CN200969057Y

CN200969057Y - Undervoltage canceling circuit

Info

Publication number: CN200969057Y
Application number: CN 200620158574
Authority: CN
Inventors: 卢作烜; 李小宇
Original assignee: BEIJING XINLEINENG Co Ltd
Current assignee: Beijing Suplet Co., Ltd.
Priority date: 2006-11-24
Filing date: 2006-11-24
Publication date: 2007-10-31
Anticipated expiration: 2016-11-24

Abstract

The utility model discloses an under voltage compensation circuit, which comprises an output filtration, a high voltage detector, a PWM controller, a driving circuit, a circuit sampler, a voltage sampler, a filtration circuit and an energy storage capacitor. Through the topological boost property of the BOOST circuit, when the input voltage is low, the voltage will be raised; when the input voltage is high, the input will be directly provided for the output. If the utility model is used through being serially connected with the switch power, the narrowed input range circuit can work in a wide input range of a lower input voltage. The BOOST circuit is used in particular for raising the voltage, because of non-isolation and without transformer loss, the efficiency is very high. The utility model can be simply realized and conveniently used, which can reduce the transformation cost.

Description

Under-voltage compensating circuit

Technical field

The utility model relates to a kind of power circuit, specifically, relates to a kind of under-voltage compensating circuit of Switching Power Supply front end.

Background technology

At first, power to Switching Power Supply with battery in the tank power-supply system, cell voltage generally is 20V～30V, and under situations such as turning, cell voltage can drop sharply to 9V, and this moment, equipment also needed operate as normal.The ability of operate as normal when for this reason, Switching Power Supply needs low input.At present, in other mobile device, similar demand is also arranged as power-supply systems such as automobile, steamer, aircrafts.

For lower-powered Switching Power Supply, be not difficult to realize above-mentioned requirements with anti-sharp topology, but the difficulty that realizes for large power supply is just bigger.Power supply requirement is ever-changing, all makes a special wide input range power supply for each demand, and cost is too high, wastes excessive.If can make a kind of power supply changeover device, when input voltage is low, voltage is raised; When input voltage was high, input voltage was directly exported.So,, satisfy the various power supply requirements of wide input range as long as the marginal compensator of several different capacity grades just can make up with the regular tap power supply.

The utility model content

A kind of under-voltage compensating circuit that is applied to the Switching Power Supply input end that the utility model designs in order to solve the problems of the technologies described above just.

The technical scheme that its technical matters that solves the utility model adopts is:

A kind of under-voltage compensating circuit comprises input filtering, high pressure detection, PWM controller, driving circuit, current sampling, voltage sampling and filtering circuit and storage capacitor.Power input links to each other with diode D2 is anodal with the input end that input filtering, high pressure detect, and the control end of PWM controller links to each other with the output terminal of high pressure detection, current sampling and voltage sampling; The output terminal of PWM controller links to each other with the driving circuit input end, the grid of driving circuit output termination switch MOS pipe Q1, the source electrode of Q1 links to each other with the current sampling input end, the coupled end of coupled apparatus links to each other with diode D1 is anodal, the drain electrode of switch MOS pipe Q1 links to each other with the coupled end of coupled apparatus, and input filtering output connects the input end of coupled apparatus; The negative pole of diode D1, D2 links to each other with the input end of voltage sampling input end and filtering circuit and storage capacitor; Filtering circuit and storage capacitor output connect the input of regular tap power supply.

The coupled apparatus of described under-voltage compensating circuit is energy storage inductor L1, and the coupled end of energy storage inductor L1 links to each other with diode D1 is anodal, and the drain electrode of switch MOS pipe Q1 links to each other with the coupled end of energy storage inductor L1, and input filtering output connects the input end of energy storage inductor L1.

The coupled apparatus of described under-voltage compensating circuit is for being single-circuit transformer T1, the coupled end of single-circuit transformer T1 links to each other with diode D1 is anodal, the drain electrode of switch MOS pipe Q1 links to each other with the centre tap of single-circuit transformer T1, and input filtering output connects the input end of single-circuit transformer T1.

Do a modular power source with the under-voltage compensation of the utility model (BOOST) circuit, this power supply has several characteristics.At first, when cell voltage falls, the BOOST circuit start, input voltage is raise to the circuit supply of back, this process must be enough short, cooperate suitable storage capacitor, make the circuit of back that a continual high voltage be arranged, so the output when BOOST starts Time Created must be very short.Secondly, the BOOST circuit only every a diode and inductance, when input voltage is sufficiently high, only need be turned off PWM and just can directly supply with output to input between the input and output when PWM is idle.In order to reduce loss as far as possible, be connected in parallel on the BOOST circuit with a less diode of conduction voltage drop again.When the PWM of BOOST circuit turn-offs, when input and output are in following state because this moment the input voltage height, practical devices withstand voltage is taller than operate as normal the time.So the device of power supply mainly is that electric capacity etc. is withstand voltage will enough allowances.Certainly, the output voltage of BOOST exceeds certain allowance than the minimum operating voltage of back circuit.

