mr sensor series section

The Other Use, Potential Meter
Because common potential meter has contacting point to contact mechanically, the potential meter using MR-SENSOR which has discontinuous resistance against frictional wear and dust can change resistance properly according to change of magnetic field and there isn't any contacting point.
Essentially, MR-SENSOR is useful for controllable changing resistance which needs continuous change.

If we find the difference between the tow signals, we will be able to know whether the revolving wheel of a clockwork is turning to the right or to the left.
This encoder is usefully used to control revolution of the motor precisely.
Therefore, for the main sub-motor of a precise machines for engineering works, MR-SENSOR is used which has fast speed response and is strong for contamination of oil, etc.

Then we will have the signal at two output terminal such as the following picture. We will be able to see two signal, Va and Vb which have a little difference.
Cycle of this signal at normal wavelength corresponds to one clockwork of the revolving wheel of a clockwork.
Therefore, if we divide the number of peak obtained by the number of clockwork,
we will get the number of revolution And the little difference between Va and Vb shows the revolving direction

The following MR-SENSOR is an encoder used to detect revolution and location. This uses bridge contacted four MR devices arranged at a certain distance.
It is to draw this MR-SENSOR near to revolving wheel of a clockwork.

Magnetic Encoder

However, because it is very difficult to read the magnetic printing pattern, we have presented an example which can be easily read.

At machines such as vending machines which receive notes, MR-SENSOR can be used to judge authenticity of a note by this signal.

Following picture is what we have seen a paper money by MR-SENSOR.
We have used the US 1$ note. Because we can't show all of the magnetic pattern, we have connected an actual picture (left) and an magnetic pattern (right) diagonally.
As the printed shape, we can see that signal is detected.

Magnetic Pattern of Paper Money

Although there is very little change in magnet, MR-SENSOR can certainly detect the pattern.
Following is the circuit diagram we have used. However, because it is very difficult to read the magnetic printing pattern, we have presented an example which can be easily read.

Of course, if we pass the E12B type letters which are magnetically printed by this standard through the detecting surface of the MR-SENSOR, MRS Output Terminal will have the signal shown in the following picture.

Then, how does MR-SENSOR detect the pattern through reaction with magnetic printing? Followings are examples of letters made for the use of information technology.
These letters are prescribed at JIS X9002. (E13B type). JIS X9002 is a standard for the letter types for reading the letters printed in magnetic ink and essential spec..

Magnetic printing menas to print in ink mixed with magnetic powder and good examples of things using magnetic printing are paper money of various countries.
However, magnetic material included in magnetic printing is very little, so a thousand-won note doesn't stick fast to magnet and we don't know this fact in our daily lives.

The most important use of MR-SENSOR is to read magnetic printing pattern.