KR930000332Y1 - Head angle adjusting of stero cassette tape player - Google Patents

Abstract

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Description

Head Azimuth Adjustment Status Indicator of Stereo Cassette Tape Player

1 is a conventional head azimuth adjustment state indicating circuit diagram.

2 is a head azimuth angle fixed state indicating circuit according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Differential Amplifiers Q1 to Q6: Transistors

I1, I2: Channel input terminal LED2 and LED3: Light emitting diode

The present invention relates to a head azimuth adjustment state indicating circuit of a cassette tape player. In particular, a head azimuth (HEAD AZIMUTH) of a cassette generally configured to adjust the head azimuth angle by detecting whether an input signal input is above a set voltage level. The adjustment is made by using an oscilloscope or the like in a production maker. When the head azimuth angle is changed by disassembling or assembling a cassette tape player, it is difficult for the user to adjust it.

Utility Model Registration Application No. 86-18526 has been devised to solve the above-mentioned drawbacks. However, since the light emitting diode is turned off only when the signal input to the left and right channels is in phase, a signal having a voltage level equal to or less than the reference voltage is in phase. Even when entered, the head azimuth adjustment was marked as complete.

Accordingly, the present invention provides a head azimuth adjustment state indicating circuit of a cassette tape player which can detect the presence or absence of the phase voltage and the phase voltage of the signal input to the left and right channels by eliminating the above disadvantages. There is this.

The head azimuth adjustment state indicating circuit of the cassette tape player according to the present invention is connected between the transistor Q3 which is connected from the differential amplifier 1 and turned on or off in accordance with the input signal, and is connected between the transistor Q3 and the supply power supply Vcc. In the head azimuth adjustment state indicating circuit of a stereo cassette tape player composed of LEDs 1 and 3 lit in accordance with an operating state, resistors R10 and R20 connected in series between two input terminals of the differential amplifier 1, and the resistors R10 and R20. The resistor R30 and the semi-fixed resistor SVR1 connected in series between the connection point and the ground, the transistor Q6 which are turned on or off in accordance with the voltage level of the input signal connected from the connection point of the resistor R30 and the semi-high resistor SVR1, and supplied with the transistor Q6. Connected between the power supply Vcc terminals and turned on depending on whether the transistor Q6 is in operation A light emitting diode LED3 and a transistor Q5 that is turned on or off in response to a signal input from the output terminal of the differential amplifier 1, a transistor Q4 that is turned on or off in accordance with a signal input from the transistor Q5, and The light emitting diode LED2 is connected between the transistor Q4 and the supply power supply Vcc terminal and is turned off or off depending on whether the transistor Q4 is operated.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conventional head azimuth adjustment state indicating circuit. When an in-phase signal is inputted to the channel input terminals I1 and I2, transistors Q1 and Q2 of the differential amplifier 1 are simultaneously turned on to operate their emitter currents. If the current at the collector terminal of transistor Q1 is much greater than the base current of transistor Q1, the collector current is equal to the emitter current and is opposite in direction, so the collector voltage of transistor Q1 becomes "0" V. Therefore, since "0" V is supplied to the base terminal of the transistor Q3, it is turned off. Therefore, the light emitting diode LED1 is turned off to recognize that the head azimuth adjustment is completed.

On the other hand, if the phases of the signals input to the channel input terminals I1 and I2 are not the same, for example, if the phase of the signal input to the 12 channel terminal is 90 ° ahead of the signal input to the I1 channel, for example, the transistor first. Since Q2 is ON and transistor Q1 is in the OFF state, the potential of the collector terminal of transistor Q1 is Vcc, and the transistor Q3 is ON. Therefore, the light emitting diode LED1 emits light, and the transistor Q1 is turned on next time. Since the transistor Q2 is in the off state, the voltage dropped from the resistor R4 is supplied to the base terminal of the transistor Q3 so that the light emitting diode LED1 emits light. . That is, the light emitting diode LED1 is in the lit state.

Therefore, FIG. 1 indicates the azimuth adjustment state of the head as the lighting state of the light emitting diode LED1 according to whether or not the input phase is the same, and operates regardless of the voltage level of the input signal. Therefore, the present invention is to provide an azimuth adjustment state indicating circuit of the head capable of detecting the level of the input signal.

