ALPS ELECTRIC EUROPE GmbH has developed the “SPVQC Series” Surface Mount Two-Pole Sliding Contact Micro Switch1.
Advancements in applying electronics to automobiles have brought about an increase in vehicles equipped with electric parking brakes (EPB), particularly in the United States, Europe and Korea. Such devices have to achieve a high degree of safety and methods for system backup, such as the duplication of circuits, are generally incorporated into the mechanism as a fail-safe2 measure.
Until now, backup in EPBs has been achieved using two micro switches, but this has led to problems such as the on/off timing of the switches going out of sync during low-speed operation. Moreover, when employing a butt contact structure, as is often the case with weak currents, contact faults have occurred due to ingress of particulates or other matter.
In addition, surface mount components are increasingly used for LEDs and other components around the EPB device, requiring that micro switches are capable of undergoing reflow soldering together with these components during assembly by the customer.
ALPS has now developed the “SPVQC Series” Surface Mount Two-Pole Sliding Contact Micro Switch. The company’s existing SPVQ9 Series was the first such switch in the industry to employ a two-circuit sliding contact structure and has been well received by customers, capturing more than a 50% share3 of the European market. Retaining the same structure as the existing product, the SPVQC Series surface mount switch ensures high contact reliability with strong resistance to particulates, as well as to vibrations and impact. ALPS also applied its mechanical engineering and precision processing technologies to overhaul the design of the internal mechanism, thereby reducing the product’s width by 1mm.
The SPVQC Series employs a double-sided sliding contact structure consisting of a moving contact that clamps a fixed contact from both sides. This enables application of a constant pressure on the contact at all stages of the switch operation from the moment the pressing begins, through on/off switching, to the fully depressed position. Combined with a snap action design, the structure constantly maintains a stable contact regardless of the control position and speed, making the SPVQC Series a highly reliable control switch.
The timing of switching between the two circuits is short, below 15ms at any control speed, the same as for the existing SPVQ9 Series. This enables configuration of a fail-safe system for a device with a single switch, contributing to cost reductions in device design and space savings.
The SPVQC Series achieves IP674 dust and water resistance.