In order to solve the HVDC bus voltage measurement parameters,the output analog voltage signal of DC voltage transformer was turned into pulse-frequency signals by High-precision V/F converter,which go through the optical transmitter module,optical fiber and optical receiver modules to achieve the function of pulse frequency signal optical transmission.

The paper discusses the accuracy offset when using the timer to sample periodical signals in common A/D transform circuit composed of V/F converter,and proposes an improved circuit which adopts pre- positve signal regulation to makes the change of input signals consistent with that of the period of output signals.

In order to improve the precision of north-seeker,the signal collection and processing system based on V/F conversion is designed.

This paper mainly describes the method of the high-accuracy temperature measurement system using high-accuracy temperature sensor AD590 and LMX31 series V/F conversion chip.

Such a novel algorithm for implementing A/D conversion using a V/F conversion chip is presented.

In this paper, a methodbased on V/F transformationis introduced to measure the hysteresis loss for ring-shaped sample,The principle and structure are intrduced.

The threshold voltage is set by output channel comprised of pulse generator,photoelectric coupler and F/V converter,and the detection result is input through photoelectric coupler.