Emerson MPR25, MPR15 Series user manual Operation, Rectifier operation

21

Operation

Rectifier operation

The main AC line voltage is rectified and filtered to an unregulated high DC voltage. The input circuit provides EMI filtering, inrush current limiting, low and high AC inhibition, lightning and surge voltage protection, and input fault protection through an AC breaker.

The high frequency isolating power section consists of a full bridge converter using power MOSFETs and a high frequency power transformer.

The high frequency AC voltage generated at the secondary of the power transformer is rectified and filtered. The output section provides EMI filtering, a shunt for output DC current sense, and output protection in the form of a DC breaker. A current mode pulse width regulator varies the pulse width of the signal driving the power MOSFETs. This allows regulation to the output DC voltage.

The monitoring circuitry includes soft start, rectifier fail alarm (RFA), rectifier RFA/ON LED, local and remote equalize, temporary release, thermal shutdown, AC valid, local and remote high voltage shut down (HVSD), local and remote HVSD reset, logic valid, fan failure detection, and a fan failure LED.

A three-digit output current meter reads the output shunt and displays the value using an integrated logic circuit.

An auxiliary power supply provides the various voltages required by the internal circuitry and cooling fan.

25A Switch Mode Rectifier NT5C06B / C Installation and User Manual