D-Class Power Amplifiers - EN 54-16
Security Amplifiers, EN 54-16
The DPAfour250 is a 2U high 19” rack mountable, 4-channel class-D power amplifier, transformer isolated for 100 V, 70 V, 50 V and low-impedance distributed loudspeaker systems. Each amplifier can deliver up to 1000 Watt when used in bridged mode or in separate channels of 125 or 250 Watt.

This amplifier has a dual voltage mains 110/230 VAC and a 24 VDC battery back-up input which allows it to be used in combination with a battery backup system for maximum availability and durability in an emergency evacuation system. There are 3 types of power amplifiers available in the DPA four range of products.

•       DPA four 250: 4 x 250 Watt class-D power amplifier.
         It can be bridged into 2 x 500 W.
•       2U high, 19-inch rack mountable.
•       Quiescent curent in sleep mode: 30 mA.
•       Front panel indicators include:
•       General status: Power, Battery, Service and General Fault.
         Detailed status: Signal, Clip, Fault and Ready
        (Ready = out of sleep mode).
•       100 / 70 / 50 / 4 Ohm available via terminal blocks at the rear.
•       Output channels can be linked into 2 x 250 W or 2 x 500 W
        by daisy-chaining 50 V tapping (input on parallel).
•       Combines with the BECS150 charger and back-up supply.

At the rear of the DPA you will find:
•       Mains switch with fuse
•       Individual level adjusters
•       General fault contact (Dry contact)
•       Commercial use disabled contact
•       Lamp test input contact
The figure below shows a block diagram of DPAxx. The individual blocks described above are easily visible. On the standard unit the serial interface is not provided. The logic inputs and outputs are programmable.