KR840002884Y1 - Power source cut off circuit - Google Patents

Abstract

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Description

Power cutoff device at tape completion and no signal

1 is a circuit diagram of the present invention.

2 is another exemplary embodiment applied only when the tape is finished running in the present invention.

* Explanation of symbols for main parts of the drawings

A: Signal amplification unit B: Stop detector

C: waveform shaping part D: switching circuit part

1: power socket 2: bridge rectifier circuit

3: Auto stop circuit 4: Rotation detection device

5: Audio signal input terminal Q ₁ -Q ₆ : Transistor

D ₁ -D ₄ : Diode M: Drive Motor

The present invention is in tape cassette when the tape is finished or long time audio signal (in the absence of AM or FM broadcast signal, the power supply is automatically cut off to eliminate unnecessary power consumption and noise when the tape is finished and no signal status) To the power off chapter in.

Conventionally, when the tape driving is completed while the cassette radio is in use and the system stops automatically or there is no broadcasting signal for a long time, the power is continuously supplied when the user does not turn off the power switch. Occurrence has caused problems such as degrading the performance of the device.

In consideration of these problems, the present invention installs a relay contact switch in parallel with the power switch, and uses a switching circuit composed of transistors and diodes, even when the tape is finished running or when the power switch is not "off" in a broadcast-free signal state. It can be automatically cut off the power, described in detail by the accompanying drawings as follows. FIG. 1 is an implementation circuit diagram of the present invention, in which a normal bridge rectifier circuit 2 and a capacitor C ₁ are connected to the secondary side of a power transformer T, and the output terminal connection point A and the slip switch SW _{3 are} connected to each other. A stop detector (b) consisting of a resistor (R ₁ ), a transistor (Q ₁ ), a diode (D ₂ ), and an auto stop circuit (3) is connected between one end (B). In addition, a signal amplifying part (A) consisting of resistors R ₂ -R ₅ , capacitor C ₂ , and transistor Q _{2 is} connected to the audio signal input terminal ₅ , and a capacitor C ₃ − is connected to the output terminal thereof. C ₅ ), a diode (D ₁ ), and the waveform shaping section (C) consisting of the resistors (R ₇ ), (R ₈ ) are connected, and the transistor (Q ₃ ), (Q _4), the resistance (R ₉ -R ₁₁₎ and a diode (d ₃₎ connected to the switching circuit section (d) to connect to one end (B) of the sleep switch (SW ₃₎ and, a sleep switch (SW ₃₎ At the other end of the transistor Q ₅ , Q ₆ is connected via a resistor R ₁₂ , and the relay RY ₁ is connected to the emitter side of the transistor Q ₆ , by the relay RY ₁ . The auxiliary switch SW ₄ controlled on and off is connected in parallel to the main power switch SW ₁ .

Unmarked AC is AC input power, 1 is power socket, SW ₂ is input power selector switch, F ₁ , F ₂ is fuse, B ⁺ is DC power, R ₁₃ is resistor, D ₄ is reverse surge voltage Each absorption diode is indicated. Referring to the effect of the present invention configured as described above are as follows.

In FIG. 1, when the main power switch SW ₁ is turned "on", a constant DC voltage is supplied to each circuit portion through the bridge rectifying circuit 2 and the capacitor C ₁ . Assuming that when the tape during running in such state amplifies rectifying the voltage induced in the rotation detecting element (4) of the automatic stop circuit 3, the output terminal has a low level (Low Level), the signal is displayed transistor (Q ₁₎ of Although applied to the base, the transistor Q ₁ is in the " off " state, which causes a high level signal to appear on the collector side thereof, so that this signal is connected to one side of the sleep switch SW ₃ through the diode D ₂ . In this case, when the sleep switch SW ₃ having the sleep timer function is turned "on" as needed just before going to bed, the high level signal is transmitted through the resistor R ₁₂ . (since Q ₆₎ to thereby "on", the relay (the RY ₁ woman connected to the emitter teocheuk of the transistor (Q ₆₎ auxiliary switch (SW ₄₎ Q ₅₎ (relay (if RY ₁₎ woman "on" and A switch that is "off" if not a woman ) Is the "on" state.

In this way, even if the main power switch (SW ₁ ) is set to the "off" state while the tape is running, the auxiliary switch (SW ₄ ) remains in the "on" state. do.

If the tape continues driving and the driving state is completed as described above, at this time, the high level signal is displayed at the output terminal of the automatic stop circuit 3, and the transistor Q ₁ is turned on. therefore appear that side his collector low level signal, the signal diagram dE (D ₂₎ to be "oN" mothayeo not conductive slip switch (SW _3), even if the transistor (Q ₅₎ (Q ₆₎ is "off" state, the Therefore, since the relay RY ₁ connected to the emitter side of the transistor Q ₆ cannot be excited, the main power switch SW ₁ and the auxiliary switch ( ₄ ) that have been turned off by turning the auxiliary switch SW ₄ into the "off" state. SW ₄ ) are all turned off, so the power is automatically cut off.

