JPS5915465Y2 - rotary transformer - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a flat rotary transformer used in a two-head video tape recorder and the like.

In the two-head video tape recorder (VTR), which currently dominates home video production, signals induced in the first and second channel heads are transmitted to the subsequent multiplication unit (AMP) through a rotary transformer. It has a circuit configuration.

At this time, the characteristics required of the rotary transformer are:
Since the characteristics of the first channel and the second channel are the same, they are given by the inductance L of each channel and the coupling coefficient k (k is the degree of magnetic coupling between the two windings).

If the above characteristics are not the same, there will be a difference in the amplitude (size and amplitude) of the video signal transmitted to the AMP in the subsequent circuit Q through the rotary transformer. Adjustments will be required.

As a structure for making the inductance L the same, there is a structure proposed earlier (Japanese Utility Model Publication No. 50-14100).

Here, the area S1. between the winding groove and the inner edge of the core in the fixed core and the rotating core is S1. When S2 and S3 are 1/S, +1/52=1/S2+1/S3, the excitation inductances of both winding pairs are equal.

In other words, when 51=S3, the same inductance is obtained.

However, in reality, since the leakage inductance is different for each channel, the substantially same inductance is S,=
The problem cannot be resolved by setting it to 83.

Furthermore, even if almost the same inductance is obtained as described above, the coupling coefficients will not be the same for each channel, so amplitude adjustment in the AMP cannot be avoided.

This invention was made based on the above circumstances, and attempts to solve these problems by changing the groove depth of each channel, thereby providing a rotary transformer that can be used without adjustment.

This invention will be explained in detail below based on the illustrated embodiments.

In the figure, reference numeral 1 denotes a stator, and coil windings 4 and 5 are disposed in annular grooves 2 and 3 arranged concentrically.

Further, on the opposite side thereof, annular grooves 7 and 8 are similarly arranged in the rotor 6 at the portion facing the stator 1,
Coil windings 9 and 10 are arranged in the annular grooves 7 and 8.

Here, coil windings 4 and 9 are for the first channel head, and coil windings 5 and 10 are for the second channel head.

Here, the annular grooves 2 and 7 are deeper than the other annular grooves 3 and 8.

With this configuration, since the coupling coefficient k can be adjusted by changing the depth of the annular groove, -k can be made distantly related.

Then, for example, in order to obtain approximately the same result, we use the previous technology, 1/S, +1/52 = 1/S2 + 1/S3,'',5
If the relationship 1=S3 is utilized in the configuration of this rotary transformer, the equation -k can be substantially related, and the circuit can be made distantly related without adjustment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of this invention, and FIG. 2 is a plan view showing regions S1 to S3. 1... Stator, 2, 3... Annular groove,
4, 5... Coil winding, 6... Rotor, 7, 8... Annular groove, 9, 10... Coil winding.

Claims (1)

[Scope of utility model registration request] In a flat plate rotary transformer in which the inductances of multiple coil windings are the same, the degree of magnetic coupling between each inductance element in the coil windings provided in the multiple annular grooves and between those coil windings is evaluated. A rotary transformer characterized in that the depth of each annular groove is changed so that the coupling coefficient is the same, and the amplitude is made more uniform.