CN203166465U

CN203166465U - Overvoltage protection circuit

Info

Publication number: CN203166465U
Application number: CN 201320099829
Authority: CN
Inventors: 阮仕涛
Original assignee: Shenzhen Prafly Technology Co Ltd
Current assignee: Shenzhen Prafly Technology Co Ltd
Priority date: 2013-03-05
Filing date: 2013-03-05
Publication date: 2013-08-28
Anticipated expiration: 2023-03-05

Abstract

Provided is an overvoltage protection circuit, comprising a voltage monitoring module (1) used to detect voltage and output monitoring output signals, an overvoltage detection and latch module (2) connected with the voltage monitoring module (1) and used to receive the monitoring output signals and output latch signals, a power input control module (3) connected with the overvoltage detection and latch module (2) and performs power input control according to the latch signals, and an LED indicator module (4) connected with the overvoltage detection and latch module (2) and performs indication according to the latch signals. The circuit detects a plurality of branch voltage, if only one or more detected voltage exceeds a maximum set value, a main power supply access is cut off immediately, and LED lamplight indication is given out, thereby effectively protecting electronic products. The overvoltage protection circuit is simple in setting.

Description

A kind of overvoltage crowbar

Technical field

The utility model relates to the circuit design technique field, relates in particular to a kind of overvoltage crowbar.

Background technology

In design of electronic products, power supply is one of of paramount importance design part wherein normally, and it is directly connected to reliability of products and stability.Because abnormity of power supply causes equipment component to burn the most serious accident of electronic product often.Present electronic product power supply design, overvoltage or the overcurrent protection of having only the one-level control chip to carry at each branch power supply usually damaged but still have because electric voltage exception causes product.

Summary of the invention

The technical problems to be solved in the utility model is, causes the defective of product damage etc. at prior art unusually because carrying overvoltage protection, and a kind of overvoltage crowbar is provided.

The technical scheme that its technical problem that solves the utility model adopts is: provide a kind of overvoltage crowbar, the overvoltage detecting that comprising is connected for the voltage monitoring module of detecting voltage and output monitoring output signal, with the voltage monitoring module takes into custody control output signal and output latch signal and latch module, the LED indicating module that links to each other with latch module and carry out power supply input control module that the power supply input controls, link to each other with latch module and indicate according to latch signal with the overvoltage detecting according to latch signal with the overvoltage detecting.

Preferably, described voltage monitoring module is for detecting a plurality of Zener diodes of a plurality of branches voltage simultaneously.

Preferably, the reverse-conducting voltage of described Zener diode is more than 1.1 times of branch's voltage.

Preferably, described voltage monitoring module output monitoring output signal when detecting one or more branches voltage.

Preferably, described latch signal is low level signal.

Implement overvoltage crowbar of the present utility model, have following beneficial effect: by the detecting to a plurality of branches voltage, when wherein one or more exceed maximum set value when the voltage of detecting, cut off the main power source path immediately, and send the indication of LED light; Before the user cuts off external power supply, keep main power source to open circuit, effectively protect electronic product not burnt by further overvoltage, and keep on-the-spot with to be analyzed; Monitor the multiple power supplies voltage status simultaneously, to the whole power supply increase first class of protection of electronic product, applicability is extremely wide; Arrange simply, less to the influence of construction cycle, certain advantage is arranged on cost and the applicability.

Description of drawings

In order to be illustrated more clearly in the technical scheme of the utility model embodiment, the accompanying drawing of required use is done simple the introduction in will describing embodiment below, obviously, accompanying drawing in describing below only is embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings, in the accompanying drawing:

Fig. 1 is the structural representation of the utility model overvoltage crowbar embodiment;

Fig. 2 is the voltage monitoring module circuit diagram of the utility model overvoltage crowbar embodiment;

Fig. 3 is overvoltage detecting and the latch module circuit diagram of the utility model overvoltage crowbar embodiment;

Fig. 4 is the power supply input control module circuit diagram of the utility model overvoltage crowbar embodiment;

Fig. 5 is the LED indicating module circuit diagram of the utility model overvoltage crowbar embodiment.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer, the various embodiment that hereinafter will describe will be with reference to corresponding accompanying drawing, these accompanying drawings have constituted the part of embodiment, have wherein described and have realized the various embodiment that the utility model may adopt.Should understand, also can use other embodiment, perhaps this paper listed examples be carried out modification on the 26S Proteasome Structure and Function, and can not break away from scope of the present utility model and essence.

As shown in Figure 1; in a kind of overvoltage crowbar embodiment that the utility model provides, the overvoltage detecting that comprising is connected for the voltage monitoring module 1 of detecting voltage and output monitoring output signal, with voltage monitoring module 1 takes into custody control output signal and output latch signal and latch module 2, the LED indicating module 4 that links to each other with latch module 2 and carry out power supply input control module 3 that the power supply input controls, link to each other and indicate according to latch signal with latch module 2 with the overvoltage detecting according to latch signal with the overvoltage detecting.