The beneficial effects of the utility model are: make a kind of power supply changeover device that compensation low pressure effect is arranged, can use with the series connection of regular tap power supply, make the Switching Power Supply of narrow input range become wide input range.The BOOST circuit is used for boosting specially, because non-isolation does not have transformer loss, so efficient is very high.This circuit is realized simple, and is flexible and convenient to use, can effectively reduce the power supply improvement cost.

Description of drawings

Fig. 1 is the utility model one embodiment schematic block circuit diagram.

Fig. 2 is another embodiment schematic block circuit diagram of the utility model.

Embodiment

Below in conjunction with drawings and Examples the utility model is further specified.

Embodiment one

As shown in Figure 1, a kind of under-voltage compensating circuit that adopts energy storage inductor can be realized the performance of output 24V of maximum 150W, the minimum 9V of input.Comprise input filtering, high pressure detection, PWM controller, driving circuit, current sampling, voltage sampling and filtering circuit and storage capacitor.Power input links to each other with diode D2 is anodal with the input end that input filtering, high pressure detect, and the control end of PWM controller links to each other with the output terminal of high pressure detection, current sampling and voltage sampling; The output terminal of PWM controller links to each other with the driving circuit input end, the grid of driving circuit output termination switch MOS pipe Q1, the source electrode of Q1 links to each other with the current sampling input end, and pin of the drain electrode of Q1 and energy storage inductor L1 links to each other with diode D1 is anodal, and input filtering output connects another pin of L1; The negative pole of diode D1, D2 links to each other with the input end of voltage sampling input end and filtering circuit and storage capacitor; Filtering circuit and storage capacitor output connect the input of regular tap power supply.

Wherein diode D1, D2 are the 30CTQ060S PBF of IR company, and switch MOS pipe Q1 is the IRF2807S PBF of IR company, and energy storage inductor L1 is the customization inductance of EI18 magnetic material 7 circle 5uH.

Embodiment two

As shown in Figure 2, a kind of under-voltage compensating circuit that adopts single-circuit transformer can be realized the performance of output 40V of maximum 150W, the minimum 9V of input.Comprise input filtering, high pressure detection, PWM controller, driving circuit, current sampling, voltage sampling and filtering circuit and storage capacitor.Power input links to each other with diode D2 is anodal with the input end that input filtering, high pressure detect, and the control end of PWM controller links to each other with the output terminal of high pressure detection, current sampling and voltage sampling; The output terminal of PWM controller links to each other with the driving circuit input end, the grid of driving circuit output termination switch MOS pipe Q1, the source electrode of switch MOS pipe Q1 links to each other with the current sampling input end, the drain electrode of switch MOS pipe Q1 links to each other with the centre tap of single-circuit transformer T1, the pin of single-circuit transformer T1 links to each other with diode D1 is anodal, and the output of input filtering connects another pin of single-circuit transformer T1; The negative pole of diode D1, D2 links to each other with the input end of voltage sampling input end and filtering circuit and storage capacitor; Filtering circuit and storage capacitor output connect the input of regular tap power supply.

Wherein diode D1 is that MBRB20100CT PBF, the D2 of IR company are the 30CTQ060S PBF of IR company, and switch MOS pipe Q1 is the IRF2807S PBF of IR company, and single-circuit transformer T1 is an EI18 magnetic material 7+5 circle, and 7 circles are 5uH.

The utility model is not limited to above-mentioned preferred forms, and other any identical with the utility model or akin products that anyone draws under enlightenment of the present utility model all drop within the protection domain of the present utility model.

Claims

1, a kind of under-voltage compensating circuit comprises input filtering, high pressure detection, PWM controller, driving circuit, current sampling, voltage sampling and filtering circuit and storage capacitor; It is characterized in that: power input links to each other with diode (D2) is anodal with the input end that input filtering, high pressure detect, and the control end of PWM controller links to each other with the output terminal of high pressure detection, current sampling and voltage sampling; The output terminal of PWM controller links to each other with the driving circuit input end, the grid of driving circuit output termination switch MOS pipe (Q1), the source electrode of switch MOS pipe (Q1) links to each other with the current sampling input end, the coupled end of coupled apparatus links to each other with diode (D1) is anodal, the drain electrode of switch MOS pipe (Q1) links to each other with the coupled end of coupled apparatus, and input filtering output connects the input end of coupled apparatus; The negative pole of diode (D1, D2) links to each other with the input end of voltage sampling input end and filtering circuit and storage capacitor; Filtering circuit and storage capacitor output connect the input of regular tap power supply.

2, under-voltage compensating circuit according to claim 1, it is characterized in that: described coupled apparatus is energy storage inductor (L1), the coupled end of energy storage inductor (L1) links to each other with diode (D1) is anodal, the drain electrode of switch MOS pipe (Q1) links to each other with the coupled end of energy storage inductor (L1), and input filtering output connects the input end of energy storage inductor (L1).

3, under-voltage compensating circuit according to claim 1, it is characterized in that: described coupled apparatus is single-circuit transformer (T1), the coupled end of single-circuit transformer (T1) links to each other with diode (D1) is anodal, the drain electrode of switch MOS pipe (Q1) links to each other with the centre tap of single-circuit transformer (T1), and input filtering output connects the input end of single-circuit transformer (T1).