Over the years, the aerospace industry has seen the introduction of modern electronics with increasingly lower voltages into aircraft. Along with these lower power requirements came the expectations of much higher life cycle requirements and a more compact packaging of components. This is a problem for traditional electro-mechanical pressure switches which have struggled to meet these new requirements.
The problem is traditional electro-mechanical pressure switches use integral micro-switches with inherent contact resistance and operating mechanisms that limit their performance and ability to meet the low-current, small size, and long-life specifications commonly required by today’s aircraft engineers. Increasing contact resistance alone can cause the micro-switch to fail rendering the pressure switch inoperable. This contact resistance can lead to contact degradation which, in turn, causes the switch’s mechanical linkage to wear during operation. This can cause set point drift and lead to eventual failure, typically within just 350,000 cycles of operation when the current trend in specifications now require at least 1,000,000 cycles.
To combat the problems found in traditional electro-mechanical pressure switches while meeting the new requirements of modern aircraft, Custom Control Sensors created the 7TRG-Series electronic pressure switch. This electronic pressure switch integrates a thin-film sensing element that functions like a traditional electro-mechanical pressure switch while using a proprietary galvanic isolation to extend the maximum VDC capability of typical thin-film based sensors from 500 VDC dielectric to 1500 VDC dielectric. This patent-pending isolation is exclusive to CCS switches and unique in the aerospace industry. The 7TRG-Series electronic pressure switch also uses electronic elements to produce the “on” and “off” switching. Because it does not have a micro-switch, the 7TRG-Series switch eliminates the problems of electrical contact degradation and high contact resistance completely. The electronic switching elements also eliminate the moving parts associated with mechanical electrical switching. The elimination of problems associated with electrical contacts and mechanical wear provide significantly increased switch reliability and an extended switch life. The galvanic isolation prevents the degrading effects from lightning by completely isolating the electrical component and interface from the grounded case.
Traditional electro-mechanical pressure switches provide an accuracy reading of +/- 5%. Changing the electrical switching to solid state provides an extra +/- 2.5% accuracy and a faster response time than an electro-mechanical switch. The electronic switch requires an excitation voltage between 10 to 32 VDC and switch currents as low as 3 mA. The operating temperature range is -67°F to 257°F (-55°C to 125°C). The 7TRG-Series electronic pressure switch can operate with pressures from 0 to 5800 PSIG (higher pressure ranges available). It also has an adjustable dead-band.
The CCS 7TRG-Series electronic pressure switch exceeds 1,000,000 cycles in high-pressure dynamic environments. With a smaller footprint and package size than an electro-mechanical switch, the electronic pressure switch is ideal for aerospace applications. The 7TRG-Series is more accurate, reliable, adjustable, and faster than traditional pressure switches. The features and benefits of the patent-pending technology CCS has developed provide the perfect solution to meet the specifications required by the aerospace industry and aircraft engineers.
CCS has been developing pressure, temperature and flow sensing products for over 60 years. As an engineering and technology-driven company, developing 7TRG-Series further solidifies CCS’ commitment to being a leader within the aerospace industry.