Burlington, WI-based NEL Frequency Controls, Inc. has been awarded a patent for its redundant clock module design. This frequency control solution is aimed at frequency sensing applications where monitor, detect and action functionality is required. This proprietary technology is available from NEL in either a module form factor or as a licensed technology.

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“We are very excited about the impact of this technology not only with system redundancy issues but also its broader application with smart sensors,” noted Chuck Ulland, vice president of sales and marketing at NEL Frequency Controls. “Frequency detection capability that is sensitive to slight signal change opens the door to a lot of smart system possibilities.”

One example of how this technology can be employed features a redundant clock module with two crystal-controlled (XO) oscillators, a phase detector, and a filter. Each oscillator has a control loop that monitors frequency output. If the oscillator runs at a higher or lower frequency or completely stops, the control loop filter quickly detects the irregularity in the signal. The module then switches to the operable oscillator within one output cycle, providing a glitch-free transition between clocks and preventing system failure.