CN203340054U

CN203340054U - DA switching circuit based on a PWM manner and optical coupling

Info

Publication number: CN203340054U
Application number: CN2013200643257U
Authority: CN
Inventors: 王文俊
Original assignee: HUBEI RONGTONG SANLI SCIENCE & TECHNOLOGY Co Ltd
Current assignee: HUBEI RONGTONG SANLI SCIENCE & TECHNOLOGY Co Ltd
Priority date: 2013-01-29
Filing date: 2013-01-29
Publication date: 2013-12-11
Anticipated expiration: 2023-01-29

Abstract

The utility model relates to the outdoor integrated cabinet for the communication station or the intelligent heat-exchanging system, and particularly to a DA switching circuit based on a PWM manner and optical coupling. The DA switching circuit based on the PWM manner and optical coupling comprises an optical-coupling primary circuit and an optical-coupling secondary circuit. The optical-coupling primary circuit comprises a luminous diode; one end of the luminous diode is connected to a PWM output terminal of a singlechip after being connected to an electric resistance serially; the optical-coupling secondary circuit comprises a photosensitive triode; the collector or the emitting electrode of the photosensitive triode outputs direct current control voltage through an RC charge-discharge circuit; a diode is connected between an integrating capacitor of the RC charge-discharge circuit and the collector or the emitting electrode of the photosensitive triode. The utility model provides the DA switching circuit based on a PWM manner and optical coupling which is reliable and widely applied.

Description

DA change-over circuit based on light lotus root and PWM mode

Technical field

The utility model relates to outdoor integrated cabinet or intelligent heat exchange system for communication base station, especially a kind of DA change-over circuit based on light lotus root and PWM mode.

Background technology

Automatic control occasion at communication base station with outdoor integrated cabinet, need the direct-current control voltage of output 0 to 10V, is used for adjusting rotary speed, air quantity, brightness, position, the information such as pressure, its basic demand is: continuous adjustable range is arranged, required precision is not high, other digital sensor feedback is arranged, and current common single-chip microcomputer all has PWM output, under actual demand, how utilizing the PWM of single-chip microcomputer to export to reach automatic control purpose is a technical barrier.

Summary of the invention

The purpose of this utility model is to overcome the shortcoming of prior art, and a kind of reliable and widely used DA change-over circuit based on light lotus root and PWM mode is provided.

For solving above technical problem, the technical solution of the utility model is: the DA change-over circuit based on light lotus root and PWM mode, its difference is: it comprises light lotus root primary circuit, light lotus root secondary circuit, light lotus root primary circuit comprises light-emitting diode, be connected to the Single Chip Microcomputer (SCM) PWM output after light-emitting diode one end series resistance, light lotus root secondary circuit comprises phototriode, the collector electrode of phototriode or emitter are by RC charge-discharge circuit output direct-current control voltage, be connected with a diode between the integrating capacitor of the collector electrode of described phototriode or emitter and RC charge-discharge circuit.

The utility model know-why is as follows:

1), when the PWM of single-chip microcomputer output low level, the light lotus root is elementary without glow current, thereby secondary cut-off, power supply charges to integrating capacitor by charging resistor;

2), when the PWM of single-chip microcomputer output high level, the light lotus root is elementary luminous, thereby secondary conducting, the voltage on integrating capacitor is by discharge resistance and the secondary discharge of light lotus root;

3), diode has two effects, the one, integrating capacitor C1 charging and discharging path is kept apart; The 2nd, utilize diode current flow pressure drop and light lotus root conduction voltage drop approximate identical and improve the circuit linearity.

The contrast prior art, technical solutions of the utility model have the following advantages:

1, succinct and can complete its function that realizes, cost be low;

2, input and output are isolated, and meet the safety utilization of electric power needs of various workplaces;

Though 3, this circuit forms for discrete device, but still need not adjust working point;

4, this circuit temperature characteristic good, float without temperature, applicable various adverse circumstances;

5, continuous tuning range is by the supply power voltage decision of output stage, generally uses 0 to 10V continuous adjustable voltage;

6, the combination of each two kinds of forms of input and output, totally four kinds of circuit; The circuit changed flexibly can be realized forward conversion and reverse conversion respectively;

7, the various PWM frequencies of complete adaptation, as shown in Figure 5, through our company's test, this circuit can perfectly adapt to the PWM frequency of 10kHz to 100kHz.

The accompanying drawing explanation

Fig. 1 is the circuit diagram of the utility model the first embodiment;

Fig. 2 is the circuit diagram of the utility model the second embodiment;

Fig. 3 is the circuit diagram of the utility model the 3rd embodiment;

Fig. 4 is the linear degrees of data of the test of the utility model the first embodiment.

Embodiment

Below by embodiment, by reference to the accompanying drawings the utility model is described in further detail.

Please refer to Fig. 1-Fig. 3, the DA change-over circuit of the utility model embodiment based on light lotus root and PWM mode, it comprises light lotus root primary circuit, light lotus root secondary circuit, light lotus root primary circuit comprises light-emitting diode, be connected to the Single Chip Microcomputer (SCM) PWM output after light-emitting diode one end series resistance R1, light lotus root secondary circuit comprises phototriode, the collector electrode of phototriode or emitter, by RC charge-discharge circuit output direct-current control voltage, are connected with a diode D1 between the integrating capacitor C1 of the collector electrode of described phototriode or emitter and RC charge-discharge circuit.

Concrete, referring to Fig. 1, in the utility model the first embodiment, when the PWM of single-chip microcomputer output low level, the light lotus root is elementary without glow current, thereby secondary cut-off, the 10V power supply, rushes electrical time constant and is approximately R2*C1(and ignores diode drop to integrating capacitor C1 charging by charging resistor R2, diode D1); When the PWM of single-chip microcomputer output high level, the light lotus root is elementary luminous, thereby secondary conducting, and the voltage on integrating capacitor C1 is by discharge resistance R3 and the secondary discharge of light lotus root, and be that R3*C1(ignores light lotus root conduction voltage drop discharge time); Diode D1 has two effects, and the one, integrating capacitor C1 charging and discharging path is kept apart; The 2nd, utilize diode current flow pressure drop and light lotus root conduction voltage drop approximate identical and improve the circuit linearity.

Above content is in conjunction with concrete execution mode further detailed description of the utility model, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, without departing from the concept of the premise utility, can also make some simple deduction or replace, all should be considered as belonging to protection range of the present utility model.

Claims

1. the DA change-over circuit based on light lotus root and PWM mode, it is characterized in that: it comprises light lotus root primary circuit, light lotus root secondary circuit, light lotus root primary circuit comprises light-emitting diode, be connected to the Single Chip Microcomputer (SCM) PWM output after light-emitting diode one end series resistance, light lotus root secondary circuit comprises phototriode, the collector electrode of phototriode or emitter, by RC charge-discharge circuit output direct-current control voltage, are connected with a diode between the integrating capacitor of the collector electrode of described phototriode or emitter and RC charge-discharge circuit.