To set the DRB unit for parallel operation, simply set the front panel switch to “parallel”. The power supplies use a droop mode current share method to balance the load currents. Note, only units with the same model number can be paralleled. Up to three units can be directly connected in parallel to deliver more power. If more than three units are paralleled, precautions must be taken to avoid current flowing back into a power supply during a fault condition. This can be achieved using an ORing diode, FET or redundancy module (the TDK-Lambda DRM40 for example) in series with each positive output. This technique can be also used for redundant operation.