A Synchro Transmitter Is Connected To A Synchro Receiver

Synchro Transmitter Connected to a Synchro Receiver: A Deep Dive into Functionality and Applications

Synchros, also known as synchro systems or self-synchronous systems, are electromechanical devices used for transmitting angular position information. They consist of a transmitter and a receiver (or control transformer), working in tandem to accurately replicate the angular position of a rotating shaft. This article delves into the intricate relationship between a synchro transmitter and receiver, exploring their operational principles, applications, and the advantages they offer in various industrial settings.

Understanding Synchro Transmitters and Receivers

A synchro transmitter is essentially a rotary transformer that generates a three-phase AC voltage whose amplitude and phase relationship precisely reflect the angular position of its rotor. The rotor's rotation causes a corresponding change in the output voltage, acting as an electrical representation of the mechanical angle.

A synchro receiver, on the other hand, receives the three-phase AC voltage from the transmitter. Its rotor aligns itself to an angle that corresponds to the voltage received, thereby mimicking the rotational position of the transmitter's rotor. This precise mirroring of the angular position forms the basis of synchro system functionality.

Core Components and Operational Principles

Both synchro transmitters and receivers share a similar construction:

• Stator: Composed of three separate windings (usually denoted as A, B, and C) distributed around the stator's circumference. These windings are physically displaced by 120 degrees.
• Rotor: A single winding located in the center of the stator. The rotor's rotation relative to the stator windings determines the output voltage characteristics.

When a voltage is applied to the rotor of the transmitter, the interaction between the rotor and stator windings generates a three-phase voltage output that's directly proportional to the rotor's angular position. This output is then transmitted to the receiver's stator windings. The receiver's rotor, free to rotate, aligns itself to match the magnetic field generated by the received voltages, achieving angular position replication.

The Interconnection and Signal Transmission

The connection between the synchro transmitter and receiver is straightforward, involving the three stator windings (A, B, C) and the rotor windings. The corresponding windings are directly connected: transmitter stator A to receiver stator A, transmitter stator B to receiver stator B, and transmitter stator C to receiver stator C. The rotor winding of the transmitter is connected to an AC excitation voltage source, typically 115VAC, 400Hz or 26VAC, 400Hz. The receiver's rotor winding is usually connected to a load or an indicator device.

It's crucial to maintain correct wiring and polarity to ensure accurate angular position replication. Incorrect wiring can lead to inaccuracies and potentially damage the devices.

Types of Synchro Systems

Several types of synchro systems exist, each designed for specific applications:

1. Transmitter-Receiver Systems:

These are the most basic type, discussed above. They are suitable for simple angular position indication and replication.

2. Transmitter-Control Transformer (CT) Systems:

In these systems, a control transformer (CT) replaces the receiver. The CT doesn't have a freely rotating rotor; instead, it's used to detect the difference in angle between the transmitter and a manually-adjusted control. This configuration is commonly used in servo systems for error detection.

3. Differential Synchro Systems:

These systems employ a differential synchro as the receiver. A differential synchro sums or subtracts the angular positions from multiple transmitters, providing the combined angular position or angular difference. This is useful in applications requiring precise angular calculations.

Applications of Synchro Transmitter and Receiver Systems

Synchro systems find applications in diverse industries, including:

• Aerospace: Indicating aircraft instrument positions, such as the position of a control surface or the angle of attack. Accuracy and reliability are paramount in these applications.
• Marine Navigation: Displaying heading and other navigational data. Robustness and resistance to harsh environmental conditions are critical in maritime applications.
• Industrial Automation: Controlling the position of robotic arms, conveyor belts, and other machinery requiring precise angular control.
• Military Equipment: Precise targeting systems, weapon pointing, and other critical applications. High accuracy and reliability are essential.
• Simulation and Training: Simulating the motion of various systems, such as aircraft flight simulators.
• Process Control: Monitoring and controlling the position of valves, actuators, and other industrial process components.

Advantages of Using Synchro Systems

Synchro systems offer several advantages:

• Simplicity: Relatively simple design and construction, making them easy to understand and maintain.
• Robustness: Durable and capable of withstanding harsh environmental conditions.
• Accuracy: Provides reasonably high angular accuracy, particularly crucial in precision applications.
• Cost-effectiveness: Generally less expensive than other comparable angular position sensing technologies.
• Direct Mechanical Analog: Provides a direct mechanical analog to the electrical signal, simplifying the interface with mechanical systems.

Limitations of Synchro Systems

Despite their advantages, synchro systems have limitations:

• Limited Resolution: Compared to modern digital systems, synchros have limited angular resolution.
• Susceptibility to Noise: The analog nature of synchros makes them susceptible to electrical noise, potentially affecting accuracy.
• Maintenance: While generally robust, synchros require periodic maintenance and lubrication.
• Weight and Size: Compared to modern digital encoders, synchros can be relatively bulky and heavy, limiting their applicability in some space-constrained applications.
• Power Consumption: Synchros consume power continuously, even when static.

Modern Alternatives and the Future of Synchro Technology

While synchros remain relevant in many legacy systems and specific applications, modern technologies, such as digital encoders (rotary encoders, optical encoders, magnetic encoders), are increasingly replacing them. Digital encoders offer higher resolution, better noise immunity, and improved signal processing capabilities.

However, synchros' inherent simplicity, robustness, and relatively low cost still make them a viable choice in certain applications where high precision isn't critical and cost-effectiveness is prioritized. In the future, we might see continued use of synchros in specialized applications, particularly those where their inherent advantages outweigh the limitations of the technology. Further advancements might focus on improving their accuracy, resolution, and power efficiency, potentially extending their longevity in specific industrial niches.

Conclusion

The synchro transmitter and receiver system represents a fundamental electromechanical technology for transmitting angular position information. While facing competition from more modern technologies, it continues to hold relevance due to its simplicity, robustness, and relatively low cost. Understanding the operational principles, advantages, limitations, and applications of these systems is crucial for engineers and technicians working in fields where precise angular position control and indication are required. The ongoing evolution of this technology ensures its continued presence, albeit perhaps in a more niche capacity, within various industrial sectors.