The VAC 16-132-304 12V AC Brick™ is designed to function properly with an input power of 11-13V AC. The Brick will not operate from a DC voltage.
A 2.1mm P5 style connector is used for the power input. If the input voltage is a grounded system, the center pin of the P5 is the power connection and the barrel is the ground side.
All ProSeries units are shipped with a 12V AC, 600mA floating power supply that eliminates any ground loops through the power supply connection.
This unit has a very basic linear power supply with a 12 VAC input voltage requirement. A 12 VAC wall transformer (120 VAC input) is supplied with each unit. By using the wall transformer the power system provides ground isolation between the input power and the video circuits. The power supply uses a half wave rectifier design to develop the internal positive and negative voltage rails for the active operational amplifiers.