This paper presents a design of the control system to control AC/DC converter. Algorithm of a control system design consists of the output voltage loop control used a fuzzy gain scheduling of PI control and the current loop control used a hysteresis control which is described in this paper. The evaluation of the proposed control system is used to control an isolated CUK AC/DC converter operation with a 250W load and a -48V output voltage. The system is achieved as the following; the tight output voltage both the steady state operation and the transient response a power factor is nearly unity and the waveform of input current is nearly sinusoidal. In addition the control system design is simple and uncomplicated

This research is to study and develop a DC motor speed control by using Visual Basic.Net 2008 in computer programming to use the computer and the microcontroller is processing from computer via the serial port. So that a signal to the motor driver circuit motor speed work as assigned. By the speed can be entered via the computer screen is measured in rpm. and motor control to control the PWM (Pulse Width Modulation) control circuit and the principles of the hardware by using the digital output signal of the microcontroller control Motor speed can be configured to be from 100 to 3000 rpm. And the motor starts to spin at maximum speed and then gradually reduce the speed down to the specified value. Control both the speed and the average error of 4.6% compared to the speed measurement using infrared light. And found that at speeds below 100 rpm. to a maximum error of 12% and the error decreases when the speed increases. The error value is at least 2000 rpm. and 3000 rpm the speed error is 0.5%