Objective:In Order to study on biological effects of rotary magnetic field (RMF) conveniently and precisely

a digital-controlled instrument for generating RMF

which is based on a single-chip microcomputer

is developed.Methods:The precise frequency of RMF is controlled by using microcomputer to drive step motor

and intensity of magnetic field is measured by using 10-bit Analog-to-Digital(A/D) Converter module which is integrated in microcomputer.According

the technique of LCD screen to display relative information

such as

frequency

intensity of magnetic field

time of timer

is applied.Additionally

touching buttons

which is simple and convenience to use

is selected.Results:This instrument works very well with high precise frequency

and its operation is simple.As a example for this instrument

that biological effect of RMF on the the prostate about SD rat is significantly is found.Conclusion:This instrument may be used to research and study on biological effects of RMF widely.