OIS27
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OIS27 Redundant position sensor for hydraulic cylinders ________________ General Description OIS27 is a patented smart optical device, which is usually combined with a hydraulic steering cylinder. The main application is on rough terrain machines, to detect when the wheels are correctly aligned. The alignment occurs when the sensor detects a different refraction index zone, which is marked on the hydraulic cylinder’s rod. The product is based on reflective sensor as input stage, a computing unit (microprocessor device) and an output stage with high side driver, which is able to deliver up to 50mA. The sensor includes a lot of “smart” functions and special algorithms that allow to continuously adapt the device to the wear of the system during the time, improve the life of the system, guarantee the high reliability (MTTF = 145 years) and be able to work in the harsh environment (temperature variations, rod wear, presence of electromagnetic disturbs, presence of humidity, shocks and vibrations). Moreover this serie offers, in the same package of OIS21, a fully redundant sensor being able to ensure higher reliability performances.  Fully redundant structure  Unsensitive to EM noise  High MTTF : 145 years  Meets all ISO 7637-2 and ISO16750-2 requirements, Load Dump at max levels  Compact case (same as 1 channel device)  Smart interface and smart algorithm  IP67  Inversion of polarity and overload protections Steering machines Surface cleaning machines Rough terrain machines Road building machines Construction machines Agricultural machines Name VCC (white) GND (green) OUT2 (pink) OUT1(yellow) (yellow VCC (brown) GND (gray) Function Power Supply Ground Output 2 (PNP) Output 1 (PNP) 5V Power Supply Ground Logistic machines Loaders _______________ Ordering Information Output diagram, connector Amphenol AT04-6P-MM01 † Available only on request Rev. A; 11.2016 – OIS27.A; 2016/11/16 11.31.00

RELIABILITY PARAMETERS Symbol

OIS27 MECHANICAL DIMENSIONS The dimensions are expressed in mm, tolerance ±0.1mm. Figure 1 – Right angle versions OUTPUT CONFIGURATION Figure 2 – OIS27-12AT configuration, Amphenol AT04-6P-MM01 connector

Table 1 - Compliance table OIS27-12AT / Load Dump pulse and Cranking pulse only.

OIS27 Application circuits _________________________________________________________________Resistive load A typical output load is a lamp. For such resistive loads no precautions shall be taken: the output stage is protected against reverse of polarity, short circuit and temperature. The power absorbed by the output stage is equal to RDSON * Iload. Figure 3 – Resistive load connection and VOUT transition graph Inductive load_________________________________________________________________ Inductive loads are described by inductance L and resistance R. At switch ON, the inductive load...

In this case, depending on the supply voltage and on the time constant, there is a real risk to break the output stage of the sensor. The output stage is composed of a logic stage, a power mosfet and a zener diode: the diode protects the output against overvoltages. If the VDS of the output stage during the transitory becomes very high (double the Vcc value) for long period, it can destroy the mosfet or the zener protection diode inside the output stage. In order to avoid this possible situation, the use of a freewheeling diode in parallel to the load is recommended. Figure 6 - VOUT...

Load dump means the disconnection of a powered load. It can cause large voltage spikes from the inductive generator(s). In automotive electronics, it refers to the disconnection of the vehicle battery from the alternator while the battery is being charged. Due to such a disconnection of the battery, other loads connected to the alternator see a surge in power line. Load dump may occur as a result of cable corrosion, poor connection or of intentional disconnection with the engine running. The pulse shape and parameters for an alternator with no centralized load dump suppression (Chap. 4.6.4...