CN201184905Y

CN201184905Y - Direct-current power supply polar monitor

Info

Publication number: CN201184905Y
Application number: CNU2008200667119U
Authority: CN
Inventors: 车勇
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-04-28
Filing date: 2008-04-28
Publication date: 2009-01-21
Anticipated expiration: 2018-04-28

Abstract

The utility model relates to a direct current power supply polarity monitor. A circuit structure of direct current power supply polarity monitor is a dual-port network circuit and the direct current power supply polarity monitor is characterized in that a negative polarity end of an output port (4) is connected with a drain of a special field effect transistor (3) for a N-channel, the negative polarity end of an input port (1) is connected with a source of the special field effect transistor (3) for the N-channel, a positive polarity end of the output port (4) is directly or indirectly connected with a gate of the special field effect transistor (3) for the N-channel through a resistor; a light-emitting diode (2) is connected with the resistor in series, and then the two are connected at the both ends of the input port (1) in parallel. The direct current power supply polarity monitor has simple structure and can use any power supply input port of electronic products with the direct current power supply, thereby protecting the electronic products from being damaged under the situation of reverse connection of power supply polarities, simultaneously generating an alarm of reverse connection and having very small circuit consumption and high efficiency.

Description

Direct supply polarity monitor

Technical field

The utility model relates to commodity, is a kind of direct supply polarity monitor specifically.

Background technology

At present numerous ultralow pressure electronic products is more and more abundanter, and these electronic products all need power supply to supply with without exception, no matter use battery also to be to use mains supply to transform to direct supply, all face the electric power polarity problem of a direct-current power supply, there are many people all to run into and damage because battery or electric power polarity connect the electrical equipment that causes on the contrary, connect anti-or the outside connects anti-and inserts by force if more typical example is USB mouth when installation internal wiring of computer, moment will be caused short circuit, and therefore slight error but may cause heavy losses.If can unify power interface and correct automatically identification electric power polarity, for the consumer group of whole electronic product, will save down huge fund waste.

But the obstacle of pendulum before this simple problem is at present, the common diode of making single-way switch in the ultralow pressure rectification because itself pressure drop nearly just has or slightly surpass 1v,, obviously be inappropriate for example for the electronic product of a 1.5V monocell power supply.For the battery-powered product of two economize on electricitys, this commutation diode can't be brought into play efficient and make load voltage low excessively.

Along with the develop rapidly of semiconductor foundation investigation of materials, the special-purpose field effect transistor of the present ultralow internal resistance that has occurred and become the marketization, low level control presents in a large number, makes above-mentioned technology become possibility.

Summary of the invention

The purpose of this utility model provide a kind of high efficiency, can be used for ultralow pressure direct current power source supplying power polarity monitor.

Described direct supply polarity monitor, its circuit structure is a kind of two-port network circuit, it is characterized in that: the negative polarity of its output port 4 terminates to the drain electrode of the special-purpose field effect transistor 3 of N raceway groove, the negative polarity of input port 1 terminates to the source electrode of the special-purpose field effect transistor 3 of N raceway groove, and the positive ends of output port 4 directly or receive the grid of the special-purpose field effect transistor 3 of N raceway groove by resistance; Light emitting diode 2 and the two ends that are parallel to input port 1 after resistance is connected.

The utility model circuit structure is simple, can use the power input mouth at the electronic product of any direct current supply, guarantee Low-voltage Electronic product connects under the anti-situation in power supply polarity and is not damaged, and produces simultaneously and connects anti-warning, and circuitry consumes is minimum, the efficient height.

Description of drawings

Fig. 1 is the utility model structural representation.

Among the figure: 1-input port, 2-light emitting diode, the special-purpose field effect transistor of 3-, 4-output port, 5-load.

Embodiment

Below in conjunction with accompanying drawing the utility model is further specified: direct supply polarity monitor as shown in fig. 1, its circuit structure is a kind of two-port network circuit, it is characterized in that: terminate to the drain electrode of the special-purpose field effect transistor 3 of N raceway groove in the negative polarity of output port 4, the negative polarity of input port 1 terminates to the source electrode of the special-purpose field effect transistor 3 of N raceway groove, and the positive ends of output port 4 directly or receive the grid of the special-purpose field effect transistor 3 of N raceway groove by resistance; Light emitting diode 2 and the two ends that are parallel to input port 1 after resistance is connected.

Usually the special-purpose field effect transistor 3 of this kind is called as synchronous rectifier.As seen from Figure 1, when external power source input connection is correct, the grid of special-purpose field effect transistor 3 obtains high level, make leakage, the source electrode conducting of special-purpose field effect transistor 3, because leakage, the internal resistance between source electrode of special-purpose field effect transistor 3 are minimum, this internal resistance that multiple product is arranged at present below 10 milliohms, 20 amperes of big electric currents by the time 0.2 volt pressure drop is still only arranged, the pressure drop that the load current below 1 ampere produces is especially less than 0.01 volt.When if the anode of light emitting diode 2 is received the negative terminal of input port 1, light emitting diode 2 is not lighted.

Connect inverse time and work as the external power source input, the grid of special-purpose field effect transistor 3 is a low level, the leakage of this special use field effect transistor 3, not conducting of source electrode, and light emitting diode 2 is lighted warning simultaneously, thereby has also protected load 5 not to be damaged.

This ball bearing made using can be concatenated into the power input mouth of any DC electronic product, or directly accomplishes in the circuit, plays the protection product and does not damage because of electric power polarity connects on the contrary, simultaneously the normal use of product be we can say almost without any influence.

Claims

1. direct supply polarity monitor, its circuit structure is a kind of two-port network circuit, it is characterized in that: the negative polarity of its output port (4) terminates to the drain electrode of the special-purpose field effect transistor of N raceway groove (3), the negative polarity of input port (1) terminates to the source electrode of the special-purpose field effect transistor of N raceway groove (3), and the positive ends of output port (4) directly or receive the grid of the special-purpose field effect transistor of N raceway groove (3) by resistance; Light emitting diode (2) and the two ends that are parallel to input port (1) after resistance is connected.