TDK Lambda EMS 250-20-2-D Power Supply

The TDK Lambda EMS 250-20-2-D Power Supply has an input AC voltage that can rectify and filter to process a high unregulated DC voltage. The unregulated high DC voltage will be changed later by the inverter (A200 Bd.) in a square wave of high recurrence. This waveform may be stepped up or down by a high recurrence isolation transformer. The auxiliary output is rectified and filtered to produce the required low ripple output voltage. The output dims down and contrasts with a reference voltage, consequently regulating the output. Regulation is achieved through the modulation of the pulse width created toward the control phase (A100 Bd.)

The AC input enters through TB2 on the back of the unit. It passes through the power line filter on the A300 board. The purpose of the Power Line Filter is to attenuate high frequency conducted emanations produced inside the unit, thus reducing the high frequency current emitted onto the power source. The load side of the line filter connects to a DPDT switch, which permits power to pass through the rectifier span to supply the DC bus capacitors C1 and C2. During the turn on, the contact of K1 will be in the open position, restricting the inrush current through the rectifiers. Then, after a delay from 3 to 4 seconds, the contact shuts, permitting ordinary power exchange.

If you would like more details about the specifications and functions of this model, the user manual is available on the ApexWaves.com website.