Manufacturers of solid-state relays grow category

SSRs still have a minority share of China's relays production, but output is on steady rise. Development of photo MOSFET types has begun.

Solid-state relays continue to climb up the relays industry in China, representing about 20 percent of shipments now and outperforming the entire line in terms of sales growth in the past three years. The category posted an increase of more than 15 percent during the period compared with the overall local sector's 8 percent. This trend will persist as the product with its advantages of fast response, low power dissipation, high reliability and long life span is expected to replace traditional electromechanical types. Most makers anticipate the market will be bigger by 5 to 10 percent in the next one or two years.

At present, however, not all relays companies in China are turning out SSRs but those who do actively pursue development and production. Clion Electronic Co. Ltd bolstered output by 25 percent in 2016 and targets to implement over 10 percent increase by this year's end. SSRs account for 20 percent of its aggregate shipments.

Most suppliers ensure their releases have enhanced stability and reliability compliant with international standards. The last includes IEC 62314-2006, EN 1122B:2001 and EPA 3050B:1996, 3052:1996, 3060A:1996.

Besides work on standard solid-state kinds, some midsize and large makers have ventured into photo MOSFET units, saying the latter will become the best choice for buyers originally sourcing electromechanical types. They cite the adoption of optoelectronics in SSRs in recent years, which improves component performance.

Photo MOSFET relays are called such because they use LEDs and PV diode arrays as input devices for high isolation, and MOSFETs as output devices. These exhibit high sensitivity, quick response, low on-resistance and current leakage, enhanced isolation and no noise, in addition to being smaller as a result of this configuration. The kind is widely used in communications and medical equipment, consumer electronics, computers and peripherals, and industrial automation.

Beijing Ketong has released model JGW-3M photo MOS relay, which comes in a ceramic package measuring 7.57x4.32x0.01mm and is for use in the industrial control, scientific research and military fields. The unit has 3ms turn-on and 0.5ms turn-off times, and 10mA input current, 0.6V off voltage, 50 and 1.6A or 0.8A output and 1µA leakage current. Power dissipation is 0.8W.

Interviewed suppliers Excel Cell Electronic Co. Ltdand Forward Industrial Co. have optically isolated relays.

Over half of China's total SSR shipments, including from foreign companies there, are allocated for overseas markets, mainly the US, Europe, and East and Southeast Asia. By end-2017, the export volume will have increased by 5 to 10 percent. Clion will raise its outbound deliveries by 10 percent.

There are more than 200 manufacturers of solid-state relays in China, and at least 60 percent are local and mostly small and midsize enterprises.

The largest homegrown maker is Xiamen Hongfa and the other major ones include the Chint Group and Xinling Electrical. Omron, TE and Siemens are among their foreign counterparts with production bases there. All companies also offer electromagnetic relays and circuit breakers.

The provinces of Guangdong and Zhejiang are the key manufacturing hubs for SSRs in China. There are also factories in the north and central parts. Companies are anticipated to flock to the line as demand increases, and will likely set up bases in these locations.