Selecting the right connector depends on thoroughly understanding the end-use application. Here, members of Rutronik’s technical support team, Ronny Gölz, and Albert Culetto, provide an overview of current connector developments.
In conjunction with the internet of things, smart manufacturing, also known as Industry 4.0, is a major driver for technological development. Just like the internet of things, it is based on connectivity, which relies on connectors, although the products required here must be sufficiently robust for industrial use. In this way, Industry 4.0 is not just a driver for growth, but also for technological progress, delivering a multitude of innovations that also benefit other sectors.
Almost all applications in machinery, manufacturing and automation are subject to extreme conditions such as damp, dust, oil, chemicals, high temperatures and vibration. Plant safety is also crucial. Many manufacturers have responded to these demands by developing connectors that conform to various standards and offer IP67 or IP68 protection. This is particularly true for M8 and M12 connector types frequently used in industrial applications, as well as modular jacks and USB.
Molex offers an extensive portfolio of robust solutions, including its sealed connectors series, which comprises standard and custom sealed connectors of different protection classes. Note that the protection class applies only to the connected condition; as soon as the connection is open, protection is generally no longer assured.
In addition to safety and environmental considerations, flexibility and compact design are also drivers in this sector. For example, in-cabinet automation components mostly feature connectors for single-wire connection because they enable flexible connection of sensors, actuators and the power supply. Likewise, in power electronics, developers are turning to circuit board connectors in place of clamped solutions because they permit more compact and flexible equipment designs, as well as delivering high current carrying capacity.
Industrial standard connectors such as RJ45 and round plug connectors are also becoming more widespread for data connections, because field bus systems are increasingly being replaced by Industrial Ethernet. Fibre-optic connectors allow fast, interference-free transfer of large data volumes.
Another sector driven by safety and the quest for increasingly robust connections is automotive. Other core requirements in this sector are space and weight saving, with some manufacturers already offering systems with more than 300 contacts. High-performance alloys such as CuNiSi also improve current carrying capacity, facilitating smaller solutions, while materials like aluminium and copper alloys save on weight.
As an example, JAE has developed the MX19 series specially for the automotive sector. These small wire-to-wire connectors are certified as waterproof to JIS D0203 S1 and can withstand temperatures between -40 and 105°C, as well as the typical vibration that occurs in vehicles. Thanks to its grommet with backward sealing, the MX19 series is designed to optimise harness assembly layout, with terminals fitting better in the enclosure. The seal protects against damage, cable flapping and water incursion, while the terminals feature a double-plate spring mechanism with a long carrier length for low insertion forces and pressure dispersion.
Manufacturing for e-mobility
Sticking with the transport theme, e-mobility has prompted many new developments. Hybrid and electric vehicles have introduced new voltage and current classes with significantly higher temperatures and vibration levels. Electric powered vehicles are particularly at risk from environmental influences such as water, dust, dirt, oil, chemicals or electromagnetic fields and consequently, demands on the design, base materials and contact surfaces of any connectors are more stringent. No standard has yet become established and OEMs are mainly applying custom solutions.
When it comes to the charger unit, however, things are different. OEMs have established various standards: type one, mainly in America and Japan, type two in Europe and GB/T in China.
Specifically, Amphenol has developed its PowerLok high-voltage, high-current connection system to meet the requirements of chargers and cable assembly for hybrid and electric vehicles. Based on radial socket contact technology, it is designed to ensure less voltage drop and temperature rise, enlarging the surface area thanks to its radial design. PowerLok connectors are rated for 750A and 1,000V and feature high voltage interlock current protection.
This automatic interlock ensures terminals are optimally positioned and provides sufficient holding force even for rough environments. Its various groove options help eliminate the risk of faulty connection and it makes the typical clicking noise popular in the automotive industry. Not only that, this simple connection is said to guarantee maximum protection for the user because if the lock is opened, the high currents are immediately cut.
Continuing the high-current theme, Amphenol also offers a connector series for energy storage devices, specially designed for high-current connections in the battery module and in the battery management system itself. The Radlok family includes a series of plug designs that can be used both inside the battery, as a cell-to-cell connection, and externally, as a battery-to-battery or array-to-power store connection. It boasts low insertion and removal forces and a high number of plugging cycles thanks to its integrated locking and unlocking mechanism. Maximum current capacity is 750A, with maximum DC voltage of 1,000V and a temperature range from -40 to 125°C.
On track for rail developments
In the rail sector, demand for connectors is rising due to the increased deployment of Ethernet networks for applications such as cameras and displays, and due to the trend toward modular train design. Subsystems must be easily connected to route power, data and signals through all the on-board units.
For outdoor use, connectors not only have to withstand vibration and shock impact, but also all kinds of weather conditions. These applications therefore demand IP68 or IP69K protection and mechanical interlocks. In the train’s interior, lesser protection is sufficient, though electromagnetic fields play a greater role, often addressed using shielded connectors. In addition to this, all connectors must conform to railway standards, which differ from country to country. They normally include high resistance to hydraulic fluid, aggressive cleaning agents and similar substances.
Lighting the way
Connector requirements for LED lighting can be difficult to specify as they vary according to location and application. In general, the more robust the solution, the broader its application. The SSL-1 series from Amphenol, for example, features shock and vibration proofing to EN 61373 and is suitable for indoor and outdoor LED applications, as well as for the transportation market. The series comprises board-to-board, wire-to-board and wire-to-wire connectors, eliminating soldering and thereby delivering shorter surface mount production times and reduced costs. It is also said to take up less space on the PCB, making more room for greater LED density.
Medical connector technology must first and foremost conform to industry standards and licensing requirements governing shielding, leak-tightness, autoclavability and touch protection. Other frequent stipulations include high contact security and large numbers of plugging cycles, as well as protection against disinfectants and aggressive cleaning solutions.
Connection systems that meet these high demands usually entail complex production processes. Moreover, their development costs are often not yet amortised through mass production. That can make them relatively expensive, so they are not suitable for cost-sensitive applications, or where the protection offered is not actually necessary.