On the other hand, when an audio signal is input to the audio signal input terminal 5, this signal is amplified by the signal amplifying section a, and the amplified signal is smoothed by the waveform shaping section c. Since the signal conducts the transistor Q ₃ of the switching circuit portion D through the resistor R ₉ , it appears as a low signal on the collector side thereof and is applied to the base side of the transistor Q ₄ , so that a high level signal is applied to the collector side thereof. This signal is displayed at one end of the slip switch SW ₃ through the diode D ₃ , and as described above, the high level signal is generated because the sleep switch SW ₃ is set to the "on" state. Since transistor Q ₅ (Q ₆ ) is "on" through resistor R ₁₂ , relay RY ₁ connected to the emitter side of transistor Q ₆ is excited and auxiliary switch SW ₄ is "on". "State. Thus, even if the main power switch SW ₁ is set to the "off" state while the signal is being input to the audio signal input terminal 5, the auxiliary switch SW ₄ remains in the "on" state. The power supply will continue, allowing the audio signal to continue to be heard.

If the audio signal is continuously input to the input terminal 5 and no audio signal is input as described above, there is no signal appearing at the output terminals of the signal amplifying unit (a) and the waveform shaping unit (c). Since the signal negatively conducts the transistor Q _{3 in the} switching circuit section D through the resistor R ₉ , it appears as a high level signal on the collector side thereof and is applied to the base side of the transistor Q ₄ . This signal is represented as a low level signal, and this signal does not conduct the diode D ₃ so that the transistor Q ₅ and Q ₆ are turned "off" even when the sleep switch SW ₃ is turned on. Likewise, the relay RY ₁ is not excited, and the auxiliary switch SW ₄ is turned off, and the power is automatically shut off.

In this way, even when the tape running state or the audio signal (broadcast signal) is output, the sleep switch SW ₃ is turned "on" immediately before going to bed, and the main power switch SW ₁ is set to "off" state. an auxiliary switch (SW ₄₎ because it remains in the "on" state, the receiver is automatically the auxiliary switch (SW ₄₎ value is "off" when the status doedaga power is still not the tape running completed or when the audio signal is output It can cut off the power supply. FIG. 2 is another exemplary view of the present invention which is applied only when the tape is completed except for the no-signal state of the present invention. FIG. 1 shows the function of selecting the stop detection unit (b) except the stop function (FF, REW, Play, REC). When the operation state is explained by directly connecting the switch (SW ₅ ) which is turned on in the auto-stop state when the driving is completed and the DC driving motor (M) grounded at one side, the operation state is described. SW ₅ ) is in the "on" state to drive the DC drive motor (M), and the transistor (Q ₅ ) (Q ₆ ) to the "on" state through the resistor (R ₁₂ ) and capacitor (C ₁₀₁ ). Therefore, the relay RY ₁ connected to the emitter side of the transistor Q ₆ is excited so that the auxiliary switch SW ₄ is in the "on" state, and then the power supply is continued even when the main power switch SW ₁ is "off". Is maintained so that the tape running state is maintained. Since W ₅ ) is "off" and transistors Q ₅ and Q ₆ are also in a non-conductive state, therefore, the switch SW ₄ is in the "off" state, and as described above, the power supply is automatically cut off when the tape is completed. I can make it.

The present invention, which operates as described above, provides a relay contact in parallel with the power switch when the tape is finished running or when there is no audio signal for a long time, and before the user goes to bed by using a switching circuit composed of a transistor and a diode. After the sleep switch is turned on, the main power switch is set to the off state, and the power is automatically cut off by the auxiliary switch by the relay drive even when sleeping.This prevents unnecessary power loss and other noises. It is effective to extend the life of the device.

Claims (1)

In the cassette radio, the auxiliary switch SW ₄ is connected in parallel to the main power switch SW ₁ , and the transistors Q ₂ , the resistors R _{2 to} R ₆ , and the capacitor C _{2 are} connected to the audio signal input terminal 5. Connect a signal amplification unit (A) and connect the waveform shaping unit (C) with a capacitor (C ₃ -C ₅ ), a diode (D ₁ ), and a resistor (R ₇ -R ₈ ) to its output terminal. Through this, the transistors Q ₃ -Q ₄ and the switching circuit part D consisting of the resistors R ₁₀ -R ₁₁ are connected, and the output end of the switching circuit part D and the output end of the normal stop detection part B are connected to each other. Are connected to one side B of the slip switch SW ₃ , and the relay RY ₁ is driven between the other side of the switch SW ₃ and the relay RY ₁ controlling the auxiliary switch SW ₄ . And a transistor (Q ₅ ) (Q ₆ ) connected to each other, characterized in that the power supply cut-off device at the completion of the tape run and in the no signal state.