Comparison between AC and DC servo systems : Sr. No. AC servo systems DC servo systems 1. Efficiency is low Efficiency is high 2. Low power output High power output 3. It requires less maintenance It requires frequent maintenance 4. Less stability problems More stability problems. 5. Smooth operation Noisy operation. 6. It has non-linear characteristic It has linear characteristic Comparison between AC and DC servo systems Video: Comparison of stepper motor with DC servo motor Basics of Multiplexing HOW MOBILE NETWORK WORKS WITH GMSK MODULATION TECHNIQUE ? Comparison in FDM and synchronus TDM and statistical TDM How Multiplexing of signals in Fiber Optical cable