JP3205731B2 - Automotive socket charger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a socket-type charger for a vehicle, and more particularly to a vehicle power supply which can easily take out a 100V power supply from a commercial outlet simply by inserting it into a DC 12V power supply socket for a cigarette lighter of the vehicle. The present invention relates to a small-sized and light-weight socket-type automobile charger for use in charging a mobile phone with low power and charging a shaver and a secondary battery.

[0002]

2. Description of the Related Art Conventionally, a household 100V outlet has been installed in an automobile, and a 100V, 55Hz rectangular wave voltage has been output via a DC-AC converter or a booster circuit, so that general household appliances and charging devices have been used. Automotive power supplies intended for use in operating electric appliances have been commercialized.

In particular, recently, there has been an increasing need to charge mobile phones, notebook computers, portable magnetic players, transceivers, simple word processors, and the like during traveling time. The number of vehicles installed as options is increasing.

FIG. 4 shows a 15W DC-AC converter as an example of a conventional automobile socket type charger.
In the figure, 1 is DC12V for car cigarette lighter
Power socket 2, harness 3, DC-AC converter, power switch 3 a and 100 V outlet 3 b
By connecting the harness 2 to the power socket 1, the power switch 3a can be turned on and 100V AC can be taken from the outlet 3b.

FIG. 5 shows a circuit configuration of a conventional DC-AC converter 3. In the figure, 3c is a 12V power supply input terminal, 3d is a stabilized power supply circuit, 3e is a step-up transformer, 3f
Is a control IC circuit, 3g is an oscillation circuit, 3h is an overvoltage detection resistor, 3i is an overvoltage protection circuit, and FET1 and FET2 are FE
The T transistor 3j is an output terminal.

A stabilized voltage of DC12V is applied to the center of the primary side of the step-up transformer 3e, and the control IC circuit 3f
Is the oscillation voltage from the oscillation circuit 3g, FET1, FET2
Are alternately turned on and off, a rectangular wave of 400 Hz AC 100 V is generated on the secondary side of the step-up transformer. Ideally, the frequency at this time is 50 to 60 Hz. In that case, however, a large boosting transformer is required even with an output of 15 W. Therefore, when the frequency is increased to about 400 Hz, the efficiency of the step-up transformer is increased and the size can be reduced.

If the above-mentioned DC-AC converter is limited to a charger, it can be charged even with a rectangular wave of 400 Hz, but it may not be practical for other uses.

[0008]

The above-mentioned conventional socket-type charger for automobiles has a step-up transformer size,
Due to the effect of weight, a fixed mounting space is required even with a small power supply of about 15 W.

However, there are many vehicles which are not equipped with the above-mentioned vehicle power supply at present. As a matter of fact, it is annoying for drivers who consider it unnecessary. This is because many of the power supplies are large and heavy, including transformers, and have the downside of generating noise and cooling fans. Also, the cost is greatly increased.

As a matter of fact, it is not reasonable to attach a large and heavy 100 W power supply to charge a mobile phone that can be charged at 10 W or less. Therefore, a telephone charger dedicated to one model has been put into practical use, although a step-down power supply dedicated to the model is mounted, the voltage is reduced from 12 V to about 2 to 3 V, and it is not compatible with various connectors. In this case, the mobile phone is small and lightweight, but cannot handle a wide variety of mobile phones. Therefore, it is necessary to replace the charger every time the mobile phone is replaced.

Therefore, a small 100 V power supply in which the number of W is reduced to 15 W or less has been put to practical use. This will work with any mobile phone. However, a transformer is indispensable to boost the AC voltage to 100 V, and although it is small, it has a certain weight, and after all, a device from the cigarette lighter socket to the 100 V outlet via harnesses is required. The wiring of the harnesses from the cigar lighter socket itself is troublesome, such as obstructing driving, and the mounting place is still troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight socket-type charger for a vehicle which does not require a step-up transformer and does not need to draw harnesses from a cigarette lighter socket.

[0013]

In order to achieve the above object, an automobile socket type charger according to the present invention comprises a plug which can be inserted into and detached from a DC power socket for a cigarette lighter of an automobile, and a DC minus plug connected to the plug. Booster circuit,
A booster circuit comprising any one of a DC plus booster circuit, and a commercial outlet connected to an output of the booster circuit , wherein the booster circuit and the commercial outlet are integrated into the plug. I do.

In the present invention, the booster circuit generates a P-channel FET connected to the plug, a choke coil connected to the P-channel FET, a control IC circuit for controlling the P-channel FET, and the choke coil. It may be constituted by a smoothing circuit for rectifying the surge voltage into a DC voltage.

Further, in the present invention, the booster circuit includes a choke coil connected to the plug, an N-channel FET connected to the choke coil, and a smoothing circuit for rectifying a surge voltage generated by the choke coil into a DC voltage. May be configured.

[0016]

FIG. 1 shows an embodiment of a socket-type charger for a vehicle according to the present invention. In the figure, 1
0 is a power socket of 12V DC for car cigarette lighter, P1 (P2, P3) is a plug that can be inserted into and removed from the power socket, and 12 is an AC integrated into the plug P1 (P2, P3). Commercial outlet, 13 printed circuit board, 14 fuse, 15 light emitting diode, 2
Reference numeral 0 denotes an input terminal provided at the tip of the plug P1 (P2, P3), reference numeral 20a denotes a spring for biasing the input terminal 20, and reference numeral 21 denotes an elastic ground terminal provided on an outer peripheral portion of the plug P1 (P2, P3). is there. When the plug P1 (P2, P3) is inserted into the power socket 10, the reinforcing cushion member 16 is mounted as shown in the figure to fix the plug P1 (P2, P3). The outlet insertion / removal surface 12a of the AC commercial outlet 12 is tapered, and the light emitting diode 15 emits green light when the automobile socket type charger can be used normally and emits red light when it cannot be used. . In addition, the light emitting diode 15 may be only for green light, and may not be for red light.

