Height-adjustable pendant light

• What was needed: The stepper motor had to start up and slow down gently with every movement. The motor control had to adjust the height of the lamp and maintain the same distance to the height-adjustable table.
• Requirements: Reliable function, precise control, repeatability, durability
• Success for the customer: Reliable function, precise control and repeatability were achieved. The drylin® stepper motor executes the movements of the pendant light gently and quietly. The drylin® motor control unit communicates with the customer's control system and controls the motor to maintain a constant distance from the table.

The challenge is to develop a luminaire that is visually heavy and is only held in place by two thin steel cables. In addition, the luminaire is to be designed in such a way that it can communicate with a height-adjustable desk and thus maintain the previously set distance to the desk while being raised or lowered in synchronisation with the desk. This requires precise design and control technology as well as mechanisms for communication between the light and the height-adjustable element.

It is also important to achieve reliable function, durability and precise control. High repeatability is also very important, as the lamp will later move in synchronisation with the desk. The stepper motor must start up gently with every movement and also decelerate gently in order to keep the light stable in the balance. Otherwise there is a risk that the lamp will start to swing too much. The many motor control parameters were also an exciting challenge.

igus® offers solutions for the development of the luminaire that meet the requirements with its drive technology products. For the height adjustment control system, stepper motors were used in conjunction with a motor controller. This combination makes it possible to precisely control the movements of the luminaire and fulfil precise positioning requirements. The stepper motor, which is located on the ceiling, drives a shaft on which the two coils with the steel cables are located. The current is transmitted to the steel cables via sliding contact.

By integrating the stepper motor into the system, finely tuned height adjustment can be achieved while ensuring smooth operation. The versatile D1 was initially selected as the motor control unit for the prototype. When this was successfully tested, the more favourable D8 control system from igus® was offered as a replacement. In this way, the customer always received the most favourable solution that works! André also reports: "The support from igus® was very good and characterised by great enthusiasm. Problems were quickly identified and solved in interactive video conferences."

Here you can see exciting extracts from the creation process of the lamp and how it works in the end.

Operating the lamp is very simple. The user can initially choose between manual or automatic mode. In manual mode, the lamp is set to the desired distance from the table using a mini-microcontroller that acts as a remote control. If you then switch to automatic mode, the light follows the desk as it moves up or down. This means that the user always has perfect illumination at their workstation and does not have to readjust the light source manually.