JPH0240562Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a rotary transformer device for connecting a rotary head and an external circuit in a magnetic recording/reproducing device.

(b) Prior Art FIG. 1 is a block diagram showing a conventional erasing rotary transformer.

Referring to FIG. 1, the drawing numbers are as follows: 1 is an oscillation circuit for erasing signals, 2 is an erasure amplifier, 3 is a rotary erasing transformer, and 4 is a rotating erasing head.

Among magnetic recording and reproducing apparatuses, models having functions such as editing and recording generally require a rotary erasing head 4, and accordingly, a rotary erasing transformer 3 as well. Then, as shown in FIG. 1, the erasure signal from the oscillation circuit 1 is amplified by the erasure amplifier 2,
Rotating transformer 3 for erasing the amplified erasure signal
It was supplied to the rotary erasing head 4 via the rotary erase head 4.

However, in addition to a rotary transformer (not shown) for supplying signals to a rotary magnetic head (not shown), an erasing rotary transformer 3 is required, which has the disadvantage of complicating the configuration.

(c) Purpose of the invention The present invention eliminates the above-mentioned drawbacks, and includes a pair of windings provided at opposing positions between the fixed core part and the rotating core part of a rotating transformer. By providing a tap and connecting it to the oscillation circuit, the winding of the fixed side core can also be used as an oscillation coil for erasing, eliminating the need for an independent rotary transformer for erasing.
The aim is to improve efficiency.

(d) Structure of the invention The present invention provides a rotating transformer device used in a magnetic recording and reproducing device, in which a fixed core part and a rotating core part are opposed to each other, and a rotating magnetic field is provided at opposing positions of the fixed core part and the rotating core part. A plurality of pairs of windings corresponding to the number of heads are provided, a pair of windings is provided at opposing positions between the plurality of pairs of windings, and the plurality of pairs of windings are connected to the rotating magnetic head. Then, the pair of windings are connected to a rotary erasing head, an intermediate tap is drawn out from the winding of the fixed core part of the pair of windings, and the intermediate tap is connected to an oscillation circuit for generating an erasure signal. The rotating transformer device uses the winding of the stationary core portion as an oscillation coil for erasing.

(E) Embodiments The details of the present invention will be specifically explained by referring to illustrated embodiments.

FIG. 2 is a circuit diagram showing the rotary transformer device of the present invention.

To explain the figure numbers in FIG. 2, 5 is a rotating transformer device, 6 is a fixed side core part, 7 is a rotating side core part, 8a, 8b are rotating magnetic heads, 9 is a rotating erasing head, 10 is a frequency modulator, 11a, 11b are recording amplifiers, 12a, 12b, 13a, 13b,
14a, 14b are windings, 15 is an intermediate tap, 1
6, 17, 18, 19, 20 are resistances, 21, 2
2 and 23 are capacitors, 24 and 25 are transistors, 26 is a switch, 27 is a power input terminal, 28
2 is an oscillation circuit for erasing signals, and 29 is a voltage dividing circuit.

Referring to FIG. 2, in a magnetic recording and reproducing apparatus that uses two rotating magnetic heads 8a and 8b and has functions such as editing and recording, a rotating erasing head 9 is required. Then, recording is performed using the rotating erasing head 9. The windings 12a, 13a, and 14a are provided in the stationary core part, and the windings 12b, 13b, and 14b are provided in the rotating core part.

First, the recording signal is input to the frequency modulator 10, and the output frequency modulated by the frequency modulator 10 is
The signals are amplified by recording amplifiers 11a and 11b and applied to rotating magnetic heads 8a and 8b via windings 12a and 12b and 14a and 14b, respectively.

Also, voltage V _CC is applied to power input terminal 27, and switch 26 is turned on since it is during recording. Here, the voltage V _CC is divided by the resistors 16 and 17 of the voltage dividing circuit 29, and the current due to the divided voltage is shunted from the point A and input to the bases of the transistors 24 and 25 through the resistors 18 and 19, respectively. be done.
The voltage divided here is the transistor 24, 25
The voltage is sufficient to cause conduction. The capacitor 21 is a decoupling capacitor, which stabilizes the power supply line, so that the current from point B due to the voltage V _CC flows upward from the middle of the winding 13a through the intermediate tap 15, and the alternating current flows through the transistor 24 at point C. The current is input to the collector of the voltage V CC , which turns on the transistor 24 , and at the same time, the current due to the voltage V _CC flows downward from the middle of the winding 13 a through the intermediate tap 15 , and the AC component is input to the collector of the transistor 25 at point D. Transistor 25 becomes conductive. Also, the AC component at point C is fed back to the base of transistor 25 via capacitor 22, and D
The alternating current component at the point is fed back to the base of the transistor 24 via the capacitor 23. Here, the capacitors 22 and 23 are capacitors for determining the oscillation frequency, and the time constant of oscillation is determined by the resistors 18 and 19 and the capacitors 22 and 23. The resistor 20 is a feedback resistor, the transistors 24 and 25 are in a conductive state, and the bases of the transistors 25 and 24 are connected to the bases of the transistors 25 and 24, where AC components from points C and D are returned via capacitors 22 and 23, respectively. Therefore, the potential at point E becomes higher,
Negative feedback is provided by the resistor 20.

This causes the oscillation circuit 28 to oscillate, generating an induced voltage in the winding 13b, which applies an erasing signal to the rotating erasing head 9.

During playback, the rotary erasing head 9 is no longer necessary.
With the switch 26 in the OFF state, the rotating magnetic head 8 is turned off.
It is sufficient to perform reproduction using only a and 8b.

(f) Effects of the invention According to the rotating transformer device of the present invention, an intermediate tap is attached to the winding of the fixed side core of a pair of windings provided at opposing positions between the fixed side core and the rotating side core of the rotating transformer. Since the winding of the fixed side core can also be used as an oscillation coil for erasing by connecting it to the oscillation circuit, there is no need for a separate rotating transformer for erasing, making it possible to improve efficiency and improve productivity and reliability. This provides advantages such as improved performance and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional erasing rotary transformer, and FIG. 2 is a circuit diagram showing a rotary transformer device of the present invention. Explanation of main drawing numbers 5 ...Rotating transformer device, 6...
...Fixed side core part, 7...Rotating side core part, 8a, 8
b... Rotating magnetic head, 9... Rotating erase head,
12a, 12b, 13a, 13b, 14a, 14
b... Winding wire, 15... Intermediate tap, 28 ... Oscillation circuit.

Claims (1)

[Scope of utility model registration request] In a rotary transformer device used in a magnetic recording/reproducing device, a fixed side core portion and a rotating side core portion are opposed to each other, and a plurality of pairs corresponding to the number of rotating magnetic heads are provided at opposing positions of the fixed side core portion and the rotating side core portion. windings are provided, a pair of windings are provided at opposing positions between the plurality of pairs of windings, the plurality of pairs of windings are connected to the rotating magnetic head, and the pair of windings are rotated. An intermediate tap is connected to the erasing head, an intermediate tap is drawn out from the winding of the fixed side core part in the pair of windings, and the intermediate tap is connected to an oscillation circuit for generating an erase signal to erase the winding of the fixed side core part. A rotating transformer device characterized by using a wire as an oscillation coil for erasing.