The 57C494 is a 23-amp Power Supply that can be mounted into an AutoMax card rack assembly.  While there may be a few types of power supplies you can choose from, a power supply is a mandatory component in a rack assembly. This device supplies power to all of the other devices on the rack using the backplane. This power supply takes up two slots on the rack and must be plugged into the far-left side of the rack. It is plugged directly into a series of card slots on the backplane of the rack and then secured into place using screws and the mounting brackets on the rack and power supply. This system has an input of 120VAC 50/60HZ. It has the ability to convert that input current and turn it into a DC current. It has an output of +5 VDC 20A, +15 VDC 75mA, -15 VDC 75mA, +12 VDC 1A, or -12 VDC 1A.  This system features an over-current/over-voltage protection.