CN202260602U

CN202260602U - Power-uninterruptible low-voltage output isolation circuit

Info

Publication number: CN202260602U
Application number: CN2011203930521U
Authority: CN
Inventors: 刘增宏
Original assignee: SHENZHEN HPT ENERGY TECHNOLOGY CO LTD
Current assignee: SHENZHEN HPT ENERGY TECHNOLOGY CO LTD
Priority date: 2011-10-14
Filing date: 2011-10-14
Publication date: 2012-05-30
Anticipated expiration: 2021-10-14

Abstract

The utility model relates to a power-uninterruptible low-voltage output isolation circuit, which comprises at least two power supply systems electrically connected in parallel. Each power supply system has a power supply. The power supplies share a load end. Each power supply system further comprises a metal oxide semiconductor (MOS) tube Q1 and a voltage comparison circuit. The source of the MOS tube Q1 is electrically connected with the output end of the power supply, and the drain of the MOS tube Q1 is electrically connected with the load end of the power supply. The non-inverting input end of the voltage comparison circuit is electrically connected with the source of the MOS tube Q1, the inverting input end of the voltage comparison circuit is electrically connected with the drain of the MOS tube Q1, and the output end of the voltage comparison circuit is electrically connected with the gate of the MOS tube Q1. The voltage comparison circuits are arranged, and the MOS tubes Q1 replace diodes, so that power-uninterruptible output is realized; and simultaneously, when the power supplies output low voltage, circuit loss is low because each MOS tube Q1 has the low voltage drop of several millivolts only.

Description

A kind of power supply does not interrupt the low-voltage output isolation circuit

Technical field

The utility model relates to power technique fields, is specifically related to the unbroken low-voltage output isolation circuit of a kind of power supply.

Background technology

It is as shown in Figure 1 that existing power supply does not interrupt the circuit theory diagrams of output isolation circuit, and power supply (comprises power supply 11 ... Power supply 1n, wherein n is the natural number greater than 1) the parallel connection electric connection; An and shared load end; Be equipped with a diode between the output of each power supply and the load end and (be respectively diode D1 ... Dn, wherein n is the natural number greater than 1), power supply 11 ... When power supply 1n output voltage powers to the load; D1 ... Dn is conducting, sets up output voltage.When power supply 11 ... Power supply 1n is when wherein certain power supply breaks down (power supply damage or voltage be lower than certain limiting value); Break down like power supply 11, D1 ends, and can be powered to the load this moment by power supply 1n keeps output voltage, thereby be embodied as load unbroken voltage output is provided.But in the unbroken output isolation circuit of existing power supply, when the power supply supply power voltage lower, when having only a few volt, because of D1 like supply power voltage ... The conduction voltage drop bigger (about hundreds of millivolt) that Dn is last, this moment, circuit loss was bigger.Thereby when the power supply supply power voltage was low, circuit loss was bigger.

The utility model content

To above-mentioned deficiency, low-loss power supply did not interrupt the low-voltage output isolation circuit when purpose of the utility model was intended to provide a kind of power supply low-voltage to export.

For realizing above-mentioned purpose, the utility model adopts following technical scheme:

A kind of power supply does not interrupt the low-voltage output isolation circuit; Comprise the electric power system that at least two parallel connections electrically connect; Each electric power system is provided with a power supply, said power sharing one load end, and each electric power system also comprises a metal-oxide-semiconductor Q1, a voltage comparator circuit; The source electrode of said metal-oxide-semiconductor Q1 and the output of power supply electrically connect, and its drain electrode electrically connects with the load end of power supply; The source electrode of the in-phase input end of said voltage comparator circuit and metal-oxide-semiconductor Q1 electrically connects, and the drain electrode of its inverting input and metal-oxide-semiconductor Q1 electrically connects, and the grid of its output and metal-oxide-semiconductor Q1 electrically connects.

Preferably; Said voltage comparator comprises comparator U1, resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, capacitor C 1; The output of comparator U1 electrically connects through the grid of resistance R 1 with metal-oxide-semiconductor Q1; The in-phase input end of comparator U1 electrically connects through the source electrode of resistance R 2 with metal-oxide-semiconductor Q1; The inverting input of comparator U1 is through the drain electrode electric connection of resistance R 3 with metal-oxide-semiconductor Q1, the external comparator power supply VCC of the power end of comparator U1, the earth terminal ground connection of comparator U1; Resistance R 5 cross-over connections are between the in-phase input end and output of comparator U1, and capacitor C 1 and resistance R 4 series connection back cross-over connections are between the inverting input and output of comparator U1.

Preferably, said comparator U1 is LM358.

A kind of power supply that the utility model is set forth does not interrupt the low-voltage output isolation circuit, and compared with prior art, its beneficial effect is: the utility model is through setting up voltage comparator circuit; And diode is replaced as metal-oxide-semiconductor Q1; When realizing that power supply does not interrupt exporting, when the power supply low-voltage is exported, because of the pressure drop on the metal-oxide-semiconductor Q1 very little; Have only several millivolts (depending on the conducting resistance of metal-oxide-semiconductor Q1 and the size of current that flows through), circuit loss is very little.

Description of drawings

Accompanying drawing 1 does not interrupt the circuit theory diagrams of output isolation circuit for existing power supply;

Accompanying drawing 2 does not interrupt the circuit theory diagrams of low-voltage output isolation circuit for the utility model power supply.

Embodiment

Below, in conjunction with accompanying drawing and embodiment, the power supply of the utility model is not interrupted the low-voltage output isolation circuit do and further describe, so that clearerly understand the utility model technological thought required for protection.

