The PD-A/AD Series power supplies are DC constant-voltage (CV)? constant-current (CC) power supplies with variable output level featuring the use of the phase control method and high reliability. Inheriting the reliability and accuracy of the highly approved PD Series and incorporating a wide variety of protection facilities? the PD-A/AD Series power supplies have been designed with emphasis on the ease of operation and safety in use as research and experiment power supplies or long aging system power supplies. With 9 combinations of different voltage/current capacity values and the meter indication type and digital indication type models available for each of them? a total of 18 models offer a wide variation which can be selected according to applications.