CN2279647Y - Notebook PC Power Supply - Google Patents

Abstract

The power supply unit installed inside the notebook computer casing consists of input rectifier, pi-type filter, inverter, output rectifier circuit and output protecting circuit connected serially. The output of the output protection circuit is connected with the control end of a switch oscillating tube in the inverter, and two ends of a grid bias resistor of the switch oscillating tube in the inverter are connected in parallel with an accelerating circuit formed by serially connecting an accelerating resistor and an accelerating capacitor. The utility model discloses with the direct current side of pi type filter setting after the input rectifier, reduced generate heat and electric leakage, can reach the effect of reducing the volume, and accelerating circuit has shortened the switch delay time of switch oscillation pipe again, can reduce the consumption of switch tube and generate heat. The power supply and the computer motherboard can be integrated into a whole by the above measures and is contained in the computer case.

Description

Notebook PC Power Supply

The utility model relates to a power supply device installed in a case of a notebook computer.

Today's portable computers include laptops, notebooks, and palmtops, all of which have external power supplies. The external power supply is composed of a π-type filter, an input rectifier, an inverter, an output rectification circuit, and an output protection circuit connected in series in sequence, and the π-type filter is composed of a noise filter and a filter capacitor. After it converts the mains electricity into direct current, it sends it to the power jack of the notebook computer case through the cable, and then through the power distributor in the case, one way supplies the main board of the computer, and the other way passes through the charging circuit to charge the battery in the case. In this way, when carrying a notebook computer to go out, it is necessary to carry a power supply at the same time, which takes up a lot of space, and the design of the two independent shells is likely to miss the power supply due to negligence, so it is very inconvenient to use. .

If the power supply is integrated with the computer, the above problems can be solved, but there are two problems with this external power supply: 1. The noise filter is connected to the AC side, and a large current flows through it. The temperature generated by the iron core is quite high, so a larger iron core is required to meet the heat dissipation requirements, but the size of the filter cannot be reduced, so it cannot be accommodated in the computer case, and in addition, the heat will affect the stable operation of the host The leakage and heat generated by the filter capacitor may also affect the normal operation of the host. 2. The switching delay of the switching oscillation tube in the inverter is relatively large, which will generate considerable heat. Therefore, it is impossible to integrate the power supply and the computer without solving the above-mentioned problems such as space occupation, electric leakage, and heat generation.

In view of the above, the utility model will provide a power supply that occupies a small space, does not leak electricity, and can reduce heat generation. The power supply can be integrated with the motherboard of a computer.

In order to achieve this purpose, the utility model adopts the following technical solutions: notebook computer power supply, including π-type filter, input rectifier, inverter, output rectifier circuit, output protection circuit, inverter, output rectifier circuit, output The protection circuits are connected in series sequentially, and the output of the output protection circuit is connected to the control terminal of the switch oscillation tube in the inverter, and it is characterized in that: the π-type filter is connected in series between the output of the input rectifier and the input of the inverter Between; two ends of the gate bias resistor of the switching oscillation tube in the inverter are connected in parallel with an acceleration circuit composed of an acceleration resistor and an acceleration capacitor in series.

In the utility model, the π-type filter is arranged on the DC side after the input rectifier, which reduces heat generation and leakage, so the effect of reducing the volume can be achieved, and the acceleration circuit shortens the switching delay time of the switching oscillation tube, so the switching tube can be reduced. power consumption and heat generation. The above measures can integrate the power supply unit with the computer motherboard.

Below in conjunction with accompanying drawing, the utility model is further described.

FIG. 1 is a circuit diagram of an external power supply;

Fig. 2 is the circuit diagram of the utility model.

The external power supply in Figure 1 is composed of a π-type filter, an input rectifier BD, an inverter, an output rectification circuit, and an output protection circuit connected in series. The output of the output protection circuit is connected to the switch oscillation tube in the inverter. Control terminal. Among them: the π-type filter is composed of noise filter NF3 and filter capacitors CY11 and CY21; the inverter is composed of Q11, Q21, Q31 and their peripheral circuits, Q11 is the switching oscillation tube of the inverter, and its output is connected to the original of the transformer side (in the figure, the transformer and its original secondary side are represented by a thick black line), Q31 and Q21 connected in series constitute the control stage of the switching oscillator Q11; the output rectifier circuit connected from the secondary side of the transformer is composed of a rectifier diode D51, a filter The half-wave rectification filter circuit composed of inductor L1 and filter capacitor C121 outputs +12V DC; the output protection circuit is composed of comparators U2A1 and U2B1, optocoupler U11 and peripheral circuits. When the output is overloaded, the light-emitting tube of U11 lights up, and the conduction time of the switch tube Q11 is controlled by the light-receiving tube of U11 connected to the base of the switch tube control stage Q31, thereby automatically adjusting the output voltage. The disadvantages of this circuit have been described above.