Accompanying drawing 2 does not interrupt the circuit theory diagrams of low-voltage output isolation circuit for the utility model power supply.As shown in Figure 2, a kind of power supply does not interrupt the low-voltage output isolation circuit, comprises the electric power system that at least two parallel connections electrically connect; In the utility model preferred embodiment, an electric supply system only is shown, this electric supply system comprises a power supply; It is power supply 2; Other do not show an electric power system and shared load end parallelly connected with this electric power system, are example with the electric power system that comprises power supply 2 only here, and the utility model is made an explanation and explains.

This electric power system comprises power supply 2, metal-oxide-semiconductor Q1 and voltage comparator 3.The output of the source electrode of metal-oxide-semiconductor Q1 and power supply 2 (being the A point) electrically connects, and its drain electrode electrically connects with the load end (being the B point) of power supply 2; The source electrode of the in-phase input end of voltage comparator circuit 3 and metal-oxide-semiconductor Q1 electrically connects, and the drain electrode of its inverting input and metal-oxide-semiconductor Q1 electrically connects, and the grid of its output and metal-oxide-semiconductor Q1 electrically connects.Voltage comparator circuit 3 provides high level for the grid of metal-oxide-semiconductor Q1, makes metal-oxide-semiconductor Q1 conducting, and power supply 2 powers to the load, thereby makes load end obtain normal voltage signal.

Voltage comparator 3 comprises comparator U1, resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, capacitor C 1; The output of comparator U1 (being 1 pin of comparator U1) electrically connects through the grid of resistance R 1 with metal-oxide-semiconductor Q1; The in-phase input end of comparator U1 (being 3 pin of comparator U1) electrically connects through the source electrode of resistance R 2 with metal-oxide-semiconductor Q1; The inverting input of comparator U1 (being 2 pin of comparator U1) electrically connects through the drain electrode of resistance R 3 with metal-oxide-semiconductor Q1; The external comparator power supply VCC of the power end of comparator U1 (being 8 pin of comparator U1); The earth terminal of comparator U1 (being 4 pin of comparator U1) ground connection, resistance R 5 cross-over connections are between the in-phase input end and output of comparator U1, and capacitor C 1 and resistance R 4 series connection back cross-over connections are between the inverting input and output of comparator U1.Comparator U1 can adopt LM358 type comparator, can certainly adopt the comparator of other types.

When operate as normal, the output of comparator U1 output high level, for the grid of metal-oxide-semiconductor Q1 provides a high level, metal-oxide-semiconductor Q1 conducting, power supply 2 is to the load normal power supply.When overvoltage occurred, the B point voltage can be higher than A point voltage, and promptly the inverting input voltage ratio normal phase input end voltage of comparator U1 is high, this moment comparator U1 output output low level, metal-oxide-semiconductor Q1 ends, power supply 2 stops rapidly powering to the load.After overvoltage disappeared, it is higher than B point voltage that comparator U1 detects the A point voltage immediately, and comparator U1 output output high level is that the grid of metal-oxide-semiconductor Q1 provides a high level, metal-oxide-semiconductor Q1 conducting, and power supply 2 continues as electric.Because the conversion speed of comparator U1 output between high and low level is very fast, so demonstrate the uninterrupted power supply state in the whole process that power supply 2 powers to the load.Utilize the quick upset of comparator U1 between high and low level here, realized the unbroken low-voltage output of circuit isolation features.

The realization of the low-voltage of low-power consumption output isolation features: if among Fig. 2 during power supply 2 low-voltages (having only several volts) output; Because of the pressure drop on the metal-oxide-semiconductor Q1 very little; Have only several millivolts (depending on the conducting resistance of metal-oxide-semiconductor Q1 and the size of current that flows through); So circuit loss is very little, thereby the low-voltage that has realized low-power consumption is exported isolation features.

For a person skilled in the art, can make other various corresponding changes and distortion, and these all changes and distortion should belong within the protection range of the utility model claim all according to the technical scheme and the design of above description.

Claims

1. a power supply does not interrupt the low-voltage output isolation circuit; Comprise the electric power system that at least two parallel connections electrically connect, each electric power system is provided with a power supply, said power sharing one load end; It is characterized in that; Each electric power system also comprises a metal-oxide-semiconductor Q1, a voltage comparator circuit, and the source electrode of said metal-oxide-semiconductor Q1 and the output of power supply electrically connect, and its drain electrode electrically connects with the load end of power supply; The source electrode of the in-phase input end of said voltage comparator circuit and metal-oxide-semiconductor Q1 electrically connects, and the drain electrode of its inverting input and metal-oxide-semiconductor Q1 electrically connects, and the grid of its output and metal-oxide-semiconductor Q1 electrically connects.

2. power supply according to claim 1 does not interrupt the low-voltage output isolation circuit; It is characterized in that; Said voltage comparator comprises comparator U1, resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, capacitor C 1; The output of comparator U1 electrically connects through the grid of resistance R 1 with metal-oxide-semiconductor Q1, and the in-phase input end of comparator U1 electrically connects through the source electrode of resistance R 2 with metal-oxide-semiconductor Q1, and the inverting input of comparator U1 electrically connects through the drain electrode of resistance R 3 with metal-oxide-semiconductor Q1; The external comparator power supply VCC of the power end of comparator U1; The earth terminal ground connection of comparator U1, resistance R 5 cross-over connections are between the in-phase input end and output of comparator U1, and capacitor C 1 and resistance R 4 series connection back cross-over connections are between the inverting input and output of comparator U1.

3. power supply according to claim 2 does not interrupt the low-voltage output isolation circuit, it is characterized in that, said comparator U1 is LM358.