FIG . 2 shows a DC-DC converter circuit formed on the plug P1 and the printed circuit board 13. In the figure, P1 is a plug, 11a is a DC minus booster circuit, 12 is a commercial outlet for AC, 15 is the light emitting diode, 20 is an input terminal of a 12V DC power supply for cigar lighter, 21 is a ground terminal, 22 is a protection diode, 23 Is a PWM (pulse width modulation) control IC circuit, 24 is a P-channel FET, 25 is a choke coil, 26 is a smoothing circuit, and includes a diode D1 and a capacitor C1. 27
Is an output voltage dividing resistor, 28 is an output voltage feedback path, 29 is a load connected to the outlet, 30 is a secondary battery, and 31 is a full-wave rectifier circuit composed of four diodes.

When the plug P1 is inserted into the power socket 10 of the cigarette lighter DC 12V, a DC 12V voltage is applied to the above-described DC-DC converter circuit, and the PWM control IC circuit 23 starts oscillating, thereby turning on the P-channel FET 24. , Repeat off. P channel F
Since the choke coil 25 downstream of the ET 24 has a low impedance, a large current flows when the P-channel FET 24 is turned on. The on and off frequencies are high (Equation 1)
(0 kHz), the on-time current value is affected by the inductance of the choke coil 25, and increases as the on-time increases.

At the moment when the P-channel FET 24 is turned off,
A back electromotive voltage is generated from the choke coil 25 and is -100 V
The above surge voltage 32 is obtained. Each second, tens of thousands of surge voltages 32 are generated, and the surge voltages 32 are
When the current is integrated in addition to the capacitor C1 through the capacitor 1, a direct current of -100 V is generated. This -100 V is divided by a voltage dividing resistor 27.
, And the feedback is performed via the path 28, and while the PWM control IC circuit 23 monitors the
By performing duty control on the ON time at M, the output voltage of -100 V can be made constant regardless of the load.
The output voltage of -100 V is applied to the secondary battery 30.

When the secondary battery 30 includes the full-wave rectifier circuit 31, such as a mobile phone charger, a current flows through the secondary battery 30 in the leftward direction. Is the same. The same direction is applied when AC100V is applied. In the end, the converter circuit of FIG. 2 can charge many mobile phones using a full-wave rectifier circuit, a shaver, a charger for a secondary battery, and the like. Further, in the converter circuit, since the diode D1 is directed leftward (forward direction), the DC 12V voltage does not short-circuit deadly and is safe. In addition, the PWM control IC circuit 23 stops oscillation when an abnormality occurs, thereby ensuring safety.

FIG . 3 shows another example of the configuration of the DC-DC converter circuit. The same reference numerals as those in FIG. 2 denote the same or similar circuits, P2 denotes a plug, 11b denotes a DC plus booster circuit,
4 'is an N-channel FET, a DC plus booster circuit 11
The choke coil 25 which constitutes a part of b is connected to the upstream side of the N-channel FET 24 ', and the back electromotive voltage (surge voltage) 32' generated by this is not minus but plus 100V.

[0022]

As is apparent from the above description, the present invention provides the following practically excellent effects. (I) Many of mobile phones, shavers, and secondary batteries that can be charged only with a household 100V power supply can be charged in a car and become an outlet integrated with a cigarette lighter socket. A lightweight, unobtrusive power supply is obtained. (Ii) By charging around minus 100V DC,
The diode is safe because the diode blocks current even in the event of a dead short of the load.

[Brief description of the drawings]

FIG. 1A is a schematic configuration diagram of an embodiment of an automotive socket-type charger of the present invention, and FIG. 1B is a front view thereof.

FIG. 2 is a circuit diagram showing a configuration example of a DC-DC converter circuit in the embodiment.

FIG. 3 is a circuit diagram showing another configuration example of the DC-DC converter circuit.

FIG. 4 is an outline of a conventional automobile socket-type charger.
It is a block diagram .

FIG. 5 is a configuration diagram of a conventional DC-AC converter circuit.
There is .

[Explanation of symbols]

 Reference Signs List 10 Power socket for cigarette lighter 11a DC minus booster circuit 11b DC plus booster circuit 12 AC commercial outlet 13 Printed circuit board 23 PWM control IC circuit 24 P-channel FET 25 Choke coil 31 Full-wave rectifier circuit P1, P2 plug

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02J ⁷ /00-7/12 H02J 7/34-7/36 B60R 16/00-17/02

Claims (3)

(57) [Claims] 1. A plug that can be inserted into and removed from a DC power socket for a cigar lighter of an automobile, a DC minus booster circuit connected to the plug, and a DC plug.
And a commercial outlet connected to an output of the booster circuit , wherein the booster circuit and the commercial outlet are integrated into the plug. Socket charger for automobiles. 2. The booster circuit includes a P-channel FET connected to the plug, a choke coil connected to the P-channel FET, a control IC circuit for controlling the P-channel FET, and a surge voltage generated by the choke coil. 2. An automotive socket-type charger according to claim 1, comprising a smoothing circuit for rectifying the voltage to a DC voltage. 3. The booster circuit includes: a choke coil connected to the plug; and a choke coil connected to the choke coil.
2. A socket charger for an automobile according to claim 1, comprising a channel FET and a smoothing circuit for rectifying a surge voltage generated by said choke coil into a DC voltage.