Stabiliser
Since the arrival of switched-mode power supply in IT and Telecom equipment, stabilisers are used less frequently than 20 years ago. One key characteristic of a switched-mode power supply is its extremely small dimensions which is of vital importance for the PC industry which wants to make equipment as compact as possible. In addition switched-mode supply is not sensitive to voltage variances of up to 35% of the nominal voltage. One drawback is that switched-mode supply does not fully buffer high-frequency grid contamination.
Voltage stabilisers are mainly still necessary for linear power supply, lighting equipment, motors, etc. and only in those places where voltage levels can still vary strongly.
Several variants or principles are available.
Line - conditioner based on 50 Herz transformer which reaches "saturation", exclusively suitable for protecting 50 Herz-based power flows against voltage variances. Only available for small power capacities up to 2000VA.
Line - conditioner based on electronic step-up or step-down transformer. A principle that is also found in the transformer of a Line-interactive UPS where the term buck and boost is used. This is no more than a transformer, usually with a number of windings on the secondary side, which can be electronically switched on and off so that the outgoing secondary voltage variances are limited in the event of primary voltage fluctuations.
Motor-controlled voltage stabiliser, an instrument measures the delivered voltage and, if variations occur, a motor is started up which shifts a contactor on the transformer winding so that the output voltage is brought back to the nominal level. A small deceleration in the reaction is present but this is usually acceptable for the application. Available in small to very large power capacities both in phase 1 and phase 3.
The Power conditioner appeared on the market when switched-mode power supply became commonplace in IT equipment. The power conditioner does not stabilise the mains voltage. This, after all, is not necessary as the switched-mode power supply is not in itself sensitive to this. The power conditioner has an extremely low impedance so that the frequency spectrum being used by a switched-mode power supply is effortlessly allowed through by the power conditioner. The power conditioner protects the switched-mode power supply against those phenomena which can affect it such as high-frequency voltage contamination between 5KHz and 5MHz. In addition, the power conditioner also provides optimal protection against peak load and indirect lightning strikes.
