The BK Precision 1670A220V Triple-Output DC Power Supply, 30V/3A, 12V/0.5A, 5V/0.5A, 220VAC Line Input includes constant voltage and constant current operation modes. Protections include current limiting, reverse polarity, overvoltage, and short circuit. Since each output is fully isolated, any output can be connected for positive or negative polarity. The main output voltage and current are continuously monitored by two digital LCD meters with resolution of 0.1 volt and 0.01 amp.