Top 10 switches and relays

One of the biggest trends in the switch and relay markets is the call for more options to help designers select the best switching device for their application. Other big asks are for longer life, smaller packages, and greater ruggedness.

A lot of these switches, especially electromechanical devices, need to operate in extreme environments and are subjected to dirt, dust, shock, and vibration. You’ll find that many of these devices can withstand these harsh environments and still offer long cycle life.

In addition, many switch makers are focused on delivering more illumination options for product differentiation while making it easier to design the parts into applications. For relay makers, there is a big push to shrink the size of these devices while improving performance.

Here is a selection of switches and relays, introduced over the past year, that offer more options while meeting growing requirements for longer life and smaller footprints in a range of applications that often operate under tough environmental conditions.

Switches

Switches come in a variety of types, including pushbutton, rocker, tactile, and toggle. They are found in just about every type of electronic equipment, from mobile devices, computers, and home appliances to medical devices, automotive, and instrumentation. Some of the biggest trends, depending on the application, include illumination, miniaturization, and extended life cycles. Switch makers are also extending their existing product lines with more options to better fit the needs of the end application.

Delivering on more options and long life, E-Switch has introduced the TL6150 series of surface-mount tactile switches with three actuation forces that provide up to a 5 million–cycle life. The series is rated for IP67 for moisture and dust protection. These tact switches target a variety of applications, including audio/visual equipment, computer peripherals, computer electronics, medical equipment, telecommunication devices, and test and instrumentation equipment.

 

Housed in a 6.2-mm² footprint, the tactile switches feature a soft silicon actuator available in 3.50- and 5.20-mm heights with gull-wing or J-lead termination options. The contact arrangement is SPST Off-(On).

Key specs include a 12-VDC, 50-mA contact rating and dielectric strength of 250 VAC for one minute. It also provides a contact resistance of 100 mΩ (max. initial) and insulation resistance of 10 MΩ @ 100 VDC. These switches operate over an industrial operating temperature range of –40˚C to 85˚C.

The three actuation force options are indicated by actuator color: brown (160 gf ±50 gf, 5 million cycles), red (200 gf ±50 gf, 500,000 cycles), and orange (350 gf ±100 gf, 300,000 cycles. Travel varies with force: 0.3 mm (160 gf), 0.35 mm (200 gf), and 0.5 mm (350 gf).

Also delivering long-life–cycle tactile switches is C&K. One of the company’s most recent examples is the PTS125 series of tactile switches that come with new options, including up to 5 million actuation cycles. Up from 200,000 cycles, the PTS125 series now delivers versions with 1 million and 5 million actuation cycles. The tactile switch series measures 12 × 12 mm and can be used in consumer products, instrumentation, and computing equipment.

The tactile switch family offers multiple options for actuation force (130, 180, 250, and 350 gf) as well as through-hole and surface-mount options. The SPST-NO PTS125 series offers a selection of heights (4.3, 7.3, 8.5, and 12 mm) and additional snap-fit actuators. The entire line features IP40 dust sealing, ratings of 50 mA @ 12 VDC, and an operating temperature range of –40˚C to 85˚C. The switch line is available in standard sizes that make it an easy replacement for competitive parts, said C&K.

Like C&K, many switch manufacturers are also expanding some of their popular switch lines with new options. Another example is EAO’s Series 82 pushbutton switch line, which now offers an overmolded option and M12 connector. The new version is available for selected illuminated pushbuttons in the Series 82. Illuminated versions are available with red, green, white, or blue LEDs.

The switches offer complete front and rear IP67 protection for harsh operating environments. Examples include in the food and beverage industry, where alkaline cleaning agents and corrosion severely affect HMIs, said EAO. The overmolded version can also operate in heavy-duty and special-vehicle applications, where switches can be subjected to hard-to-remove dirt, fine dust, severe vibrations, and blunt impacts.

These Series 82 illuminated pushbuttons feature a housing made from SUS 316L stainless steel and a Tritan light guide that is resistant to cleaning agents. These design features provide protection against wear and ensure consistent clarity of both the dot and the ring illumination, said EAO.

