This paper presents the results of tests to study the energy efficiency of air conditioners Split 9000 BTU test the air in normal operation and when the tune parts. of Evaporator units use DC power from solar energy. Power of the test in normal operating conditions the air power and average about 820 watts on system configuration and operation of Evaporator units. 645 air watts average power consumption can be reduced up to 175 watts of electricity equivalent to 21.34% of them compare the energy efficiency of the air conditioner from the label number 5 on the test. The energy efficiency of a 14.41 11.55 a 24.76% increase in energy efficiency

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%