Implementation of an Electromagnetic Vibrator for Precision Seed Sowing Machine

Metering device employing electromagnetic vibration for seed sowing machine has many advantages. A electromagnetic vibrating system featuring a specially designed V-grooved vibrating metering pan, a digitally controllable power supply to a solenoid to accomplish vibration control. This paper discusses the design of its electrical control system. A relatively high voltage ac input (50v) is inverted to dc voltage using switching inversion mode to improve efficiency, which is then chopped to provide pulsed exciting source to the solenoid . Both the inversion_and the chopping_are governed by a microcontroller and therefore a pulse train with frequency and amplitude digitally variable (4~100Hz, 3-50v) is obtained to drive the solenoid . Adjustment is made via four keys and is monitored by a numeric display screen. Practical applications show that this device is very convenient in vibrating system design as well as tuning . Some experimental test results are also included in this paper.