Speed and temperature sensor
Description
Function of the speed sensor is to detect the shaft speed and the direction of rotation. Typically the
sensor will be mounted to the housing of a Danfoss pump or motor and senses the speed from a target
ring that is rotating inside the pump or motor. Because of the digital output signals for speed and
direction and a non speed dependent output voltage level, the sensor is ideal for high and low speed
measurements.
For diagnostics and other purposes, the sensor also has the capability to detect the case oil temperature.
The speed sensor is designed for rugged outdoor, mobile or heavy industrial speed sensing applications.
The detection of the speed is contactless. It is custom-designed for Danfoss. It is a “Plug and Perform”
device that does not need any calibration or adjustments.
Theory of operation
The speed sensor is externally powered and, in response to the speed of the target ring, outputs a digital
pulse signal. A magnet inside the sensor provides the magnetic field that changes with the position of
the target teeth. The target ring is attached to the cylinder block or the shaft. Hall sensors change from
high/low state as the target teeth pass by the sensor´s face. The digital (on-off-on-off) pulse train is fed to
a controller, which interprets its rate of change as a speed. The speed sensor uses two Hall sensors with
specific distance and orientation resulting in a pulse train output shift of 90° between the two sensors. A
logic circuit decodes the two signals to provide an additional direction indication (high or low depending
on direction). Due to the design of the sensor, the duty cycle (ratio between on and off time at constant
speed) of both speed signals at any working condition is close to 50 % and can be used for better
resolution at low speeds.
Speed (target) rings
Speed (target) rings vary according to the diameter of the cylinder block or shaft on which they are
installed. The number of teeth is shown in the table below:
The number of speed (target) ring teeth
Size
045/053
060/068
069/078
089/100
115/130
147/165
210/250
Teeth
79
92
86
86
102
108
90
Speed sensor technical data
Parameter
Min.
Nom.
Max.
Supply
4.75 V
DC
5 V
DC
5.25 V
DC
Supply protection
–
–
30 V
DC
Max. required supply current
–
–
25 mA
Output mode
NPN and PNP
Connector terminal
DTM04–6P (Series 6-Pin)
4
3 2 1
5 6
P006035
Pinout:
1 Speed signal 2
2 Direction signal
3 Speed signal 1
4 Supply
5 Ground
6 Temperature
Protection code IP-class
IP 67 and IP 69k according to IEC 60529 & DIN 40050
For more information, see
Speed and Temperature Sensor Technical Information
,
Basic Information
H1 Axial Piston Pumps, Single and Tandem
Operation
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©
Danfoss | April 2017
11062168 | BC00000057en-US0602