Wherein, voltage monitoring module 1 is used for detecting simultaneously a plurality of branches voltage, and produces the monitoring output signal in real time, and overvoltage detecting and latch module 2 receive the monitoring output signal that voltage monitoring module 1 produces, and it is analyzed, compare with predefined corresponding maximum voltage value.When wherein one or more branch's voltages have when unusual, overvoltage detecting and latch module 2 produce low level signals, when the abnormal signal low level, generate the low level signal that latchs, be used for preserving on-the-spot, with usefulness to be analyzed, and the output latch signal.Power supply input control module 3 receives the latch signal of overvoltage detecting and latch module 2 outputs, and main power source is disconnected, and simultaneously, LED indicating module 4 also sends the LED indication according to latch signal.

The branch power supply that has multiple external power supply conversion back to generate on the general mainboard uses for CPU, bridge sheet or IO.This circuit can once be detected at the chip part changing voltage of emphasis, also can detect the voltage that generates after whole conversions.As shown in Figure 2, voltage monitoring module 1 is Zener diode, is example with mainboard voltage commonly used: choose the Zener diode of corresponding voltage according to detecting voltage, the principle of generally choosing is that Zener diode reverse-conducting voltage is more than 1.1 times of voltage of detecting.After detecting voltage has one or more overvoltage to reach 1.1 times, diode reverse breakdown.

As shown in Figure 3, after the Zener diode of Fig. 2 is breakdown, by the electric current of Q109 the 5th pin Q109 left-half triode is opened, Q109.3 place level is 0, Q1072～3 pin conductings, Q1062～3 conductings subsequently, + VDC_L output voltage is to Q108.1, and Q1082～3 conductings, OVP_SHUT# are 0.In said process, after Q1072～3 conductings, the voltage at Q109.2 place is about (+VDC_L-0.7) * 47/ (47+20), general adapter is 12V and 19V at present, so the voltage at Q109.2 place is minimum approximately to be 7.9V, and the right half of triode of Q109 is opened, the right half part of Q109 will be in open mode always like this, and Q107 also is in open mode always.Even the overvoltage partial circuit on the mainboard is closed or damaged at this moment, by the not output of Fig. 2 diode, it is 0 state that this partial circuit also can keep OVP_SHUT# always, unless external power source+VDC_L is removed, realizes latching.

Voltage in detecting all is that Q109 the situation that triode is opened can not take place under the normal condition.Q108 is in closed condition always, and this group circuit is finally exported OVP_SHUT# and is in vacant state.

As shown in Figure 4, PCN2 is the input interface (namely plug in adapter or give the input port of main board power supply power supply) of external power source, except OVP_SHUT# is 0 o'clock, the D of other any state Q49～S level is in conducting state, external power source can normally be input to mainboard, when Fig. 2 generation overvoltage, when the j by Fig. 3 is latched as low level with OVP_SHUT#, D～S of Q49 can not conducting, and external power source will be cut off to the path of mainboard.Because the state of OVP_SHUT# is latched, unless pull out external power supply, after overvoltage has taken place, can be cut off to the input channel of mainboard always.

As shown in Figure 5, when the OVP_SHUT# low level, Q112D～S conducting, LED10 electrified light emitting.Because the state of OVP_SHUT# is latched, unless pull out external power supply, after overvoltage had taken place, LED10 can be luminous always.

Overvoltage crowbar of the present utility model can be applicable to desktop computer mainboard, notebook mainboard, panel computer mainboard and/or cell phone mainboard etc.

The utility model overvoltage crowbar, by the detecting to a plurality of branches voltage, as long as the voltage of detecting wherein one or more when exceeding maximum set value, cut off the main power source path immediately, and send the indication of LED light.Before the user cuts off external power supply, keep main power source to open circuit, effectively protect electronic product not burnt by further overvoltage, and keep on-the-spot with to be analyzed.Can monitor the multiple power supplies voltage status simultaneously on the basis cheaply, to the whole power supply increase first class of protection of electronic product, applicability is extremely wide; Arrange simply, less to the influence of construction cycle, certain advantage is arranged on cost and the applicability.

The above only is preferred embodiment of the present utility model, and those skilled in the art know, under the situation that does not break away from spirit and scope of the present utility model, can carry out various changes or be equal to replacement these features and embodiment.In addition, under instruction of the present utility model, can make amendment to adapt to concrete situation and material to these features and embodiment and can not break away from spirit and scope of the present utility model.Therefore, the utility model is not subjected to the restriction of specific embodiment disclosed herein, and all interior embodiment of claim scope that fall into the application belong to protection range of the present utility model.

Claims

1. overvoltage crowbar; it is characterized in that the overvoltage detecting that comprising links to each other for the voltage monitoring module (1) of detecting voltage and output monitoring output signal, with described voltage monitoring module (1) receives described monitoring output signal and output latch signal and latch module (2), the LED indicating module (4) that links to each other with latch module (2) and carry out power supply input control module (3) that power supply input controls, link to each other and indicate according to described latch signal with latch module (2) with described overvoltage detecting according to described latch signal with described overvoltage detecting.

2. overvoltage crowbar according to claim 1 is characterized in that, described voltage monitoring module (1) is for detecting a plurality of Zener diodes of a plurality of branches voltage simultaneously.

3. overvoltage crowbar according to claim 2 is characterized in that, the reverse-conducting voltage of described Zener diode is more than 1.1 times of described branch voltage.

4. overvoltage crowbar according to claim 2 is characterized in that, described voltage monitoring module (1) is exported described monitoring output signal when detecting one or more described branches voltage.

5. overvoltage crowbar according to claim 1 is characterized in that, described latch signal is low level signal.