JPS5935865Y2 - tape recorder - Google Patents

Description

[Detailed description of the invention] The present invention relates to a tape recorder equipped with two external input terminals, such as a line input terminal and a microphone terminal. It is about trying to do things efficiently.

Conventional tape recorders that have two external input terminals, a line input terminal and a microphone terminal, require a changeover switch to manually switch between the line signal and microphone signal from the outside, and a main variable resistor to adjust the level of the line signal. A sub-variable resistor is provided to adjust the level of only the microphone signal.Use the selector switch above to select the signal to be recorded and adjust either the main or sub-variable resistor to record. was.

However, this type of configuration has the problems of not only increasing the number of parts but also tending to be complicated to operate.

The present invention is intended to eliminate such conventional drawbacks, and one embodiment thereof will be described below with reference to the drawings.

In FIG. 1, 1 is a line input jack to which a high-level line signal is supplied, 2 is a microphone jack to which a low-level microphone signal is supplied, 3 and 4 are recording amplifiers, and 5 are these two amplifiers 3 and 4. A variable resistor 6 for adjusting the recording level is interposed between the recording heads.

The microphone jack 2 has terminals 23 to 2f, terminals 2a and 2b are normally closed switches, terminals 2c,
2d constitutes a normally closed type switch, and terminals 2d and 2e constitute a normally open type switch.

Terminal 2f is a ground terminal, and a resistor 7 is connected between this terminal 2f and the above-mentioned terminal 2e.

The line jack 1 is connected to a variable resistor 5 via terminals 2d and 2c.

In the above embodiment, when a plug is connected to the line input jack 1 and a line signal (high level signal) is supplied, the level of this signal is adjusted by the variable resistor 5, and the amplifier 4
, is recorded on the magnetic tape via the head 6.

On the other hand, when the microphone plug 8 is connected to the microphone jack 2 as shown in FIG. 2, the terminals 2a+2b are opened.
Terminals 2c and 2d are open, terminal 2d.

2e is short-circuited, and a microphone signal (low level signal) is sent to the amplifier 3 via the terminal 2a.

The amplified signal here is level-adjusted by a variable resistor 5, and then sent to an amplifier 4 and a head 6, similar to the above-mentioned line signal.
recorded on tape via

At this time, the line signal is not sent to the recording circuit system because the terminals 2d and 2c are opened, and the line signal is shunted by the resistor 7.

As described above, according to the present invention, when a microphone plug is inserted into the microphone input terminal, the input of the recording circuit is automatically switched from line input to microphone input.
Furthermore, the recording level of any human input signal can be adjusted using a single variable resistor, greatly improving operability.

Furthermore, the line input was grounded when the microphone plug was inserted, and the input end of the first amplifier was grounded when the microphone plug was removed.
In particular, the level of noise mixed into the recording signal can be extremely reduced, which has a great effect on improving the recording quality.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams showing one embodiment of the present invention. 1...Line input jack, 2...Microphone jack, 5...Variable resistor for adjusting recording level, 6...Recording head.

Claims (1)

[Scope of utility model registration request] It comprises a line input terminal, a microphone input terminal, and a recording circuit, and the recording circuit is configured by a cascade connection of a first amplifier, a variable resistor for recording level adjustment, and a second amplifier, and a microphone plug is connected to the microphone input terminal. A first and a second switch are provided which are switched in conjunction with each other by inserting the microphone plug, and when the microphone plug is not inserted, the first switch is closed or the input terminal of the first amplifier is grounded via the microphone input line. At the same time, the second
the first contact of the switch is closed or the input line of the line input terminal is connected to the input side of the variable resistor for adjusting the recording level;
On the other hand, when a microphone plug is inserted, the first switch is opened to input the microphone signal to the first amplifier, and the first contact of the second switch is opened and the second contact is closed, or the input line of the line input terminal is connected. A tape recorder characterized in that the tape recorder is configured to be grounded through its second contact.