Applications include transducer amplifiers, dc amplification blocks, and all the conventional operational-amplifier circuits that now can be more easily implemented in single-supply-voltage systems.

This letter introduced application of servo technology for horizontal pillow packaging machine and it's for modern food industry comparing with the conventional motor control and transducer control.

To avoid shortcomings of conventional current transducers in insulation and saturation, the hybrid optical sensor head of a new type air core current transducer is presented.