A throttle position sensor (TPS) is a sensor used to monitor the air intake of an engine. The sensor is usually located on the

butterfly Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...

spindle/shaft, so that it can directly monitor the position of the throttle. More advanced forms of the sensor are also used. For example, an extra "closed throttle position sensor" (CTPS) may be employed to indicate that the throttle is completely closed. Some

engine control unit An engine control unit (ECU), also commonly called an engine control module (ECM), is a type of electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. It does this by ...

s (ECUs) also control the throttle position by electronic throttle control (ETC) or " drive by wire" systems, and if that is done, the position sensor is used in a

feedback loop Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...

to enable that control. Related to the TPS are accelerator pedal sensors, which often include a wide open throttle (WOT) sensor. The accelerator pedal sensors are used in electronic throttle control or " drive by wire" systems, and the most common use of a wide open throttle sensor is for the kick-down function on

automatic transmission An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission (mechanics), transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gea ...

s. Modern day sensors are non contact type. These modern non contact TPS include Hall effect sensors,

inductive sensor An inductive sensor is a device that uses the principle of electromagnetic induction to detect or measure objects. An inductor develops a magnetic field when a current flows through it; alternatively, a current will flow through a circuit contain ...

magnetoresistive Magnetoresistance is the tendency of a material (often ferromagnetic) to change the value of its electrical resistance in an externally-applied magnetic field. There are a variety of effects that can be called magnetoresistance. Some occur in bu ...

and others. In the potentiometric type sensors, a multi-finger metal brush/rake is in contact with a resistive strip,Garrick, R.D., Sensitivity of Contact Electronic Throttle Control Sensor to Control System Variation, Society of Automotive Engineers (SAE) Technical Paper, 2006-01-0763, April 2006. while the butterfly valve is turned from the lower mechanical stop (minimum air position) to WOT, there is a change in the resistance and this change in resistance is given as the input to the ECU. Non contact type TPS work on the principle of

Hall effect The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor that is transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current. It was disc ...

or inductive sensors, or magnetoresistive technologies, wherein generally the magnet or inductive loop is the dynamic part which is mounted on the butterfly valve throttle spindle/shaft gear and the sensor & signal processing circuit board is mounted within the ETC gear box cover and is stationary. When the magnet/inductive loop mounted on the spindle which is rotated from the lower mechanical stop to WOT, there is a change in the magnetic field for the sensor. The change in the magnetic field is sensed by the sensor and the voltage generated is given as the input to the ECU. Normally a two pole

rare-earth magnet Rare-earth magnets are strong permanent magnets made from alloys of rare-earth elements. Developed in the 1970s and 1980s, rare-earth magnets are the strongest type of permanent magnets made, producing significantly stronger magnetic fields than ...

is used for the TPS due to their high

Curie temperature In physics and materials science, the Curie temperature (''T''C), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties, which can (in most cases) be replaced by induced magnetism. The Cu ...

s required in the under-hood vehicle environment. The magnet may be of diametrical type, ring type, rectangular or segment type. The magnet is defined to have a certain magnetic field that does not vary significantly with time or temperature.

Notes

{{DEFAULTSORT:Throttle Position Sensor Engine sensors

See also

Notes