Design of an Inexpensive GPIB Interfaced Voltage Source

An inexpensive voltage source that can be controlled by a computer using the general purpose interface bus (GPIB) controller is designed since commercially available GPIB interfaced voltage sources are very expensive. The designed voltage source has been tested for regulation and compared with two commercial type power supplies. The power supply of the voltage source was constructed using the switch mode power supply (SMPS) method. Controlling the duty cycle of the pulse width modulator circuit the output voltage of the SMPS was regulated. PICmicroreg 16F877A microcontroller was used to control all operations of the GPIB interfaced voltage source