# Speed series

• • • • • • • # MJ-VR69 (CW & CCW) Dual-channel sensor

Brief Introduction

●  MJ-VR69 (CW & CCW) Dual-channel  sensor is installed on the shell of the measured machine, inducting the raised part or concave slots of the magnetizer, it shows the corresponding level, it is used to detect axis of rotation speed, linear velocity. The method to get the acceleration of the measured machine is by calculation processing. The sensor has good low and high frequen

cy characteristics. The low frequency is as low as 0Hz, can be used for zero-speed measurement of rotating machinery, because the sensor can provide a certain phase of two speed signals, so you can judge for CW or CCW; high frequency is as high as 20KHz, can meet the high-speed measurement requirements of vast majority of industrial field. It is contactless measurement between the sensor and the measured gear, no wearing and easy installation. The output waveform is square wave that duty cycle for about 50%.

●  Hall Dual-Channel Sensor has the features of great adaptability, wide speed range, wide temperature range and strong vibration resistance.

Working Principle

1. Speed measurement principle

When the speed gear rotates, the sensor will provide a frequency fHz= n×m/60 (n is the rotating speed, p is the gear teeth) of the square wave signal, It can be used for the locomotive electronic control system to do sampling detection of locomotive speed and diesel engine speed.

The inductor need to be a magnetizer, can be groove, raised screw or toothed gear.

There are several parameters as follow for using the sensor to do detection:

m -numbers of the inductors on the measured rotating magnetizer.

n -speed

f -input signal frequency

s-the set meter factor (depends on characteristics of the speed measuring instruments, some speed measuring instruments set gear teeth directly, please follow the manual of the speed measuring instrument you selected to set meter factor)

S=60/M  n = s ´ f = 60 ´ f / m

After setting the induction numbers of measurement system, the setting coefficient of the instrument can be made sure. According to the sensors in each channel that corresponding induction numbers to determine the coefficient of each channel.

For example, as to the speed measurement of a rotation axis, there are 30 gear teeth on the axis, it means the teeth numbers of induction Z = 30, then the output frequency of each channel f = (30/60)´n, rotating speed n = 2f, that means the measured frequency multiply 2 is equal to actual speed. Set the coefficient of speed measuring instrument in 2, means s = 2, then the actual speed of rotor can be displayed directly. Similarly, if every rotor produce 2 signals, then set the coefficient s = 30. Others can be deduced by analogy.

2. CW/CCW discrimination measuring principle

Hall Dual-Channel sensor can discriminate CW run and CCW run easily.

According to the application example in specification 4 to install it, when it runs CW as figure 4, the output wave of channel 1 is ahead of channel 2 90°. Waveform diagram is as follow:

When the direction of rotation is opposite to figure 4, the waveform of channel 2 is ahead of channel 1 90°. Waveform diagram is as follow:

From the above chart, we can do phase discrimination for the waveforms of channel 1 and channel 2, then to do reverse discrimination.

Dimensions and installation diagram

The follow diagram is the dimensions and installation diagram for Hall Dual-Channel Sensor.

Rz is the radius of gear, X is the distance from addendum to the surface of sensor (0.3≤X≤1.5).

One tachometer wheel with 60 gear teeth, mode number is 2, if the sensor is installed as figure 4,channel 1 is ahead of channel 2 and the phase difference is about 90 °.

If the mode number is not 2, push the sensor to some angle r when installing the sensor, you can also get the phase difference as about 90 °, shown as figure 5.

For more details, please call us, there are professionals will offer you to the professional solution for your specific conditions.

Installation, Usage and Fault handling

1. About SJ series Hall Dual-Channel Sensor, it is not allowed the working power supply connect with locomotive battery, it should connect with isolated power supply to output

2. The sensor output wire must be connected with no mistake according to the specification, make sure there is no short circuit and open circuit appears. Strictly prohibit pulse output and power supply to be short circuit.

3. Install the sensor according to the instructions in the installation diagram. After adjust the gap between the gear and head of sensor to 0.6mm, tighten it.

4. Before the sensor installed into the shell of measured machine, use a ferromagnetic contacts and leaves the sensor, if the output current changes, it is normal.

5. In normal condition, if the output current no changes, the sensor is damaged.

6. If the wire is damaged by external force, the solution is to change a sensor.

• Description
• Specifications
• Parameter selection
• Feature
• Inquiry

Brief Introduction

●  MJ-VR69 (CW & CCW) Dual-channel  sensor is installed on the shell of the measured machine, inducting the raised part or concave slots of the magnetizer, it shows the corresponding level, it is used to detect axis of rotation speed, linear velocity. The method to get the acceleration of the measured machine is by calculation processing. The sensor has good low and high frequen

cy characteristics. The low frequency is as low as 0Hz, can be used for zero-speed measurement of rotating machinery, because the sensor can provide a certain phase of two speed signals, so you can judge for CW or CCW; high frequency is as high as 20KHz, can meet the high-speed measurement requirements of vast majority of industrial field. It is contactless measurement between the sensor and the measured gear, no wearing and easy installation. The output waveform is square wave that duty cycle for about 50%.

