KR930007548Y1 - Dc-dc converter - Google Patents

Abstract

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Description

DC-DC Converter Circuit in Headphone Stereo

1 is a conventional DC-DC converter circuit.

2 is a block diagram of a DC-DC converter circuit of the present invention.

3 is a circuit diagram showing an embodiment of FIG.

4 is a diagram comparing the efficiency of the present invention and the conventional DC-DC converter circuit.

* Explanation of symbols for main parts of the drawings

10: input power filter circuit 20: power switching circuit

30: DC-DC coil part 40: delay circuit

50: rectifier circuit 60: voltage detection and switching circuit

70: output power filter circuit

The present invention relates to a DC-DC converter circuit of headphone stereo that can directly boost to an output power of 2.4V without boosting the input power more than 12V.

In general, 1.5V headphone stereo operates a set with one 1.5V battery, but internal circuits do not operate with this 1.5V and operate only when a power supply of 2V or more is applied (for example, a microcomputer, an IC, etc.). ), The 1.5V headphone stereo must use a DC-DC converter circuit to boost the 1.5V input power to 2V or higher.

In the conventional DC-DC converter circuit, as shown in FIG. ₁ , an input power switching unit _{1 including a} transistor Q ₁ and a coil L ₁ for boosting the output of the switching unit 1 to 12V or more. ), A transistor (Q ₂ -Q ₄ ) and a resistor (R ₈ ) for obtaining an AC power of 2V or more from the DC-DC coil part 2 of the DC-DC coil part 2, and the terminal a of the DC-DC coil part 2; An oscillator circuit (3) consisting of a capacitor (C ₁ ) and a coil (L ₂ ) condenser that outputs 2V of output power by filtering the input when the output of the oscillation circuit (3) is rectified through a diode (D ₁ ) and inputted. And a filter circuit 4 made of (C ₂ to C ₅ ).

In the conventional DC-DC converter circuit configured as described above, when 1.5V power is input through the switching unit 1, the DC-DC coil unit 2 is boosted to 12V or more, and again, AC is 2V or more through the oscillation circuit 3. There is a drawback that power is obtained when the voltage is increased from 1.5V to 12V, resulting in power loss and shortening the battery life due to the low efficiency of the DC-DC converter circuit.

The present invention has been made in view of such a conventional drawback, and an object thereof is to provide a circuit capable of directly boosting an input power of 1.5V to an output power of 2.4V.

Hereinafter, an embodiment of the present invention for achieving such an object will be described in detail with reference to the accompanying drawings.

2 is an input power filter circuit 10 for filtering input power, a power switching circuit 20 for switching power, and an output of the filter circuit 10 and power switching circuit 20. The DC-DC coil part 30 which boosts and receives a voltage, the delay circuit 40 which delays the output of the DC-DC coil part 30, the rectifying circuit 50 which rectifies, and the said rectification circuit 50 A voltage detection and switching circuit 60 for detecting a voltage from the output rectified through the switching circuit and switching the output of the DC-DC coil part 30, and the power switching circuit 20 and the rectifier circuit 50. And an output power supply filter circuit 70 for filtering the output power supply.

3 is a circuit diagram illustrating an embodiment of FIG. 2, wherein the input power filter circuit 10 includes a coil L ¹⁰ and a capacitor C ¹¹ to C ¹⁴ , and the power switching circuit 20 includes a transistor Q ¹⁰ . The DC-DC coil part 30 made of the resistor Q ¹¹ is made of a coil L ¹¹ .

In addition, the delay unit 40 includes a resistor R ¹² (R ¹³ ) and a capacitor C ¹⁵ , and the rectifier circuit 50 includes a diode D ¹⁰ .

In addition, the voltage detection and switching circuit 60 is composed of transistors Q ¹¹ (Q ¹² ) and resistors R ¹³ (R ¹⁴ ), and the output power filter circuit 70 is transistors Q ¹³ and coils (L). ¹² ) and a resistor (R ¹⁵ ) and a capacitor (C ¹⁶ ~ C ¹⁹ ).

In this configuration, 1.5V input power is input to the terminal (b) of the DC-DC coil unit 30 via the input power filter circuit 10. If the switching signal is high (for example, not play or radio) In this case, the transistor Q ¹⁰ of the input power switching circuit 20 and the transistor Q ¹³ of the output power filter circuit 70 are turned off so that the DC-DC converter circuit does not operate as a whole.

However, when the switching signal is low (for example, when playing or radio), the transistor Q ¹⁰ of the input power switching circuit 20 is turned on so that the input power is supplied to the terminal C of the DC-DC coil part 30. At the same time, the transistor Q ¹³ of the output power filter circuit 70 is turned on to output power.

In addition, since the input power applied to the terminal C of the DC-DC coil part 30 is induced to the terminal d through the terminal e, the terminal d takes an AC power of 5 V, which is the rectifier circuit 50. Is converted to DC power through the diode D ¹⁰ .

At this time, when the voltage is 2.4V or more, the transistor Q ¹¹ of the voltage detection and switching circuit 60 is turned on by the zener diode ZD ₁ to operate the delay circuit 40 to operate the DC-DC coil part 30. Power applied to the terminal b is induced to the terminal e.

On the other hand, when the DC power rectified by the diode D ¹⁰ is 2.4V or less, the transistor Q ₁₂ of the voltage detection and switching circuit 60 is induced by the voltage induced at the terminal e of the DC-DC coil part 30. ), The output voltage does not come out because the input power is 0.9V or less and the set does not operate when the input power is 0.9V, so it is not necessary to obtain the output power.

As described above, in the present DC-DC converter circuit, in order to obtain a 2V output power with a 1.5V input power supply, a circuit for boosting more than 12V has to be used separately. Since the voltage is boosted to the output power of V, the efficiency of the DC-DC converter circuit is improved from the existing 31.5% to 50.6% as shown in the fourth diagram, which reduces the current consumption of the set, thereby increasing the battery usage time. .

Claims (1)

An input power filter circuit 10 for filtering input power, a power switching circuit 20 for switching power, and a DC-DC code for boosting the output of the filter circuit 10 and the power switching circuit 20. A part 30, a delay circuit 40 for delaying the output of the DC-DC coil unit 30, a rectifier circuit 50 for converting the AC output of the DC-DC coil unit 30 to direct current; And a voltage detection and switching circuit 60 for detecting a voltage from the output of the rectifier circuit 50 to switch the output of the DC-DC coil unit 30, and the power switching circuit 20, which is switched by the rectifier circuit. A DC-DC converter circuit for headphone stereo, comprising an output power filter circuit 70 for filtering the output power of 50.