The PK52 push button of TSL stands out within the Presskey family in terms of its external features: an extremely large touch surface, very good lateral recognition of the status display and an acoustic orientation signal. These are just a few examples that facilitate the awareness of TSL-ESCHA’s PK52 push buttons and greatly simplify safe operation. Braille and self-explanatory pictographs also support tactile and visual recognition. The improved operational characteristics are particularly helpful for passengers with reduced mobility in buses and trains.
The individual needs of door manufacturers and vehicle operators were also taken into account during development. Therefore, the PK52 is available in different variants. The most frequently selected version has a nominal voltage of 24 VDC with sound (2 to 5 kHz). A version with a nominal voltage of 12 to 24 VDC is available without sound.
Another variant of the PK52 can realize almost all functions and special requirements regarding light signals and sound signals (nominal voltage 24 to 110 VDC, with sound from 900 Hz to 5 kHz). All of these functions can be parameterized thanks to the integrated micro-controller. It is possible to display different light patterns that, help passengers with a red-green weakness perceive the light signals. First three red LEDs light up and then three green LEDs at another position. A 4:2 change is also possible. EN 14752 is fulfilled thanks to this change of position and color. The PK52 also meets the other criteria stipulated by this standard. Various switching functions allow the customer-specific composing of the PK52.
TSL also offers the additional function for the PK52 push button with a timer setting for the light signals, the so-called sandglass effect. When the door is released, the green LEDs light up. However, as soon as the push button is pressed, all red LEDs light up, which then turn off one after the other in a defined cycle. This happens while the gap bridging extends from the door to the platform and the door remains closed. This feature of the push button clearly indicates the waiting time to the passenger until the door opens.
PK52 also with plastic bezel and for installation in glass doors
PK52’s stainless steel front panel conceals the screws. This offers considerable advantages in many areas, such as preventing unauthorized persons from dismantling the push buttons. The powder-coated panel is available in various RAL colors so it can be harmonized with the vehicle design. To meet the changing requirements, a bezel made of high-quality plastic material was designed. This means the operator can choose from a larger variety and, if desired, also replace the stainless steel bezel of the PK52 push button (from year of manufacture 2016) with one made of engineering plastic.
The PK52 push button of TSL is also available for the installation in glass doors of buses and trains. The new variant with a spacer ring that adapts to different door profiles is available with double-sided function and single-sided function with a blind cover.
The PK52 can also be used as an emergency button, for example in lavatories, by combining it with a triangular plate. The TSL push button thus complies with the EN 16683 standard.