What is the advantage of relay type than servo type AVR?

Relay-type Automatic Voltage Regulators (AVRs) are typically simpler and more cost-effective than servo-type AVRs. They provide faster response times to voltage fluctuations by using electromechanical relays to switch taps on a transformer, which can be beneficial in applications where quick adjustments are needed. However, they may offer less precision and smoothness in voltage regulation compared to servo-type AVRs, which use motors for more gradual adjustments. Overall, relay-type AVRs are advantageous for their lower cost and rapid response in less demanding applications.