Abstract: A back-up device includes at least one back-up battery, in particular a rechargeable battery which can be charged via the power supply, and a control unit. The control unit connects the back-up battery when the actual value of the DC voltage is less than a predefined minimum value, generates a predefined back-up time period and disconnects the back-up battery again, cyclically, after this time period has elapsed. The device has the advantage that the return of the output DC voltage of the power supply can be identified effectively without major complexity. The loads continue to be supplied both in the event of a failure of the supplying input voltage and in the event of a failure of the power supply, since the output DC voltage, which is essential for the loads, of the power supply is monitored. The device can be connected additively downstream of a power supply, without any intervention in its design being necessary.

Abstract: The rot-resistant plant support which is aesthetically pleasing and can be inexpensively produced consists of a rod section and a plastics material which can be colored. The interior of the rod is finely porous while the surface zone has bark-like protuberances. The plant supports are manufactured by extrusion at processing temperatures in the tool adjusted to between 5 and 30.degree. C. above the temperatures conventionally employed for extruding foams with a smooth surface from the same thermoplasts.