frequencies of the input and the feedback signals are the same. This principle can be applied to servo systems for which the control objective is speed regulation.

In the case of a phase-locked loop servo for speed control, the VCO is replaced by an amplifier-motor-encodercombination. The output of the encoder is a sinusoidal signal with a frequency proportional to the angular velocity of the motor. Fig. 38 shows the block diagram of a phase-locked loop servo.

The main difference between a phase-locked servo and the conventional servo systemis that the reference input for a phase-locked servo is a periodic signal from the encoder is a pulse train whose frequency is proportional to the speed of the motor. The phase detector compares the frequencies or phase of the reference and feedback signals, and generates an error voltage proportional to the difference. The error voltage is than filtered and sent to the motor, the motor speed changes to reduce the difference between the frequencies or phases of the two signals. Thus the motor speed can be syncronized to the reference frequency.

Related Posts

Simple, sensitive metal detector

The metal detecting hobby is enjoying quite a boom at the moment and treasure h...


Single Transistor Circuit


Note by Colin Mitchell: The first part of this discussion is a very old article using US imperial measurements, by Charles D. Rakes. A table of wire gauges is provided at the end of the article. Th...

Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if ...

Audio Tone Control Using The TLC074 Operational Amplifier

This application report describes the design and function of a stereo high-fidelity tone control using a single TLC074 quad operational amplifier. A rail-to-rail operational amplifier is used to pr...

Stereo Sound Controller IC BA3853BFS

The BA3853BFS is a dual-channel electronic volume controller built around a low-noise, low-distortion VCA. It is suited for car-audio applications, and has performance that rivals mechanical-type v...

As the fastest growing demand of circuit and wiring diagram for automotive and electronics on internet based on different uses such as electronic hobbyists, students, technicians and engineers than we decided to provide free circuit and wiring diagram base on your needed.

To find circuit and wiring diagram now a day its easy. E-learning through internet as a right place to search an exact circuit and wiring diagram of your choice and it's much fun and knowledgable. On internet you will find thousands of electronic circuit diagrams some are very good designed and some are not. So you have to modify them to make them according to your needs but some circuits are ready to make and require no changes.

There are many categories of circuit and wiring diagrams like automotive, audio circuits, radio & RF circuits, power supply circuits, light circuits, telephone circuits, timer circuits, battery charger circuits etc. There are many types of circuit and wiring diagrams some are very easy to build and some are very complicated, some are so small and some contain huge list of parts.

We provides free best quality and good designed schematic diagrams our diagrams are free to use for all electronic hobbyists, students, technicians and engineers. We also provides a full educational system to students new to electronics. If you are new to electronics you are a student or a electronic hobbyist and want to increase your knowledge in electronics or want to understand electronics in a very easy way so this is the right place for you we provide electronics beginner guide tutorials to easily understand complicated electronic theory. Our mission is to help students and professionals in their field.