Please refer to accompanying drawing 2, the utility model is formed by serial connection of input rectifier BD1, π type filter, inverter, output rectification circuit, output protection circuit successively, the output of output protection circuit connects the control end of inverter. Among them: the π-type filter is composed of noise filter NF and filter capacitors C1, C7, and C45; Q1~Q3 and their peripheral circuits in the lower left part of the figure constitute the inverter, and Q3 is the switching oscillator in the inverter. Its output is connected to the primary side of the transformer T1, Q1 and Q2 constitute the control stage of the switching oscillator Q3; the output rectifier circuit connected from the secondary side of the transformer T1 is composed of a rectifier diode D3, a filter inductor L1, and filter capacitors C11~C13, etc. The half-wave rectifier circuit can output +18V DC; the output protection circuit located in the lower right part of the figure is composed of two LM358 comparators, optocoupler PC1 and peripheral circuits. When the output is overloaded, the light-emitting tube of PC1 lights up, and the conduction time of the switch tube Q3 is controlled by the light-receiving tube of PC1 connected to the base of the switch tube control stage Q1, thereby automatically adjusting the output voltage. The circuit is integrated with the motherboard of the notebook computer, and is accommodated in the computer main box.

Each unit circuit in the utility model is basically similar to that in Fig. 1, and there are two points of difference: 1. The π-type filter is arranged after the input rectifier BD1; An acceleration circuit composed of an acceleration resistor R80 and an acceleration capacitor C60 in series is connected in parallel to the terminal, wherein the resistance of R2 is about 1KΩ, the resistance of R80 is about 100Ω, and the capacity of C60 is about 0.1μF.

Since the noise filter NF is set on the DC side after the input rectifier, only the DC power and the noise in the DC power flow through it, and there is no problem of large current on the AC side in the external power supply, and the heat generated by it is relatively low and can be used more efficiently. The small iron core structure can achieve the effect of reducing the volume, and can ensure the same effect of filtering noise. The filter capacitors C1, C7, and C45 connected to the noise filter are also located on the terminals of the DC power supply, and the leakage of the capacitors on the DC power supply is extremely low, so it can solve the problem caused by the external power supply located on the AC side. Leakage and leakage-derived heating problems can ensure its stability and service life.

After the acceleration circuit is added, when the switch tube Q3 is turned from off to on, the direct current provides bias current to the gate of Q3 through the acceleration capacitor C60 and the acceleration resistor R80 and charges C60, because the impedance of the acceleration circuit is much smaller than the bias resistor The resistance value of R2, so Q3 is turned on quickly, and its turn-on time is greatly shortened. When the acceleration capacitor C60 is fully charged, the acceleration circuit is disconnected. At this time, the original bias resistor R2 is immediately supplied with a lower gate bias voltage, so the switch tube Q3 is turned from on to off. Due to the large resistance of R2 , so Q3 ends quickly, and its turn-off time is greatly shortened. Since the switching delay time of the switch tube is shortened, the power consumption and heat generation of the switch tube can be reduced.

Because the volume of the π-type filter is reduced, the calorific value is reduced, and there is no leakage phenomenon, and the acceleration circuit reduces the power consumption and calorific value of the switch tube, the utility model can be integrated with the main board of a notebook computer and stored in Inside the main computer case.

Claims (3)

1. notebook computer power supply unit; comprise pi type filter, input rectifier, inverter, output rectification circuit, output protection circuit; inverter, output rectification circuit, output protection circuit are connected in series successively; the output of output protection circuit connects the control end of switch oscillating tube in the inverter, it is characterized in that:

Described pi type filter is serially connected between the input of the output of described input rectifier and described inverter;

The gate bias resistor two ends of a switch oscillating tube accelerating circuit that constitutes by accelerating resistor and speed-up capacitor series connection in parallel in the described inverter.

2. notebook computer power supply unit as claimed in claim 1 is characterized in that: the resistance of described accelerating resistor is 100 Ω.

3. notebook computer power supply unit as claimed in claim 1 is characterized in that: the capacity of described speed-up capacitor is 0.1 μ F.

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