DC Power Supply UnitsTechnical description:
These direct current power supply units are used chiefly for feeding control and signalling circuits. These devices are designed to DIN 19240 Pt 4.1 and meet the requirements laid down for power supply units for feeding electronic control systems.
The transformers used have separate windings and ± 5% taps on the primary side for matching to the mains voltage. Clearances and creepage distances as well as the test voltage conform to VDE 0570/IEC61558 so that safety circuits to VDE 0570/IEC61558 can be realized if suitable overloading and short-circuit protection measures are taken.
Connections are made to shockproof screw terminals which allow simultaneous or optional connection with flat connectors (up to 6.3 x 0.8). The current is rectified by a silicon bridge-connected rectifier. The residual ripple is 48% in the case of single-phase devices and about 5% for versions with filter capacitor.
The ripple is less than 5% for three-phase devices, even without filter capacitors. The DC voltage outputs are protected against overcurrent by means of varistors. It is, however, recommended that the kick-back voltages which occur with inductive loads at switch-off should be suppressed at the point of origin (e.g. by connecting a diode). The standard series of equipment is designed for 230 V or 3 x 400 V on the primary side and 24 VDC on the secondary side. Other voltages, power ratings, construction types and stabilized versions are available on request.