JPS5923233Y2 - tape recorder - Google Patents

Description

[Detailed description of the invention] The present invention relates to a tape recorder that uses electromagnetic plungers to switch operating states. The purpose is to ensure reliable switching.

In conventional tape recorders of this type, if it is a cassette type, a first electromagnetic plunger is used to advance the head board and press the pinch roller against the capstan, and a second electromagnetic plunger is used to switch the recording/playback selector switch to the recording side. An electromagnetic plunger is provided, and the first and second plungers are kept inactive in the stopped state, and the first plunger is operated by operating the regeneration button to enter the regeneration operation state, and the regeneration button and the regeneration button are operated. By simultaneously operating the recording button, the first and second plungers were operated simultaneously to enter the recording operation state.

According to such a configuration, since two plungers must be operated simultaneously when recording, it is necessary to set the voltage (current) capacity of the power supply circuit to a high value, and if this is neglected, This resulted in the problem that the recording operation could not be performed.

In other words, in general, when an electromagnetic plunger is started, it will not operate unless a current several times higher than the voltage (current) value in the operation holding state is passed, so if you try to operate multiple electromagnetic plungers of this nature at the same time, When starting up, it is necessary to apply a considerable amount of voltage (current).

Therefore, in conventional tape recorders, it is necessary to make the capacity of the power supply circuit larger than necessary, which increases the cost, and when using a battery as a power source, the plunger stops working due to voltage drop. Recording operations may become impossible.

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

In the figure, 1 is a power switch, and when this switch 1 is closed, a power circuit (not shown) is connected to a first power line 2, a second power line
A voltage vH5 is supplied between the power supply line 3 and the ground line 4, respectively.

The voltage VH is high enough to activate the electromagnetic plunger, and the voltage vL is low enough to keep the activated plunger in operation, with the relationship VH>VL.

The first power line 3 is connected from a resistor 5 to a drive circuit 8 for a first plunger 7 via a normally open play switch 6, and from a resistor 9 to a normally closed record switch 10. It is connected to the drive circuit 12 of the second plunger 11 via.

The regeneration switch 6 is closed by pressing a regeneration button (not shown), and is maintained in the open state by locking the regeneration button in the pressed position.

The recording switch 10 is opened by pressing a recording button (not shown), and is maintained in the open state by locking the recording button in the pressed position.

Further, the plunger drive circuits 8 and 12 have the same configuration, and the same constituent parts are given the same numbers, and only one of the drive circuits 8 will be explained, and the other will be omitted.

This drive circuit 8 can be roughly divided into transistors Q1.
Q2, a high voltage supply circuit consisting of a capacitor C1 forming a time limit circuit, a resistor R1, bias resistors R2 and R3, and a transistor Q3. Q4 and bias resistor R4~
It is divided into two circuits: a low voltage supply circuit consisting of R6 and a backflow prevention diode D1.

Regarding its operation, when the regeneration button is operated with the power switch 1 closed and the regeneration switch 6 is closed, the transistor Q1. Q3 is off, transistor Q2. Q4 is turned on, voltage 1 (=vL+VH) is applied to the first plunger 7 as shown in FIG. 2, and the plunger 7 is actuated.

When a certain time t (t2t1) determined by the time constant of capacitor C1 and resistor R1 has elapsed, transistor Q1
is turned on, transistor Q2 is turned off, and the plunger 7 has a voltage v1 (=Vt
) is applied to prevent unnecessary power consumption.

It goes without saying that when the regeneration switch 6 is opened, the plunger 7 returns to its non-operating state.

The other drive circuit 12 operates in a similar manner, but since this drive circuit 12 is controlled by the normally closed recording switch 10, when the power switch 1 is closed and the recording button is not operated, the second plan is activated. The plunger 11 is in an activated state, and when the recording button is operated, the plunger 11 is returned to its inactive state.

The first plunger 7 moves the head substrate 13 forward against the force of a return spring (not shown), brings the head 14 and 15 mounted thereon into contact with the magnetic tape 16, and also moves the pinch roller 17 against the tape. The tape is brought into pressure contact with the capstan 18 via the tape 16 to run the tape at a constant speed.

Further, when the second plunger 11 is operated, the recording/reproduction changeover switch 19 is shorted to the reproduction side, that is, the common contact C and the reproduction contact P are short-circuited, thereby making the reproduction circuit operable.

In this recording/playback selector switch 19, when the second plunger 11 is not activated, the movable piece is returned by the force of the spring, and the recording side, that is, the common contact C and the recording contact R are short-circuited, and the recording circuit is enabled to operate. be.

Next, the operation of the above embodiment will be explained. First, in a stopped state where the power switch 1 is simply closed, only the second plunger 11 operates and its operating state is maintained.
The regeneration circuit is now operational.

When the playback button is pressed in this state, the first plunger 7 is operated and maintained in its operating state, and the tape is run at a constant speed to perform a playback operation.

Next, when you press the play button and the record button at the same time in the above stopped state, the second
The operation of the first plunger 11 is released, and the first plunger 7 is activated to perform a recording operation.

Since the tape recorder of this embodiment has such a configuration and operation, only one plunger is operated even during recording, the capacity of the power supply circuit is small, and the plunger can be operated reliably even when the voltage is reduced. It can be made to work.

As explained above, according to the tape recorder of the present invention,
It is possible to reliably switch the operation using an electromagnetic plunger even in a power supply circuit with a small capacity, and it eliminates the trouble of having to use a large power transformer to stabilize the power supply voltage as in the past. Therefore, it is possible to provide a tape recorder that is advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a tape recorder according to an embodiment of the present invention, and FIG. 2 is an operating voltage characteristic diagram of a plunger of the same tape recorder. 1...Power switch, 6...Reproduction switch, 7...First plunger, 10...
...Recording switch, 11...Second plunger, 17...Pinch roller, 19...
- Recording/playback selector switch.

Claims (1)

[Scope of utility model registration request] The recording/playback switch, which is normally set to the recording side, and the first switch, which switches the recording/playback switch to the playback side.
and a second electromagnetic plunger that moves at least the pinch roller to press the capstan, and a first circuit that operates the first electromagnetic plunger and maintains its operating state when the power is turned on. , a second circuit that activates the second electromagnetic plunger and maintains its operating state when a playback button is operated, and a third circuit that releases the first circuit when a record button is operated, and the power is turned on. Sometimes, only the first electromagnetic plunger is activated, and during playback, the first electromagnetic plunger is activated and the second electromagnetic plunger is also activated, and during recording, the first electromagnetic plunger is deactivated. A tape recorder configured to be activated so that only the second electromagnetic plunger is activated.