Bicker provides power supply for retail safety

Wanzl is responding to this with innovative access systems and has developed the barrier-free ‘SlidingDoor’ access gate with automatic sliding doors. To ensure reliable operation even in the event of a power failure, a compact and maintenance-free emergency power supply was required. It needed to be easily integrated into the system and meet the highest standards of durability and safety.

The ‘SlidingDoor’ was specially developed by Wanzl for modern entrance and exit areas and offers an ideal solution for companies with high security and convenience requirements. With the independent opening and closing mechanism of the sliding doors, access areas can be restricted or flows of people can be controlled effectively and barrier-free.

The system is well suited for retail applications such as shop areas, self-service checkouts, company entrances and fitness centres. The ‘SlidingDoor’ is equipped with state-of-the-art drive technology and is available with an emergency opening function in the event of a power failure or fire.

The ‘SlidingDoor’ drives are supplied with 24V by an upstream AC/DC power supply unit. A sudden power failure – whether due to a technical defect or in the event of a fire – can result in the door remaining closed and escape routes being blocked. In an emergency, this could jeopardise the safety of people in the building.

In order to guarantee safe passage in any situation, the system developers at Wanzl searched for an uninterruptible power supply (UPS) that would ensure that the door opens reliably at the crucial moment and that the escape route remains permanently unblocked. To achieve this, sufficient energy must be available in the UPS buffer storage at all times to ensure that the door opens safely. In regular operation, the drive requires a current of 2.3A, while 5A peak must be available at short notice during the safety test.

The solution not only had to be able to be integrated into the existing system in a space-saving manner, but also offer maintenance-free, long-term stable energy storage technology. Traditional battery solutions were therefore out of the question.

With Bicker Elektronik, the system developers at Wanzl found not only a power supply specialist and technology partner, but also the optimal solution for the uninterrupted 24V DC emergency power supply of the 'SlidingDoor' system. The customised DC UPS module BICKER UPSIC-2403-B3 with Supercaps as energy storage.

Thanks to the high cycle stability of up to 500,000 charging and discharging cycles, the maintenance-free ultracapacitors (so-called Supercaps) offer an exceptionally long service life and require no maintenance. Furthermore, the energy storage unit is charged and ready for use within a very short time.

Due to their compact dimensions and high power density, the DC UPS modules can be integrated in a space-saving manner. One UPSIC-2403-B3 from Bicker Elektronik is installed in each of the two columns of the 'SlidingDoor'. The specially customised B3 variant reliably provides the peak power required for the safety check after assembly, installation or repair of the access gate.

In normal operation, the charging and control electronics of the DC UPS forwards the input voltage to the output with a minimal reduction, charges the Supercaps and monitors the voltage thresholds at the input. If the voltage falls below the defined threshold voltage, the UPSIC-2403-B3 switches to backup operation within a split second and ensures an uninterrupted and regulated 24VDC power supply at the output.

The ‘SlidingDoor’ is operated in an ambient temperature range of +5°C to +50°C. However, the UPSIC-2403-B3 is designed for a significantly wider operating temperature range of -20°C to +70°C. It therefore surpasses the temperature requirements of the Wanzl system significantly and offers additional system reserves for long-term use thanks to its high-quality components.

For uninterruptible DC power supplies, maintenance-free Supercaps are available as highly efficient and particularly long-lasting energy storage devices for short and medium bridging times with up to 500,000 charge and discharge cycles. In contrast to batteries, which store energy via a chemical reaction, Supercaps are based on the electrophysical principles of the double-layer capacitor (EDLC) and are charged and ready for use within a very short time. Using comparable operating conditions, Supercaps have a service life up to 10 times longer than classic lead-acid batteries.

"We are pleased with the successful collaboration with Bicker, which has resulted in an optimal solution for our SlidingDoor. This partnership combines our expertise in access solutions with Bicker‘s energy management know-how and sets new standards in reliability and sustainability," said Marcel Engelmohr, Global Product Manager Access at Wanzl.