JPS605492Y2 - plunger drive circuit - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plunger drive circuit that reliably switches a slide switch.

A magnetic recording/reproducing device is usually provided with a slide switch for mechanically switching between a recording mode and a reproduction mode, and the switch is mechanically linked to the operation of a record button and/or a reproduction button.

Therefore, the present invention specifically proposes a new plunger drive circuit in order to electrically operate a slide switch as devices become more electronic.

The present invention will be described below with reference to illustrative embodiments.

First, the first embodiment of the switch switching mechanism shown in FIG. .

By selectively applying an excitation current to one of the LPs,
The slide switch 2 is configured to be able to be switched between two positions.

In the second embodiment shown in FIG. 2, a movable piece 1a is engaged with a slide member 2a of a slide switch 2, and one of a pair of disc-shaped magnetic poles 1b and 1c sandwiching the movable piece 1a is excited. In order to do this, current is selectively applied to the excitation coils LR and LP to move the movable piece 1a to two positions, thereby switching the slide switch 1.

That is, the present invention selectively applies excitation current to the pair of excitation coils LR and LP to record and record the slide switch 2.
This is a plunger drive circuit employed in a switch switching mechanism configured to switch between two regeneration positions.

FIG. 3 shows a circuit according to the first embodiment of the present invention, in which when the operation switch S is open, current is passed through the excitation coil LR for recording, and the slide switch 2 is placed in the recording position, and when the operation switch S is closed, the excitation coil LP for reproduction is passed through the slide switch 2 to the recording position. This is a circuit that switches the slide switch 2 to the playback position by passing current through it.

That is, when the operating switch S is in the open state, the first transistor Q1 is in the OFF state, so the second transistor Q2
is in the ON state, a holding current flows through the recording excitation coil LR by the first current limiting resistor R1 connected to the emitter of the second transistor Q2, and the third transistor Q3 connects the emitter to the shorting type changeover switch. It is in an OFF state with a ground fault at SW, and no current flows through the regeneration excitation coil LP.

When the operation switch S is closed in such a state, the first transistor Q1 is turned on and the second transistor Q is turned on.
2 is turned OFF and the holding current of the recording excitation coil LR is cut off, while the third transistor Q3 whose emitter is grounded is turned ON and the reproduction excitation coil L is turned on.
The changeover switch S is operated by passing a large driving current through P to switch and drive the slide switch 2 to the playback position.
W is switched to the reproduction side P, the emitter of the third transistor Q3 is released from the ground fault state, and a holding current is caused to flow through the reproduction excitation coil LP by the second current limiting resistor R2 connected between the emitter and the ground. Hold the slide member 2a on the reproduction side.

Note that the second capacitor C2 connected between the collector of the third transistor Q3 and the ground is in a charging state when the emitter current of the third transistor Q3 flows through the second current limiting resistor R2 and the collector voltage increases. Therefore, a large current is temporarily applied to the reproducing excitation coil LP to completely slide the slide member 2a to the reproducing position, and there is a risk that the sliding of the changeover switch SW will stop the moment it is separated from the recording terminal R. This problem has been resolved.

Next, when the operating switch S is opened, the first transistor Q1 is turned off and the second transistor Q2 is turned on.
With the emitter of the second transistor grounded by the changeover switch SW, a large current is applied to the recording excitation coil LR to drive the slide member 2a toward the recording side, and the first capacitor When C1 is in a charged state, a holding current is passed through the recording excitation coil LR via the first current limiting resistor R1.

Therefore, according to this embodiment, the first and second capacitors C
Since the charging current flowing through I and C2 (delay means) ensures complete sliding of the slide member 2a, there is no risk of malfunction.

FIG. 4 shows a second embodiment of the present invention, in which the operation switch S
This embodiment is the same as the first embodiment except that it is of a switching type rather than an opening/closing type, and the first transistor Q1 is omitted, so the explanation thereof will be omitted with reference to FIG.

According to the present invention described above, when the plunger is actuated by the shorting type changeover switch, both excitation coils are made conductive in a complementary manner, so that the shorting type changeover switch activates both excitation coils, thereby preventing malfunction. The effect is great without having to do anything.

[Brief explanation of drawings]

Fig. 1 shows a first embodiment of the slide switch switching mechanism of the present invention, Fig. 2 shows a second embodiment of the same, Fig. 3 shows a first embodiment of a plunger drive circuit of the present invention, and Fig. 4 represent the circuits of the second embodiment, respectively. Explanation of main drawing numbers, S...operation switch, Q2゜Q3...second and third transistors (switching means), LP, LR...excitation coil, SW
......Changing switch, C1, C2...First and second capacitors (delay means).

Claims (1)

[Scope of Claim for Utility Model Registration] A plunger that displaces a movable piece to two positions by displacing an excitation coil for reproduction and an excitation coil for recording, a slide switch that can be changed to two positions by the movable piece; an exciting coil, a first switching means, and a first
a series circuit comprising a current limiting resistor connected between a power source and ground, the recording excitation coil, a second switching means, and a second switching means;
a series circuit comprising a current limiting resistor connected between the power source and the ground; a first capacitor connected between the connection point between the reproducing excitation coil and the first switching means and the ground; a second capacitor connected between a connection point between the excitation coil and the second switching means and the ground; and a reproduction side terminal connected to a connection point between the first switching means and the first current limiting resistor. and shorting type switching that slides to two positions together with the slide switch by connecting a recording side terminal to a connection point between the second switching means and the second current limiting resistor and connecting a common terminal to ground. A plunger drive circuit comprising: a switch; and a switch control circuit that opens and closes the first and second switching means in a complementary manner when operated.