●  Hall Dual-Channel Sensor has the features of great adaptability, wide speed range, wide temperature range and strong vibration resistance.

Working Principle

1. Speed measurement principle

When the speed gear rotates, the sensor will provide a frequency fHz= n×m/60 (n is the rotating speed, p is the gear teeth) of the square wave signal, It can be used for the locomotive electronic control system to do sampling detection of locomotive speed and diesel engine speed.

The inductor need to be a magnetizer, can be groove, raised screw or toothed gear.

There are several parameters as follow for using the sensor to do detection:

m -numbers of the inductors on the measured rotating magnetizer.

n -speed

f -input signal frequency

s-the set meter factor (depends on characteristics of the speed measuring instruments, some speed measuring instruments set gear teeth directly, please follow the manual of the speed measuring instrument you selected to set meter factor)

S=60/M  n = s ´ f = 60 ´ f / m

After setting the induction numbers of measurement system, the setting coefficient of the instrument can be made sure. According to the sensors in each channel that corresponding induction numbers to determine the coefficient of each channel.

For example, as to the speed measurement of a rotation axis, there are 30 gear teeth on the axis, it means the teeth numbers of induction Z = 30, then the output frequency of each channel f = (30/60)´n, rotating speed n = 2f, that means the measured frequency multiply 2 is equal to actual speed. Set the coefficient of speed measuring instrument in 2, means s = 2, then the actual speed of rotor can be displayed directly. Similarly, if every rotor produce 2 signals, then set the coefficient s = 30. Others can be deduced by analogy.

2. CW/CCW discrimination measuring principle

Hall Dual-Channel sensor can discriminate CW run and CCW run easily.

According to the application example in specification 4 to install it, when it runs CW as figure 4, the output wave of channel 1 is ahead of channel 2 90°. Waveform diagram is as follow: When the direction of rotation is opposite to figure 4, the waveform of channel 2 is ahead of channel 1 90°. Waveform diagram is as follow: From the above chart, we can do phase discrimination for the waveforms of channel 1 and channel 2, then to do reverse discrimination.

Dimensions and installation diagram

The follow diagram is the dimensions and installation diagram for Hall Dual-Channel Sensor.

Rz is the radius of gear, X is the distance from addendum to the surface of sensor (0.3≤X≤1.5). One tachometer wheel with 60 gear teeth, mode number is 2, if the sensor is installed as figure 4,channel 1 is ahead of channel 2 and the phase difference is about 90 °. If the mode number is not 2, push the sensor to some angle r when installing the sensor, you can also get the phase difference as about 90 °, shown as figure 5.

For more details, please call us, there are professionals will offer you to the professional solution for your specific conditions. Installation, Usage and Fault handling

1. About SJ series Hall Dual-Channel Sensor, it is not allowed the working power supply connect with locomotive battery, it should connect with isolated power supply to output

2. The sensor output wire must be connected with no mistake according to the specification, make sure there is no short circuit and open circuit appears. Strictly prohibit pulse output and power supply to be short circuit.

3. Install the sensor according to the instructions in the installation diagram. After adjust the gap between the gear and head of sensor to 0.6mm, tighten it.

4. Before the sensor installed into the shell of measured machine, use a ferromagnetic contacts and leaves the sensor, if the output current changes, it is normal.

5. In normal condition, if the output current no changes, the sensor is damaged.

6. If the wire is damaged by external force, the solution is to change a sensor.

(The parameters of phase difference are the data when the speed gear modulus is 2, in line with DIN867 standard.)

1. Installation

The measured machine need to be a magnetizer with raised parts or concave slots.

Suggestion: modulus ≥1.7, the material need to be magnetic low-carbon steel.

P.S.: If the width of the raised part or concave slots is different from the width of the flat surface, the

waveform width will be affected.

nstallation gap: 0.3-1 .5 mm, typical value is 1.0mm.

P.S.: Depends on the vibration of measured machine.

2. Output Characteristics

Frequency response : 0 ~ 20 kHz

Output channels: Double channel

Output waveform: square wave, rise and fall by time 12 u s + 40%

Output amplitude:

high level: U b-(1.8 V + 40%); low level: < 2.2 V

Pulse duty cycle: 50±25

Phase difference: 90±30°

P.S.: Depends on the Installation and the rotation direction of rotating parts. This parameter is suitable for    the installation on the figure 4 of the manual.

Output impedance: 47Ω

3. Work environment requirements

Working power supply: U b＝15VDC±30% （8V～28V）

Current consumption: ≤35mA

Vibration resistance performance: vibration (10Hz ~ 2KHz) 30g, shock 100g

LeakproofnessIP68

4. Electrical characteristics

Power source polarity protection: yes

Output short circuit protection: yes

nsulating strength: 1000V 50Hz1min ( channel and shell)

5. External cable and connection

The wire attached: 6 × 0.5mm2 shielded cable, standard length is 1.0 meter (can be extended according to user’s requirements) 