Alps Alpine Co., Ltd. recently launched its SSCZ series of single-pole/double-throw (SPDT) compact detector switches, expanding its switch series lineup for open/shut detection in car doors and trunks and other automotive applications. The new detector switch, a modified version of the existing SSCW (single-pole/single-throw) series, allows for the detection of two states — locked and unlocked — by using an SPDT design.

The series features double-sided sliding contacts to ensure high contact reliability even when subjected to impacts or vibrations, said Alps Alpine. The company also made some changes to the internal structure, enabling a 300,000-cycle operating life, which is 3× longer than the existing model. It also offers mounting compatibility with the existing SSCW switches.

The SSCZ switches measure 5.3 × 13.84 × 15.4 mm. They target automotive applications that require smaller and lighter detector switches and growing automotive safety features. Key specs include contact resistance of 500 mΩ (max.), an operating force of 1.1 N (max.), and an operating temperature range of –45˚C to 85˚C.

NKK Switches has expanded its popular KP04 series of long-life illuminated pushbutton switches with a surface-mount option. These switches can be mounted on a printed circuit board (PCB) with minimal drilling. The switches feature twin contacts with gold plating that ensure high reliability and long life of 3 million operations minimum. The switches offer a compact design with a height of 0.906 inches (23.0 mm) from the PCB to the top of the cap.

The RGB LED offers a full color spectrum in unlimited color combinations, said NKK. In addition, the RGB with the white option helps reduce variations in color tones for white illumination to deliver consistent color. Applications include broadcasting/audio/video equipment, automated systems, and communications equipment.

The flat, sculptured, or home key square caps are available in three common sizes, and the actuation options include non-tactile or tactile/audible. The actuation is synchronized with contact timing, delivering color simultaneously when actuating the switch. Nominal operating force is 1.6 N ± 0.6 N. Custom legends are available.

Schurter has added RGB ring illumination to its TTS touchless switch series. The TTS series provides contactless switching, highly precise operation, and now customizable colors in addition to its existing bi-color (green and red) options. Laser lettering and symbols are available for further customization.

The TTS switches, packaged in a stainless-steel housing, use optical time-of-flight sensor technology for precise programming of the devices. The standard detection distance is 20–60 mm. The minimum setting allows for wiping or cleaning of the switch surface without triggering a switching operation.

The TTS provides a service life of more than 20 million switching cycles. These switches offer shock protection of IK06 and an ingress protection rating of IP67 and can withstand splashes, drips, rain, or sunlight. It is also vandal-resistant.

The TTS RGB is available in momentary or latching versions. Switching current and voltage maximum are 100 mA @ 42 VAC/60 VDC.

The TTS switches can be used wherever contact should be avoided, said Schurter. This includes applications such as switches used to open automatic doors in public transportation and airports, as well as sanitary applications such as public restrooms, parking, and ticketing. The switches can also be used as a photoelectric barrier.

Relays

Like switches, relays are available in several flavors, including general-purpose, power, and reed as well as contactors, which are designed to handle very high current and voltages and solid-state devices.

For high-reliability applications, relay manufacturers are boosting the performance of their reed relays. “Reed relays offer a compact and lightweight solution for switching of AC or DC signals,” said Teledyne Relays. “Contacts are hermetically sealed inside a glass envelope, which protects them from corrosion. Compared with other mechanical-based relays, reed relays offer low power consumption, low contact capacitance, and faster switching speeds.”

Teledyne Relays introduced four new reed relay product families over the past year, targeting high-reliability applications with extremely long life of up to 1 billion cycles. Each of the reed relay product families are optimized for different applications that require high voltage, high isolation, and enhanced shielding from electromagnetic interference.

These include single-in-line (SIL) and dual-in-line (DIL) packaged parts, which contain one or more reed switches and an electromagnet, encapsulated in thermoset plastic. They are packaged for easy solderability to a PCB or inserted into sockets for easy replacement.

The new HVR series relays are designed for high-voltage/high-power applications and can switch up to 7.5 kV, 1.5 kW, while the HIR series, which offers up to 3-kV isolation between coil and contacts for applications, targets applications that require high isolation.

The MCR series relays offers metal shielding. Options include shielding to protect contacts from external interference from other nearby relays and components or to isolate contacts from electrostatic interference coming from the coil circuit, said Teledyne. Applications for the new products include radar, telecommunications, automated test equipment, dielectric voltage testing/hipot testing, ESD sensitivity testing, and power protection circuits.

