Honeywell International Inc.

Paul Stevens

Dale A Trumbo

Alex Wedin

Tom G Mulera

Dave Faymon

Kevin Jones

David K Faymon

Mansoor Shah

A transient voltage suppression circuit includes a voltage suppression circuit, a switch activation circuit, and a solid-state switch. The switch activation circuit is configured to selectively supply a switch activation signal. The solid-state switch is electrically connected in series with the voltage suppression circuit, is coupled to receive the switch activation signal selectively supplied by the switch activation circuit, and is configured, in response to the switch activation signal, to switch from an OFF state to an ON state.

Switched transient voltage suppression circuit

Apparatus for protecting a signal line bus driver from overvoltage faults may include a first solid-state switch configured to block current having a positive voltage when open and a second solid-state switch configured to block current having a negative voltage when open. A comparator circuit may produce a output signal responsively to presence of a fault-induced voltage in the signal line that has a magnitude that exceeds the reference voltage. The first and second switches may be connected in series with one another and with the bus driver. The switches may be interposed between the bus driver and an output end of the signal line and may responsively to the comparator circuit output signal.

Appartus and method for protecting signal and communication lines from very high voltage and transient pulses

A low-side driver circuit includes a low-side driver integrated circuit and a controllable switch. The low-side driver integrated circuit is responsive to an on-off command input signal to selectively operate in an ON mode and an OFF mode. The controllable switch is responsive to the on-off command signal to selectively operate in a CLOSED mode and an OPEN mode. The low-side driver integrated circuit and the controllable switch are configured to simultaneously operate in the ON mode and the CLOSED mode, respectively, and in the OFF mode and the OPEN mode, respectively. During a voltage transient the potential will be realized across the controllable switch, thus protecting the lower voltage rated low-side integrated circuit.

Low-side driver high-voltage transient protection circuit

An electronic circuit measures a pulse frequency and/or a pulse period of pulses in a sensor signal originating in a sensor coil, the pulses being zero crossing pulses. The circuit includes a filter stage having an input connected to the sensor coil, the filter stage being for removing electrical noise from the sensor signal to provide a filtered sensor signal. The circuit also has a signal strength sensing circuit connected to receive at least one of the sensor signal and the filtered sensor signal, the signal strength sensing circuit producing a variable threshold signal, which is a substantially monotonically non-decreasing function of a strength of the sensor signal. A variable threshold zero crossing detector is connected to receive the filtered sensor signal and the variable threshold signal. The variable threshold zero crossing detector has an upper threshold to test for zero crossing in a positive direction and a lower threshold to test for zero crossing in a negative direction. One or both of the thresholds is dependent on the variable threshold signal. The variable threshold zero crossing detector generates a clean square-wave pulse train indicative of positive and negative zero crossings. The circuit also includes an output circuit generating a signal indicative of the pulse frequency and/or the pulse period.

Speed sensing system with automatic sensitivity adjustment

The broken shaft detection system and method uses a detector assembly mounted downstream of a power turbine wheel of a gas turbine engine to detect rearward axial motion of the wheel and thereby a broken shaft event. The detector assembly has a plunger positioned to be axially displaced against a link connected in an electrical circuit. The link may be broken when the plunger is displaced thereby creating an open circuit that may be detected by a detection and test element. The breaking may be communicated to an overspeed circuit that controls a shut off switch that interrupts fuel flow to the engine. The link may be connected to the detection and test element by two pairs of parallels wires to facilitate monitoring of circuit function and to detect failures that are not broken shaft event failures.

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Oro Valley, AZ, United States of America

Paul Stevens