Sensors

Engine and Transmission

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Delphi Flat Response Knock Sensor

The Delphi Flat Response Knock Sensor is a self-generating piezoelectric sensor. Commonly mounted on an engine block or cylinder head, it produces an output voltage in proportion to the engine vibrations caused by knock. When knock is present on the sensor signal, the engine control module (ECM) controls knock by retarding spark timing, or diesel injection timing.

Benefits

Self-generating piezoelectric design requires no power to the sensor
Flat frequency response allows the same senor to be used on different engines and the sensor responds to knock frequencies higher than the primary frequency
Ground-isolated design with two-wire shielded harness helps protect the sensor signal from electro-magnetic interference (EMI)
Large mounting hole accommodates mounting bolts up to 10 mm in diameter

Typical Applications

The Delphi Flat Response Knock Sensor is designed for use on virtually any internal combustion engine, including:

Two stroke engines
Alternative fuel engines
Diesel engines
Flexible fuel engines

Performance Advantages

The Delphi Flat Response Knock Sensor has a flat frequency response over a range of from 1 to 18 kHz, thus the same sensor can be used on different engines by simply adjusting the filter frequency of the signal processing electronics to match the knock frequency of the engine. In addition, the sensor responds to knock frequencies higher than the primary knock frequency. This allows the higher knock frequencies to be used by a control system, either individually or combined with the primary knock frequency.

Performance Specifications

Voltage output	Average output 27 ± 10 mV/g over 1 to 18 kHz into a 100 K Ohm resistive load
Linearity	Output stays within a ± 15 percent of average value at the limits of 1 to 18 kHz
Mounting hole	Accommodates mounting bolts up to 10 mm in diameter
Operating temperature range	-40° C to 150° C
Environment	Sensor and connector are sealed to withstand humidity, salt spray, automotive fluids, and general automotive environments
Electrical connectors	Various harness lengths, alternative connectors, or connector at sensor body can be accommodated
Package size	A: Available in sizes of 29.8 mm and 25 mm B: Available in sizes of 24.35 mm and 20 mm

Typical Installation and Behavior

This chart demonstrates the range of dimensions that can be accommodated with the Delphi Flat Response Knock Sensor mounting bolt.

Typical Transfer Function Axial Input Only

This chart demonstrates the behavior of the Delphi Flat Response Knock Sensor throughout the range of frequencies from 1 to 18 kHz

The Delphi Advantage
Delphi has one of the industry’s most complete portfolios of sensors. Delphi has the experience and the expertise to provide extremely reliable, highly accurate and very cost competitive sensors for a wide range of applications. And, Delphi can provide a single component or a multifunctional "smart" module to meet specific customer needs.

As a global leader in engine and powertrain management systems technology, Delphi can help manufacturers around the world meet emissions requirements, improve fuel economy and enhance performance. Delphi is a source for high value solutions and our systems expertise is built into every product. Delphi’s flexible engineering approach encourages collaboration. And, Delphi has a thorough understanding of automotive markets around the world and a global network of resources.

Delphi Flat Response Knock Sensor (197k)