2 is a head azimuth adjustment state indicating circuit diagram according to the present invention, in which channel input terminals I1 and I2 are connected to input terminals of differential amplifier 1 via capacitors C1 and C2, respectively. The output terminal of the differential amplifier 1 is connected to the base terminal of the transistor Q5 through which the emitter terminal is grounded through the capacitor C3 and the resistor R40. The collector terminal of the transistor Q5 is connected to the base terminal of the transistor Q4 whose emitter terminal is grounded via the resistor R60, and is connected to the collector terminal of the transistor Q4 via the resistor R50 and the light emitting diode LED2. The connection point of the resistor R50 and the light emitting diode LED2 is connected to the supply power supply Vcc terminal and connected to the collector terminal of the transistor Q6 to which the emitter terminal is grounded via the light emitting diode LED3. On the other hand, the resistors R10 and R20 are connected in series between the channel input terminals I1 and I2, and the connection points thereof are connected to the base terminal of the transistor Q6 via the resistor R30, and the base terminal is configured to be grounded through the semi-fixed resistor SVR1. .

Referring to the operation of the present invention configured as described above are as follows.

(1) When the phases of the signals input to the channel input terminals I1 and I2 are the same, the output of the differential amplifier 3 becomes almost " 0 " V, so that the transistor Q5 is turned off. Therefore, transistor Q4 is turned on so that LED LED2 is turned on.

(2) If the voltage level of the signal input to the channel input terminals I1 and I2 is higher than the set reference voltage level, the input signal is divided by the reference level setting resistors R10, R20 and R30 and the semi-fixed resistor SVR1. do. Therefore, the controller can see that the transistor Q6 is turned on and the light emitting diode LED3 is turned on so that the input level is larger than the set level value.

On the other hand, when the voltage level of the signal passing through the resistors R10 and R20 is lower than the base terminal trigger voltage of the transistor Q6, the transistor Q6 is turned off and the light emitting diode LED3 is turned off.

(3) If the phases of the signals inputted to the channel input terminals I and I are different, the differential amplifier 1 outputs a logical " high " signal to turn on the transistor Q5. Therefore, transistor Q4 is turned off so that LED LED2 is turned off.

That is, the light emitting diodes LED2 and LED3 emit light only when the level of the input signal is in phase and is equal to or higher than the reference voltage level. If the input phase is in phase but lower than the reference voltage level, the LED LED2 is turned ON while the LED3 is turned off.

Therefore, the head azimuth angle adjustment may be performed by mounting a tape recording a square wave signal of 8 KHz on a deck, and then regenerating it to adjust the head azimuth regulators left and right so that the LEDs LED2 and LED3 light up.

As described above, according to the present invention, the head azimuth adjustment state can be indicated according to the phase and voltage level of the input signal, thereby making it possible to accurately and easily adjust the head azimuth angle.

Claims (1)

A differential amplifier (1) connected from two channel input terminals, a transistor (Q3) turned on or off in accordance with a signal input from the differential amplifier (1), and connected between the transistor (Q3) and a supply power supply Vcc. In the head azimuth adjustment state indicating circuit of a stereo cassette tape player composed of LEDs 1 and 3 lit in accordance with the operating state of the resistors, resistors R10 and R20 are respectively connected between two input terminals of the differential amplifier 1, and the resistors R10 and The resistor R30 and the semi-fixed resistor SVR1 are connected between the R20 connection point and the ground, and the transistor Q6 which is turned on or off in accordance with the voltage level of the signal input from the connection point of the resistor R30 and the semi-fixed resistor SVR1 is connected, and the collector of the transistor Q6 is connected. The light emitting diode LED3 is connected between the terminal and the supply power supply Vcc terminal, and is input from the output terminal of the differential amplifier 1. Is connected to a transistor Q5 that is turned on or off in accordance with a signal, and a transistor Q4 that is turned on or off in accordance with a signal input from the transistor Q5 is connected, and the transistor Q4 is connected between the collector terminal of the transistor Q4 and the supply power supply Vcc terminal. The head azimuth angle adjustment state indicating circuit of the stereo cassette tape player, characterized in that the light emitting diode LEDs 2 which are turned off and off are connected according to whether the operation is performed.