Pickering Electronics has released a new high-voltage reed relay with significantly higher current-carrying capability. The new Series 67 range of dry reed relays delivers a standoff voltage of up to 8 kV and is capable of 6-kV switching with a power rating of 200 W. Series 67 is the highest power switch in the Pickering portfolio.

The Series 67 relays are constructed using a leadframe in an SIL format and feature former-less coils, which results in a smaller package size. The relays also feature long-life tungsten contacts, which, in combination with the higher power and high current-carrying capabilities, enables the devices to be used in high-performance applications. Applications include mining/gas analysis, big physics, high-end cable testers, backplane testers, and high-voltage instrumentation.

The relays withstand shock to 50-g and 20-g vibration (10–2,000 Hz). The operating temperature range is –20˚C to 85˚C.

The Series 67 dry reed relays feature PCB connections to both switch and coil. Supplied in 1 Form A and 1 Form C configurations, the relays are available with 5-, 12-, and 24-V coils with an optional internal diode. Other voltage ratings can be supplied as special orders.

Targeting harsh environments, TE Connectivity has expanded its existing MS27418 relay series with the CII FCC-325 relay, with the added benefits of auxiliary contacts. The 2-A SPDT auxiliary contacts can be used to perform additional functions related to the control of the relay, said the company. This includes allowing for circuit-trip feedback status, illuminating an indicator light, and other similar control functions.

The CII FCC-325 relay meets performance standards of MIL-PRF-6016, supporting harsh inductive, motor, and lamp load applications in the military and commercial aerospace, defense, and marine markets.

TE Connectivity said it had to carefully consider the environments that the relays have to operate in, ranging from 400-Hz aerospace power to 50-/60-Hz ground power systems. Applications for these relays include launch systems, navigation systems, weapons systems, and naval equipment.

The FCC-325 relay is a non-latching, hermetically sealed relay for 25-A resistive loads and offers 28-VDC or 115-VAC coils. The relay can operate in high-shock (50 g/11 ms) and -vibration (10 g/5 to 1,000 Hz) environments. The operating temperature range is –70˚C to 125˚C.

Dielectric strength at sea level is 1,250 Vrms coil to case and 1,500 Vrms for all other points. Dielectric strength at 80,000 feet (25,000 meters) is 500 Vrms (all points).

Omron Corp. designed the G9KA high-power PCB relay with ultra-low contact resistance to help improve energy efficiency. The relay is said to improve the efficiency of PV generation systems by minimizing energy loss caused by the heat generated by power conditioners, power supply equipment, and related equipment used in solar-power generation systems.

The ultra-low contact resistance of 0.2 mΩ (initial contact resistance value under the condition of 200 A, 30 minutes) suppresses the heat generated by the relay, improving the power-generation efficiency of solar-power generation systems and accelerating renewable-energy deployment, said Omron.

“One of the factors that can cause the [power generation] equipment to generate heat is the relays mounted on the PC board inside the equipment,” reported Omron. “Relays are components used for executing on/off control of the electric current flowing through the equipment when linked with the power system and for safety shutoff in an emergency. Conventional high-power relays have a high contact-resistance value, so energy loss due to heat generation has been an issue.”

Omron also noted that heat-dissipation solutions like heat sinks and cooling fans have been used as countermeasures against heat generation, and there have been cases where PCBs have deteriorated due to the heat generated by the relay, impacting the longevity of equipment.

According to Omron, the G9KA can reduce the temperature rise of the relay by about 30% by lowering the contact resistance to 0.2 mΩ compared with conventional high-power relays. It also helps to reduce the size and weight of the equipment by simplifying the cooling solutions needed to dissipate the heat.

The G9KA, capable of energizing and de-energizing 200 A (800 VAC), can be used in equipment where large loads need to be cut off, said Omron. It can also replace contactors that are primarily used for high-capacity power control applications, with about a one-third reduction in height for space savings. The relay measures 51 × 51 × 47.2 mm.

In addition to power conditioners for industrial solar-power generation, the G9KA relay can be used in EV quick chargers, robot control equipment, storage batteries, and industrial air conditioners.