Our address:

FRIWO Gerätebau GmbH
Von-Liebig-Straße 11
D-48346 Ostbevern

Tel. +49 25 32 81 0
Fax +49 25 32 81 112




Temperature of the stationary air surrounding the device. Is usually measured ca. 10mm beside the device in operation.

Battery types

Li-Ion = Lithium Ions

LiFePO4 = Lithium iron-phosphate

NiCd = Nickel Cadmium

NiMH = Nickel Metal hydride

Pb = Lead

Class B

Protection against electronic shock taking special account of the leakage current.

Class BF

Same as Class B, however, taking into account the so-called „F parts“,  which can occasionally come into account with patients and are isolated from all other parts.

Class CF

Class with the highest level of protection.

Continuous short-circuit proof

Continuous short-circuit proof means that a short circuit can be permanently active, without the output being damaged. If the error is fixed, the output will once again function normally.


Abbrevation for desktop.


The efficiency is calculated from the ratio between power output and input and it is always remains lower that one.


Abbreviation for Electronic Manufacturing Services (Contract manufacturing).


Abbreviation for electromagnetic compatibility. EMC is the ability of an electrical appliance to operate satisfactorily in its electromagnetic environment without adversely affecting this environment, which may also contain other equipment. Power supply units should comply with at least two generic standards for EMC:

1. The interference transmission standards ( interferences which the power supply unit emits by cable or through the air) and

2. Immunity standard (protection against interferences from outside).

These generic standards encompass a number of further sub-norms which set limit values for each strand (e.g. certain types of interference). FRIWO power supplies meet these standards even tighter than required since we believe that the EMV of our devices should be as good as possible to guarantee a trouble-free service.


Abbreviation for Global Power Plug.

Leakage current

A current that flows through the ground when a device is in operation. It flows above capacity and the insulation resistance of an operating circuit over the protective ground conductor of a device.


Abbreviation for Light Emitting Diode.

Life expectancy

Operating life of a power supply. At the end of their life, power supply units are increasingly likely to fail because components are worn out.


Abbreviation for Multi Power Plug.


MTBF stands for Mean Time Between Failures (Average time between two consecutive device failures). The MTBF indicates when a device fails on average due to processing or component defects before signs of wear set in.


A temperature-resistant resistor with negative coefficient, whereby the resistance values greatly reduce with increasing temperature. Therefore it is also called a thermistor. It serves not only to measure temperature but also to limit the inrush currents of power supply units.


Abbreviation for Open Frame.

Operating temperature

The temperature range, which the temperature must not be exceed or fall below when an appliance in operation.

Overvoltage protection

A circuit in the power supply monitors the output voltage. If a certain preset limit is exceeded the power supply is deactivated.


Electronic overload protection which limits the maximum output current to a preset value.


Abbreviation for Power Plug.

Short circuit proof

Short circuit proof means that a temporary short circuit of some can be absorbed without any damages.

Single range

Power supplies with input voltage for usage inthe corresponding countries.


Abbreviation for Surface-Mount Device.


SMT (surface-mount technology) is a technology, whereby the surface-mount devices (devices without wire leads) are directly soldered onto the PCB by means of solderable pads.

Standby losses

Power requirements of a power supply in idle mode.

Storage temperature

Temperature range in which a device may be stored (not operated) without causing damage.


Stands for the English term through-hole technology and describes through-hole mounting. In this type of mounting, the components have wire leads (“wired components”) and are pushed through the PCB using contact holes in order to connect them through special THT-soldering processes afterwards.


Abbreviation for flush mounting.


Abbreviation for Universal Serial Bus.

Voltage control

A control loop in the power supply unit keeps the output voltage constant, regardless of all factors. (e.g. temperature).

Wide range

Wide range power supplies can be operated at different nominal/rated voltages without having tobe readjusted (manually or automatically) by a switch.